Chapter 5 Quantifying Greenhouse Gas Sources and …...Chapter 5: Quantifying Greenhouse Gas Sources...

Authors:WendyPowers,MichiganStateUniversity(LeadAuthor)BrentAuvermann,TexasA&MUniversityN.AndyCole,USDAAgriculturalResearchServiceCurtGooch,CornellUniversityRichGrant,PurdueUniversityJerryHatfield,USDAAgriculturalResearchServicePatrickHunt,USDAAgriculturalResearchServiceKristenJohnson,WashingtonStateUniversityAprilLeytem,USDAAgriculturalResearchServiceWeiLiao,MichiganStateUniversityJ.MarkPowell,USDAAgriculturalResearchService

Contents:5 QuantifyingGreenhouseGasSourcesandSinksinAnimalProductionSystems..............5‐5

5.1 Overview...........................................................................................................................................................5‐55.1.1 OverviewofManagementPracticesandResultingGHGEmissions.........................5‐55.1.2 SystemBoundariesandTemporalScale............................................................................5‐125.1.3 SummaryofSelectedMethods/Models/SourcesofData...........................................5‐125.1.4 OrganizationofChapter/Roadmap......................................................................................5‐14

5.2 AnimalProductionSystems....................................................................................................................5‐185.2.1 DairyProductionSystems........................................................................................................5‐185.2.2 BeefProductionSystems..........................................................................................................5‐225.2.3 SheepProductionSystems.......................................................................................................5‐255.2.4 SwineProductionSystems......................................................................................................5‐255.2.5 PoultryProductionSystems....................................................................................................5‐28

5.3 EmissionsfromEntericFermentationandHousing.....................................................................5‐305.3.1 EntericFermentationandHousingEmissionsfromDairyProductionSystems.......

.............................................................................................................................................................5‐315.3.2 EntericFermentationandHousingEmissionsfromBeefProductionSystems.5‐445.3.3 EntericFermentationandHousingEmissionsfromSheep.......................................5‐525.3.4 EntericFermentationandHousingEmissionsfromSwineProductionSystems......

.............................................................................................................................................................5‐535.3.5 HousingEmissionsfromPoultryProductionSystems................................................5‐605.3.6 EntericFermentationandHousingEmissionsfromOtherAnimals......................5‐645.3.7 FactorsAffectingEntericFermentationEmissions.......................................................5‐665.3.8 LimitationsandUncertaintyinEntericFermentationandHousingEmissionsEstimates.........................................................................................................................................................5‐73

5.4 ManureManagement.................................................................................................................................5‐75

Chapter 5Quantifying Greenhouse Gas Sources and Sinks in Animal Production Systems

Chapter 5: Quantifying Greenhouse Gas Sources and Sinks in Animal Production Systems

5-2

5.4.1 TemporaryStackandLong‐TermStockpile.....................................................................5‐775.4.2 Source:U.S.EPA(2011).Composting..................................................................................5‐815.4.3 AerobicLagoon.............................................................................................................................5‐855.4.4 AnaerobicLagoon,RunoffHoldingPond,StorageTanks............................................5‐865.4.5 AnaerobicDigesterwithBiogasUtilization......................................................................5‐915.4.6 CombinedAerobicTreatmentSystems..............................................................................5‐935.4.7 Sand‐ManureSeparation..........................................................................................................5‐945.4.8 NutrientRemoval........................................................................................................................5‐945.4.9 Solid–LiquidSeparation............................................................................................................5‐955.4.10 ConstructedWetland.................................................................................................................5‐975.4.11 Thermo‐ChemicalConversion................................................................................................5‐985.4.12 LimitationsandUncertaintyinManureManagementEmissionsEstimates......5‐99

5.5 ResearchGaps............................................................................................................................................5‐1055.5.1 EntericFermentation..............................................................................................................5‐1055.5.2 ManureManagement..............................................................................................................5‐106

Appendix5‐A:EntericCH4fromFeedlotCattle–MethaneConversionFactor(Ym)..............5‐109Appendix5‐B:FeedstuffsCompositionTable...........................................................................................5‐113Appendix5‐C:EstimationMethodsforAmmoniaEmissionsfromManureManagementSystems.....................................................................................................................................................................5‐123

5‐C.1 MethodforEstimatingAmmoniaEmissionsUsingEquationsfromIntegratedFarmSystemModel...............................................................................................................................5‐123

5‐C.1.1RationaleforSelectedMethod...............................................................................5‐1235‐C.1.2ActivityData..................................................................................................................5‐1235‐C.1.3AncillaryData...............................................................................................................5‐124

5‐C.2 MethodforAmmoniaEmissionsfromTemporaryStack,Long‐TermStockpile,AnaerobicLagoons/RunoffHoldingPonds/StorageTanks,andAerobicLagoons.....5‐1245‐C.3 MethodforEstimatingAmmoniaEmissionsfromCompostingUsingIPCCTier2Equations....................................................................................................................................................5‐128

5‐C.3.1RationaleforSelectedMethod...............................................................................5‐1285‐C.3.2ActivityData..................................................................................................................5‐1295‐C.3.3AncillaryData...............................................................................................................5‐129

5‐C.4 MethodforAmmoniaEmissionsfromComposting..................................................5‐1295‐C.5 UncertaintyinAmmoniaEmissionsEstimates...........................................................5‐129

Appendix5‐D:ManureManagementSystemsShapeFactors( )...................................................5‐131Appendix5‐E:ModelReview:ReviewofEntericFermentationModels.......................................5‐134Chapter5References..........................................................................................................................................5‐139

SuggestedChapterCitation:Powers,W.,B.Auvermann,A.Cole,C.Gooch,R.Grant,J.Hatfield,P.Hunt,K.Johnson,A.Leytem,W.Liao,J.M.Powell,2014.Chapter5:QuantifyingGreenhouseGasSourcesandSinksinAnimalProductionSystems.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntity‐ScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington.DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.Riley‐Gilbert,andS.Biggar,Eds.

USDAisanequalopportunityproviderandemployer.


5-3

Acronyms,ChemicalFormulae,andUnitsAA AminoacidsAD AnaerobicdigestionADF AciddetergentfiberAGP AntibioticgrowthpromotersASABE AmericanSocietyofAgricultural andBiological EngineersB0 MaximummethaneproductioncapacitiesbLS backwardLagrangianstochasticBNR BiologicalnitrogenremovalBW BodyweightCH4 MethaneCNCPS CornellNetCarbohydrateandProteinSystemCO2‐eq CarbondioxideequivalentsCP CrudeproteinCSTR ContinuousstirredtankreactorDDGS DrieddistillersgrainswithsolublesDE DigestibleenergyDFM DirectfedmicrobialsDGS DistillersgrainswithsolublesDIP DietarycrudeproteinDMI DrymatterintakeDRC Dry‐rolledcornEF Emissionfactorg GramsGg GigagramsGEI GrossenergyintakeGHG GreenhousegasHCW HotcarcassweightHMC High‐moisturecornIFSM IntegratedFarmSystemModelkcal Kilocaloriekg Kilogramslb(s) Pound(s)LCA LifecycleanalysisLU Livestockunitm MetersMCF MethaneconversionfactorME Metabolizableenergymg MilligramMGA MelengestrolacetateMJ MillijoulesNE NetenergyNex NitrogenexcretedN NitrogenN2O NitrousoxideNDF NeutraldetergentfiberNFC Non‐fibercarbohydrateNH3 AmmoniaNPN Non‐proteinnitrogen


5-4

NSP Non‐starchpolysaccharideO2 OxygenOM Organicmatterppb partsperbillionppm partspermillionRDP RuminaldegradableproteinRFI ResidualfeedintakeRMSPE ResidualmeansquarepredictionerrorSF6 SulfurhexafluorideSFC Steam‐flakedcornTAN TotalammoniacalnitrogenTDN TotaldigestiblenutrientsTKN TotalKjeldahlnitrogenTMR TotalmixedrationUASB UpflowanaerobicsludgeblanketUP UnprocessedU.S.EPA U.S.EnvironmentalProtectionAgencyVFA VolatilefattyacidsVS VolatilesolidsWDGS WetdistillersgrainswithsolublesYm Methaneconversionfactor,percentofgrossenergyinfeedconverted

tomethane


5-5

5 QuantifyingGreenhouseGasSourcesandSinksinAnimalProductionSystems

Thischapterprovidesguidanceforreportinggreenhousegas(GHG)emissionsassociatedwithentity‐levelfluxesfromanimalproductionsystems.Inparticular,itfocusesonmethodsforestimatingemissionsfrombeefcattle(cow‐calf,stocker,andfeedlotsystems),dairycattle,sheep,swine,andpoultry(layers,broilers,andturkey).Informationprovidedisbasedonavailabledataatthetimeofwriting.Inmanycasessystemsareoversimplifiedbecauseoflimiteddataavailability.Itisexpectedthatmoredatawillbecomeavailableovertime.Thischapterprovidesinsightintothecurrentstateofthescienceandservesasastartingpointforfutureassessments.

Section5.1summarizesanimalmanagementpracticesandtheresultingGHGemissions. Section5.2presentsanoverviewofeachproductionsystemandageneraldiscussionof

commonmanagementsystemsandpractices.

Section5.3describesthemethodsforestimatingGHGemissionsfromentericfermentationandhousing(entericfermentationbeingamuchmoresignificantemissionssourcethan

housing).

Section5.4describesmethodsforestimatingGHGsfrommanuremanagementsystems. Section5.5identifiesresearchgapsthatexistforquantifyingGHGsfromanimalproduction

systems.Theintentofidentifyingresearchgapsistohighlightwhereimprovementsin

knowledgecanbestimprovetheusefulnessofthisdocumentatfarm‐,regional‐,and

industry‐scales.

5.1 Overview

ThissectionsummarizesthekeypracticesinanimalmanagementandtheresultingGHGemissionsthatarediscussedindetailinthischapter.Theagriculturalpracticesdiscussedincludethoserequiredtobreedandhouselivestock,includingthemanagementofresultantlivestockwaste.Emissionsconsideredhereincludethosefromentericfermentation(resultingfromlivestockdigestiveprocesses),livestockwasteinhousingareas,andlivestockwastemanagedinsystems(suchasstockpiles,lagoons,digesters,solidseparation,andothers).OptionsformanagementchangesthatmayresultinchangesinGHGemissionsarealsodiscussed.

5.1.1 OverviewofManagementPracticesandResultingGHGEmissions

Animalproductionsystemsincludeagriculturalpracticesthatinvolvebreedingandrearinglivestockformeat,eggs,dairy,andotheranimalproductssuchasleather,wool,fur,andindustrial

AmmoniaEmissionsinAnimalProductionSystems

Ammonia(NH3),althoughnotaGHG,isemittedinlargequantitiesfromanimalhousingandmanuremanagementsystemsandisanindirectprecursortonitrousoxide(N2O)emissionsaswellasanenvironmentalconcern.Insidebarnsandhousingunits,NH3isconsideredanindoorairqualityconcernbecauseitcanhaveanegativeimpactonanimalhealthandproduction.Volatilizedammoniacanreactwithothercompoundsintheairtoformparticulatematterwithadiameterof2.5microns.Thisfineparticulatemattercanpenetrateintothelungs,causingrespiratoryandcardiovascularproblems,andcontributetotheformationofhaze.

InformationaboutammoniahasbeenincludedinthischapterandproposedquantificationmethodsarepresentedinAppendix5‐C.


5-6

productslikeglueoroils.Farmersandotherfacilityownersraiseanimalsineitherconfined,semi‐confinement,orunconfinedspaces;thepracticesusedtoraisethemaredependentonanimaltype,region,landavailability,andindividualpreferences(e.g.,conventionalor“organic”standards).Regardlessoftheconditionsinwhichanimalsareraisedandhoused,theyproduceGHGemissions.Themagnitudeofemissionsdependsprimarilyonthequalityofthediet,theanimals’requirementsandintake(e.g.,grazing,pregnant,lactating,performingwork),andthetypesofsystemsinplacetomanagemanure.Theprimarysourceofmethane(CH4)emissionsfromanimalproductionsystemsisentericfermentation,whichisaresultofbacterialfermentationduringdigestionoffeedinruminantanimals.Thesecondlargestsourceofemissionsfromanimalproductionsystemsisfromthemanagementoflivestockmanure.Methaneemissionsalsooccurfromthedigestiveprocessesinmonogastricanimals;however,thequantityissignificantlylessthantheseothertwosources.Forsimplicity,inthereport,thetermentericfermentationreferstoemissionsfromthedigestiveprocessofbothruminantandmonogastricanimals.

Manuremanagementisthecollection,storage,transfer,andtreatmentofanimalurineandfeces.Storageofanimalmanurehasbecomeincreasinglypopularasitallowssynchronizationoflandapplicationofmanurenutrientswithcropneeds,reducestheneedforpurchasedcommercialfertilizer,andreducespotentialforsoilcompactionduetopoortimingofmanureapplication.Dependingonthestorageandtreatmentpractices,manuremanagementhastheaddedbenefitofreducingairandwaterpollution.However,manurestoredinanaerobicconditionsresultsintheproductionandpotentialreleaseofGHGsandodors.Greenhousegasemissionsfromthreesolidmanurestorage/treatmentpractices(temporarystackandlong‐termstockpile,composting,andthermo‐chemicalconversion)andeightliquidmanurestorage/treatmentpractices(aerobiclagoon,anaerobiclagoon/runoffholdingpond/storagetanks,anaerobicdigestion,combinedaerobictreatmentsystem,sand‐manureseparation,nutrientremoval,solid‐liquidseparation,andconstructedwetland)areconsideredinthereport.

Figure5‐1providesanoverviewoftheconnectionsbetweenfeed,animals,manure,andGHGemissionsinananimalproductionsystem.Atthetopoftheconceptualmodel,livestockarefedavarietyofdiets.Ruminantanimalseatfeedstuffsand,throughfermentationbytheruminalmicrobes,CH4isproduced.Poultryandswine,althoughtheydonotreleaseasignificantamountofCH4throughentericfermentation,depositmanureintobedding,anduponmanuredecomposition,mayreleasenitrousoxide(N2O),CH4andammonia(NH3)intotheatmosphere.Methodologytoestimateemissionsfrombeddinganddrymanureinhousingissimilarto,andoftenparallelto,themethoddescribedfordrymanurehandlingandstoragesystems.Manurefromgrazinglivestockisleftonfieldsorpaddocks,andthemanuremaybecollectedtobetreatedandstored.Manurethathasbeencollectedandstoredcanbeappliedtocroplands.GHGemissionsfromgrazinglandsandcroplandsareaddressedinChapter3,QuantifyingGreenhouseGasSourcesandSinksinCroplandandGrazingLandSystems.


5-7

Figure5‐1:ConnectionsBetweenFeed,Animals,Manure,andGHGforAnimalAgriculture


5-8

5.1.1.1 ResultantGHGEmissions

Forthisreport,methodsarecategorizedaccordingtothosefromentericfermentation,housing,andmanuremanagementsystems.Thehousingdiscussionincludesemissionsfrommanuredepositedinthehousingunitandmanurethatismanagedinsidethoseareas(suchasinteriorstockpiles).Manuremanagementincludesemissionsfrommanaged,treated,andstoredmanure.1

EntericFermentationandHousingEmissionsMethane‐producingmicroorganisms,calledmethanogens,existinthegastrointestinaltractofmanyanimals.However,thevolumeofCH4emittedbyruminantsisvastlydifferentfromthatofotheranimalsbecauseofthepresenceandfermentativecapacityoftherumen.Intherumen,CH4formationisadisposalmechanismbywhichexcesshydrogenfromtheanaerobicfermentationofdietarycarbohydratecanbereleased.Controlofhydrogenionsthroughmethanogenesisassistsinmaintenanceofefficientmicrobialfermentationbyreducingthepartialpressureofhydrogentolevelsthatallownormalfunctioningofmicrobialenergytransferenzymes(Morgavietal.,2010).TheonlyGHGofconcernresultingfromentericfermentationisCH4.RespirationchambersequippedwithN2OanalyzersindicatethatentericfermentationdoesnotresultintheproductionofN2O(Reynoldsetal.,2010).Methanecanalsoarisefromhindgutfermentation,butthelevelsassociatedwithhindgutfermentationaremuchlowerthanthoseofforegutfermentation.

Becausethemagnitudeofentericemissionsissogreatand,therefore,asignificantcontributortomanycountries’GHGemissions,decadesofresearchhavegoneintocharacterizing,understanding,andattemptingtomitigateentericCH4emissions.Afundamentalchallengeinthistypeofresearchhasbeenthemeasurementoftheseemissions.

Methane,N2O,carbondioxide(CO2),andNH3areproducedfromlivestockfecesandurine,andsomegaseousformsareemittedsoonaftermanureexcretion.Indry‐lotsituations,fecesandurinearedepositedonthepensurfaceandaremixedviaanimalhoofaction.MicroorganismsinthefecesorunderlyingsoilmetabolizenutrientsinthemanuretoproduceGHGs.Infeedlots,wheremanureisnormallycleanedfrompensonceortwiceperyear,distinctive,hard‐packedlayersofmanureandsoilmaydevelopthatproducemicroenvironmentsfavorabletooxidativeandreductiveprocesses(Woodburyetal.,2001;Coleetal.,2009b).Periodsofrainfallordryconditionsmayalterthemicrobialandchemicalnatureofthepensurface.ProductionofCH4andN2Ooccurintheunderlyingmanure/soillayersandinwater‐saturatedareaswhereoxygenislimited,suchaswetareasofthepenaroundwatertroughsanddepressionsthatcollectrainwaterandsnowmelt.Incontrast,mostNH3producedinthepenprobablycomesfromfreshurinespotsonthepensurface.Todate,fewmeasurementsofGHGemissionsfromfeedlotordry‐lotpensurfaceshavebeenmade.

Runofffromdry‐lotandfeedlotpensisnormallycollectedinretentionponds(moretypicalinfeedlots),orlagoons(morecommonindairies).Insomecases,runoffmayundergopartialremovalofsuspendedsolidsinsettlingbasins(feedlotsanddairies)orinmechanicalseparators(dairiesonly)thatparallelstreatmentofmanurecollectedinthesesamesystems.LossesofGHGsandNH3

1EmissionsfrommanuredepositedongrazinglandsareaddressedinChapter3:CroplandsandGrazingLands.

Background:Ruminants

Ruminantsareanimalsthathavefour‐chamberedstomachs,whichallowforeasierdigestionofhigh‐fiber,hard‐to‐digestfeedstuffs.Theyinclude: Cattle Goats Sheep Deer AmericanBison


5-9

fromthesefacilitiesdependuponclimaticfactorsandtheoxidative‐reductivepotential,pH,andchemistryoftheeffluentinthepondorlagoon.AlimitednumberofstudieshavemeasuredGHGorNH3emissionsfromretentionpondsorlagoons.

ManureManagementManureismanagedinawidevarietyofsystems.TheresultingGHGemissionsdifferbyGHGandmagnitudeofemissionsperquantityofmanure.Table5‐1providesanoverviewoftheliquidandsolidmanuresystemsconsideredinthisreportandtheresultingGHGs.

Table5‐1:OverviewofManureManagementSystemsandAssociatedGreenhouseGases

StorageandTreatmentPractices

EstimationMethod Description

CH4 N2O NH3a

SolidManure

Temporaryandlong‐termstorage

Manuremaybestoredtemporarilyforafewweekstoavoidlandapplicationduringunfavorableweatheroritcanbestoredforseveralmonths.

Composting

Compostinginvolvesthecontrolledaerobicdecompositionoforganicmaterialandcanoccurindifferentforms.Estimationmethodsareprovidedforinvessel,staticpile,intensivewindrow,andpassivewindrowcomposting.

Thermo‐chemicalconversion

Thermo‐chemicalconversioninvolvesthecombustionofanimalwaste,convertingCH4toCO2.Pyrolysis/gasificationisonemethodthathasreceivedmuchinterest.NomethodisprovidedasGHGsareconsiderednegligible.

LiquidManure

Aerobiclagoon Aerobiclagoonsinvolvethebiologicaloxidationofmanureasaliquidwithnaturalorforcedaeration.

Anaerobiclagoon/runoffholdingponds/storagetanks

Anaerobiclagoonsareearthenbasinsthatprovideanenvironmentforanaerobicdigestionandstorageofanimalwaste.Lagoonsmaybecoveredoruncoveredandhaveacrustornocrustformation.Runoffandholdingpondsareconstructedtocaptureandstorerunofffromfeedlotsanddry‐lots.Insomecaseswashwaterfromdairyparlorsmaybestoredinholdingponds.Storagetankstypicallystoreslurryorwastewaterthatwasscrapedorpumpedfromhousingsystems.

Combinedaerobictreatmentsystem

Thisprocessinvolvesremovingsolidsusingflocculationandthencompostingthesolidstreamandaeratingtheliquidstreamofmanure.

Anaerobicdigester

Anaerobicdigestersaremanuretreatmentsystemsdesignedtomaximizeconversionoforganicwastesintobiogas.Thesecanrangefromcoveredanaerobiclagoonstohighlyengineeredsystems.MethanegasleakageisthemainsourceofGHGemissions;NH3andN2Oleakageisnegligible.

Sand–manureseparation

Manureisseparatedfromsandandbeddingbymechanicalandsedimentationseparation.Nomethodisprovidedasemissionsarenegligible.Separatedliquidsandsolidscouldbeinputsintootherstoragesystems.

Nutrientremoval

Therearefourmainnitrogenremovalapproaches:biologicalnitrogenremoval,Anammox(i.e.,anaerobicammoniumoxidation),NH3stripping,ionexchange,andstruvitecrystallization.NomethodisprovidedduetolimitedquantitativeinformationonGHGgenerationfromnutrientremovalsystems.


5-10

StorageandTreatmentPractices

EstimationMethod Description

CH4 N2O NH3a

Solid–liquidseparation

Mechanicalseparationofliquidsandsolidsthroughscreens,centrifuges,pressing,filtration,ormicroscreening.Separatedliquidsandsolidscouldbeinputsintootherstoragesystems.

Constructedwetland

Typicallyconsistofwetlandplantsgrowinginabedofhighlyporousmedia.Nomethodisprovidedasemissionsarenegligible;GHGsinksarenotedtolikelybegreaterthanemissions.

aAlthoughNH3isconsideredinthischapterasanimportantprecursortoparticulateformulation(affectingradiationbalance)andGHGsandisakeyelementofdiscussion,NH3itselfisnotaGHG.Therefore,methodsforestimatingNH3emissionsareprovidedinAppendix5‐C.

AnentitycanreduceitsGHGemissionsfrommanurebyutilizingalternativetreatmentoptionsand/ormanagementsystems.AnaerobicdigestersdonotreducetheamountofCH4releasedbutofferanoptiontocaptureandconverttheCH4toCO2andenergythroughcombustion.DigestersofferbothCH4reductionsaswellasGHGavoidancebyreducinganentity’selectricitydemand.

5.1.1.2 ManagementInteractions

Table5‐2depictsthekeytypesofinformationdesiredforestimatingGHGemissionsfromananimalproductionfacility.Thistableillustratestheattributesofasystemthathavethegreatestinfluenceoveremissionswithineachcomponent.AnumberofexistingmodelscanbeusedtoestimateGHGemissionsthatutilizethekeyactivitydataindicatedinTable5‐2.

Table5‐2:DesiredActivityandAncillaryDataforEstimatingGHGEmissionsfromAnimalProductionSystems

GeneralCategory SpecificData

CattleSheep Swine Poultry Goats

Amer.BisonCow–

calfStockers Feedlot Dairy

Animal

Characteristics Bodyweight ● ● ● ● ● ● ● ● ●

Bodyconditionscore ● ● ● ●

Stageofproduction(dry,lactating,pregnant)

● ● ●

Dieta

ry

Facto Dietintake(orfactorsthatcanbeusedtopredictintake)

● ● ● ● ● ● ● ● ●

CombinedAerobicTreatmentComparedtoAnaerobicLagoons

Acombinedaerobictreatmentsysteminvolvesthetreatmentofamanurestreamwithflocculantstoremovethemajorityofsolidsfromthestream.Thesolidsportioniscompostedwhiletheremainingliquidistransferredtoastoragetankwhereitisaerated.MethaneisavoidedbyaerobicallytreatingthesolidsviacompostingwhileNH3inthewastewaterisavoidedvianitrification.TheGHGsresultingfromacombinedaerobictreatmentareonly10percentofwhatwouldbeemittedfromananaerobiclagoon,thuscombinedaerobictreatmentsrepresentapotentialmitigationoptionforentities.


5-11

GeneralCategory SpecificData

CattleSheep Swine Poultry Goats

Amer.BisonCow–

calfStockers Feedlot Dairy

Typeofforage(conservedorgrazed,pasturecomposition,stageofplantgrowth)

● ● ● ● ● ●

Dietdrymatterintake,crudeprotein,neutraldetergentfiber,aciddetergentfiber,non‐structuralcarbohydrates,fiber,fat,energycontent

● ● ● ● ● ● ● ● ●

Dietdigestibilityand/orrateofpassage

● ● ● ● ● ●

Degradabilityofcarbohydratesandproteins

● ● ●

Supplementationpractices– type(e.g.,grains,protein,liquid,dryblocks,non‐proteinnitrogen)andquantity

● ● ● ● ●

Supplementalordietionophoreconcentration

● ● ● ●

Dietarybeta‐agonists ● ●

Nutrient

Excretion:

Quantity

Carbon,nitrogen,andvolatilesolids

● ● ● ● ● ● ● ● ●

Other

Animal

Factors

Growthpromotingimplants

● ●

ManureManagem

entFactors

Animalmanagementregimenusedtospreadmanureoverpasturetoreduceconcentrationnearwaterorfeedsources

● ● ● ● ● ●

Soiltype ● ● ● ● ● ● ● ● ● Practicestocontrolrunofffrompastures/lots/fields

● ● ● ● ● ● ● ● ●

Ifhoused,thelengthoftimetheyarehoused,animalconcentration,manurehandlingprocedures

● ● ● ● ● ● ● ● ●

Typeofmanurecollection/storagesystem

● ● ● ● ●

Frequencyofmanurecollectionsandcomposition

● ● ● ● ●

Bedding/litteruseandsource

● ● ● ● ●


5-12

5.1.2 SystemBoundariesandTemporalScale

Systemboundariesaredefinedbythecoverage,extent,andresolutionoftheestimationmethods.ThemethodsinthisreportcanbeusedtoestimateGHGemissionsourcesthatoccurwithintheproductionareaofananimalproductionsystem,includingtheanimals,animalhousing,andmanurehandling,treatment,andstorage.Methaneemissionsfromentericfermentation,aswellastheCH4andN2Oemissionsfrommanuremanagementsystemsormanurestoredinhousing,areconsideredinthisreport.Ammonia,whilenotaGHG,isaprecursortoN2Oformationandis,therefore,included,primarilyinAppendix5‐C.Theactoftransportingmanuretothefieldforlandapplicationisincludedintheproductionareaboundary,butemissionsfromvehicletransportarenotincludedinthescopeofthisreportastherearemanyvariablesthatwoulddetermineemissionsfromvehicles(ageofvehicle,type,fuelefficiency,idletime),andtheyarenotdirectagriculturalemissionsandcouldinsteadbeconsideredpartofthetransportsector(off‐road).Additionally,thisreportdoesnotencompassafulllifecycleanalysis(LCA)ofGHGemissionsfromanimalproductionsystems.TheadjacenttextboxsummarizesseveralstudiesonLCAsforanimalproductionsystems;however,theyarenotutilizedinthisreport.EmissionsthatresultfollowingmanureapplicationareaddressedseparatelyinChapter3,QuantifyingGreenhouseGasSourcesandSinksinCroplandandGrazingLandSystems.

Foremissionsfromanimalproductionsystems,themethodsprovidedhavearesolutionofindividualherdswithinanentity’soperation.Aherdisdefinedasagroupofanimalsthatarethesamespecies,grazeonthesameparcelofland(samedietcomposition),andutilizethesamemanuremanagementsystems.Emissionsareestimatedforeachindividualherdwithinanoperationandthenaddedtogethertoestimatethetotalanimalproductionemissionsforanentity.Theanimalproductiontotalsarethencombinedwithemissionsfromcroplands,grazinglands,andforestrytodeterminetheoverallemissionsfromtheoperationbasedonthemethodsprovidedinthisdocument.Emissionsareestimatedonanannualbasis.

5.1.3 SummaryofSelectedMethods/Models/SourcesofData

TheIntergovernmentalPanelonClimateChange(IPCC,2006)hasdevelopedasystemofmethodologicaltiersrelatedtothecomplexityofdifferentapproachesforestimatingGHGemissions.Tier1representsthesimplestmethods,usingdefaultequationsandemissionfactorsprovidedintheIPCCguidance.Tier2usesdefaultmethods,butemissionfactorsthatarespecifictodifferentregions.Tier3usescountry‐specificestimationmethods,suchasaprocess‐basedmodel.ThemethodsprovidedinthisreportrangefromthesimpleTier1approachestothemostcomplexTier3approaches.Higher‐tiermethodsareexpectedtoreduceuncertaintiesintheemissionestimates,ifsufficientactivitydataandtestingareavailable.

EstimatingCH4emissionsfromentericfermentationinswine,goats,Americanbison,llamas,alpacas,andmanagedwildlifeuseTier1methods.EntericemissionsfromsheepareestimatedusingtheHowdenequation(Howdenetal.,1994),andemissionsfromdairyproductionsystemsareestimatedusingtheMitscherlich3(Mits3)equation(Millsetal.,2003)asprovidedintheDairyGasEmissionsModel(DairyGEM)(Rotzetal.,2011a).EmissionsfrombeefcowsareestimatedusingtheIPCCTier2approach.EmissionsfromfeedlotsareestimatedusingamodificationoftheIPCCTier2approach.

QualitativeDiscussiononManureSources

Estimationmethodsarenotavailableforsomesources.Qualitativediscussionisprovidedfor:

Sand‐ManureSeparation NutrientRemoval Solid‐LiquidSeparation ConstructedWetlands Thermo‐chemicalConversion


5-13

Formanuremanagement,theIPCCTier2methodologyisusedforCH4emissionsfromtemporarystackandlong‐termstockpile,CH4andN2Oemissionsfromcomposting,andN2Oemissionsfromaerobiclagoons.TheSommermodelisusedtoestimateCH4emissionsfromanaerobiclagoons.

Allmethodsincludearangeofdatasourcesfromoperation‐specificdatatonationaldatasets.Operation‐specificdatawillneedtobecollectedbytheentityandgenerallyareactivitydatarelatedtothefarmandlivestockmanagementpractices(e.g.,dietaryinformation,volatilesolidscontentofmanure).Nationaldatasetsarerecommendedforancillarydatarequirements,suchasclimatedataandsoilcharacteristics.

AsummaryofproposedmethodsandmodelsforestimatingGHGemissionsfromanimalproductionsystemsisprovidedinTable5‐3.

Life Cycle Analysis of Cattle Production Systems

Petersetal.(2010)reportedthattheestimatedcarbonfootprintofcattleproductionsystemsaroundtheworldrangedfrom8.4kgofCO2‐eq(kgHCW)‐1(HCW=hotcarcassweight)inanAfricanpastoralsystemto25.5kgCO2‐eq(kgHCW)‐1inanintensiveJapanesegrainfeedingsystem.FiveNorthAmericanstudies(Vergeetal.(2008)andBeaucheminetal.(Sweeten,2004;2010)inCanada,Pelletieretal.(2010)andLupoetal.(2013)intheU.S.Midwest,andStackhouseetal.(2012)andStackhouse‐Lawsonetal.(2012)inCalifornia)estimatedthecarbonfootprintofvariousbeefcattleproductionsystems:Thecarbonfootprintforthetotalbeefproductionsystemsrangedfrom10.4to19.2kgCO2‐eq(kgfinalbodyweight)‐1(or16.7to32.5kgCO2‐eq(kgHCW)‐1).Sixtyfourto80percentofthetotalCO2‐eqwasproducedinthecow‐calfsectorofproduction;whereas8to20percentofCO2‐eqwasproducedinthestockerphase,andonly12to16percentwasproducedduringthefinishingphase.Themajority(55to63percent)ofthetotalCO2‐eqwasentericCH4,18to23percentwasmanureN2O,and14to24percentwasfromfossilenergyuseandsecondaryemissions.

Ingeneral,thedailycarbonfootprintwasgreaterduringthegrazing(stocker)phasethanduringthefeedlotfinishingphase.BothPelletieretal.(2010)andStackhouseetal.(2012)reportedthatthecarbonfootprintwasslightlylowerforcalvesthatwereweanedandwentdirectlytothefeedlot(21.1and23.0kgCO2‐eq(kgHCW)‐1or2,382and3,493kghead‐1,respectively)thanforcattlethatwentthroughastockergrazingphasebeforeenteringthefeedlot(22.6and26.1kgCO2‐eq(kgHCW)‐1or2,904and4,522kgCO2‐eqhead‐1,respectively).Pelletieretal.(2010)andLupoetal.(2013)bothreportedthatthecarbonfootprintofgrass‐finishedcattlewasgreaterthanforcalvesthatwereweanedandwentdirectlytothefeedlot.Thesedifferencesaredueinparttoslowerweightgainandlighterfinalbodyweightsandcarcassweightsofgrass‐fedcattlethancattlefinishedongrain‐andbyproduct‐baseddietsinthefeedlot.

MostLCAsassumethatcarbonsequestrationisminimalinestablished,unfertilizedpastures.Phetteplaceetal.(2001)andLiebigetal.(2010)suggestedtheremaybesomesmallnetcarbonsequestration,inestablishednativepastures.However,Liebigetal.(2010)notedthatfertilized,improvedpastureshadnetCO2‐eqemissions;primarilybecauseofincreasedlossesofN2Ofromfertilizernitrogen.Lupoetal.(2013)notedthattheassumedcarbonsequestrationofpastures(equilibriumvs.netsequestration)affectedthecarbonfootprintofgrass‐finishedcattle;however,regardlessofthecarbonsequestrationassumption,grass‐finishedcattlehadagreatercarbonfootprintthangrain‐finishedcattle.


5-14

Table5‐3:SummaryofSourcesandProposedGHGEstimationMethodsforAnimalProductionSystems

Section Source Method

AnimalProductionSystems,IncludingEntericFermentationandHousingEmissions5.3.1.2 DairyCattle Mits3equation; ASABEStandardD384.2andIPCCTier2(housing)5.3.2.2 BeefCattle ModifiedIPCCTier2 (entericandhousing);ASABEStandardD384.2

(housing)5.3.3.2 Sheep Howdenequationforgrazingsheep(Howden etal.,1994)andBlaxterand

Clapperton(1965)forfeedlotsheep5.3.4.2 Swine IPCCTier1 (entericmethane);ASABEStandardD384.2andIPCCTier2

(housing)5.3.5.2 Poultry IPCCTier1;ASABEStandardD384.2andIPCCTier2(housing)5.3.6.1 Goats IPCCTier15.3.6.2 AmericanBison,

Llamas,Alpacas,andManagedWildlife

IPCCTier1

ManureStorageandTreatmentTemporaryStack&Long‐TermStockpile5.4.1.2 Methane IPCCTier2usingU.S.EPAInventoryemissionfactors(EFs)anddiet

characterization5.4.1.4 NitrousOxide IPCCTier2usingU.S.‐basedEFsandmonthlydataComposting5.4.2.2 Methane IPCCTier2withmonthlydata5.4.2.4 NitrousOxide IPCCTier2AerobicLagoon5.4.3.2 Methane MethaneConversionFactor foraerobictreatmentisnegligibleandwas

designatedas0%inaccordancewithIPCC5.4.3.4 NitrousOxide IPCCTier2usingIPCCEFsAnaerobicLagoon,RunoffHoldingPond,StorageTanks5.4.4.2 Methane Sommermodelbasedon fractionsofvolatilesolids(Mølleretal.,2004)5.4.4.4 NitrousOxide FunctionoftheexposedsurfaceareaandU.S.‐basedemissionfactorsAnaerobicDigestion5.4.5.2 Methane IPCCTier2usingCleanDevelopmentMechanismEFsfordigestertypesto

estimateCH4leakagefromdigestersCombinedAerobicTreatmentSystems5.4.6.25.4.6.2

MethaneNitrousOxide

10%ofemissionsfromestimationofliquidmanurestorageandtreatment–anaerobiclagoon,runoffholdingpond,storagetanks

OtherTreatmentMethods5.4.7 Sand–Manure

SeparationNomethodprovidedbecause GHGemissionsarenegligible

5.4.8 NutrientRemoval Notestimatedduetolimitedquantitativeinformation5.4.9 SolidLiquid

SeparationNomethodprovidedbecause GHGemissionsarenegligible

5.4.10 ConstructedWetland Nomethodprovidedbecauseemissionsarenegligible;GHGsinksarenotedtolikelybegreaterthanemissions

5.4.11 Thermo‐chemicalConversion

NomethodprovidedasGHGemissionsarenegligible

5.1.4 OrganizationofChapter/Roadmap

Theremainderofthischapterisorganizedintofourprimarysections,asillustratedinFigure5‐2.Section5.2providesoverviewsofdairycattle,beefcattle,sheep,swine,andpoultryproduction


5-15

systemsandprovidesinformationondietandhousing.Section5.3providesthemethodsforestimatingGHGsfromhousing,primarilyfocusingonGHGsfromentericfermentation.MethodsarealsoprovidedforallthespeciesdescribedinSection5.2,plusadditionalanimaltypes(i.e.,goats,Americanbison,llamas,alpacas,andmanagedwildlife).Section5.4providesthemethodologyforestimatingemissionsfromdifferentmanuremanagementsystems.MethodologyisprovidedtoestimateCH4andN2Ofromtemporarystackandlong‐termstockpiles,composting,aerobiclagoons,anaerobiclagoons,andcombinedaerobictreatmentsystems.Section5.4alsoprovidesmethodsforestimatingCH4fromanaerobicdigestion.Aqualitativediscussionisprovidedforsand‐manureseparation,nutrientremoval,solid‐liquidseparation,constructedwetlands,orthermo‐chemicalconversion.Section5.5presentsresearchgapsforbothentericfermentationandmanuremanagement.

Therearefiveappendicestotheanimalproductionsystemschapterofthisreport.Appendix5‐AprovidesYmadjustmentfactorsforcalculatingentericCH4fromfeedlotcattle.Appendix5‐Bprovidesnutritionalinformationaboutanimalfeedstuffs(Ewan,1989;Preston,2013).Appendix5‐CdiscussesavailablemethodologiesforestimatingNH3emissionsfromanimalproductionsystems.Appendix5‐DdescribestheshapefactorsandrelatedequationsthatcanbeappliedinAppendix5‐Ctomoreaccuratelyestimateemissionsfrommanurestockpilesthatareshapeddifferently(assurfaceareapartiallydeterminesemissions).Appendix5‐Eprovidesadetailedreviewofmodelsevaluatedforsuitabilityforestimatingemissionsfromanimalproductionsystems.


5-16

Figure5‐2:AnimalProductionSystemsRoadMap


5-17


5-18

5.2 AnimalProductionSystems

Thissectionprovidesdiscussionontheproductionsystemsforbeefanddairycattle,sheep,swine,andpoultry.ThisprovidesthebackgroundnecessaryforunderstandingSection5.3,whichcoversGHGemissionsfromanimalproductionsystems.

5.2.1 DairyProductionSystems

5.2.1.1 OverviewofDairyProductionSystems

TheU.S.dairyproductionsystemiscomprisedofseveralkeyprocessesfordairycattle,theirmanure,andtheirendproducts(meat,dairy)asdepictedinFigure5‐3.Thisconceptualmodelprovidesanoverviewofthetypicaldairysystem,followingcattlefrombirthtoslaughterandfollowingmanurefromtheanimalthroughamanagementsystem.Manureisproducedduringeachstage,anddependingonthelocation,ismanageddifferently.ThemanagementoftheresultantmanurehasimplicationsonthequantityofGHGemissionsandsinks;thekeypracticesarediscussedindetailbelow.Theestimationmethodsinthischapterincludediscussionsforemissionsfromentericfermentation,housing,andmanuremanagementandarenotafullLCA.

TheU.S.dairyindustryiscomposedprimarilyoffourmajorsegmentsofproduction:1)calfrearing;2)replacementheifers;3)lactatingcows;and4)nonlactating(dry)cows.TheU.S.dairycattlepopulationin2012consistedofapproximately9.2millionmilkcowsandfirstcalfheifersandapproximately4.6millionreplacementheifers.ThemajorityofdairycattleintheUnitedStatesareHolstein(Holstein‐Friesian),followedbyJersey,withsmallernumbersofGuernsey,BrownSwiss,andAyrshire.Overthelast65yearstherehavebeendramaticincreasesinmilkproductionperanimal,duetochangesinherdmanagement,nutrition,composition,andbreedingprograms.Present‐daydairyherdsaredominatedbyHolsteincows(90percent)asopposedtoamixofthefivemostcommonbreeds(Jersey,Guernsey,Ayrshire,BrownSwiss,andHolstein)aswascommoninthe1940s.Withachangeinbreeddominanceandenhancedgenetics,thetypicalmilkproductionpercowhasincreasedfrom2,074to9,193kgofmilkperyear(Capperetal.,2009).

5.2.1.2 DietsforDairyCattle

Cowsinintensivedairyproductionsystemsarefeddietsthatreflectregionallyavailablefeedsandtypicallycontainbetween40and60percentconcentrates,suchasfeedgrains,proteinsupplements,andbyproductssuchasdistiller’sgrains.Typicaldietsincludecornsilage,alfalfaorgrasssilage,alfalfahay,groundorhigh‐moistureshelledcorn,soybeanmeal,fuzzywholecottonseed,andoftenbyproductfeeds(e.g.,corngluten,distiller’sgrains,soybeanhulls,citruspulp,beetpulp).Byproductfeedsmaymakeupalargeportionofthedietcomposition,providingkeynutrientsandameansofdisposalforotherwiselandfilledingredients.Proximitytocropprocessingplantsandindustriesmaydictatetheavailabilityofbyproductfeedsbyregion.

GrowingHeifersDietsforgrowingheifersareformulatedbasedongrowthrateandstageofrumendevelopment.Dietsrangefromliquiddiets(e.g.,milkormilkreplacer)innewborncalvestopelletedcompletefeedsinthegrowingcalf(e.g.,calfstarter)todietsthataresimilartothatofferedtolactatingcowsasthecowsgrowandrumensdevelop.Roughagecontentofthedietincreasesastherumendevelopswithhayorsilageoftenofferedinconjunctionwithacalfstarterduringatransitionperiod.Followingthattransition,typicalfeedsincludethoselistedabove.FeedsareoftenmixedtogetherinamixerandfedasaTotalMixedRation(TMR).Insomecases,feednotconsumedbythelactatingherdisfedtogrowingheiferswhentherumenisfullydeveloped(>9monthsofage).


5-19

Figure5‐3ConceptualModelofDairySystemsintheUnitedStates


5-20

LactatingCowsDietsforlactatingcowsareformulatedbytargetmilkproductionorstageoflactation,whichreflectsthedifferencesinenergyandproteinrequiredfordifferentamountsofmilkproduced.Peaklactationoccursabout60daysaftercalving,andproductionslowlydeclinesoverthenextseveralmonths.FeedstuffsarecommonlyblendedtogetherinamixerandfedasaTMR.

DryCowsDrycowdietsareoftenformulatedintotwostages:far‐offdryandclose‐updry.Duringthefar‐offdryperiod,cowsarefeddietswithhighforagecontent(>60%)usingingredientssimilartothatfedtothelactatingherd.Asdrycowsapproachcalving,energycontentofthedietincreasesbydecreasingforagetoincludemoreconcentratefeedsandmineralformulationchangesinordertoavoidpre‐andpost‐partummetabolicdisordersthatoftencenteraroundcalciummobilizationasthecowbeginstolactate.FeedstuffsarecommonlyblendedtogetherinamixerandfedasaTMR

5.2.1.3 DairyHousingandManureHandling

TwogeneraldairyfarmtypescanbedistinguishedintheUnitedStates:confinementfeedingsystems(includingbarnsanddry‐lots)andpasture‐basedsystems(USDA,2004a).Typicalhousingsystemsforconfinementfeedingoperationsincludetiestallbarns,freestallbarns,freestallbarnswithdrylotaccess,anddrylots.Drylotsystemsconsistofhousinganimalsinpenssimilartobeefcattlefeedlots,butatalowerstockingdensity.Inpasture‐basedsystems,cattlegrazepastureforperiodsoftime,basedonfeedavailabilityandenvironmentalconditions,andarehousedinbarnsandfedstoredfeedwhenpastureisnotavailable.Thedairycattlelifecycleproductionphaseisgenerallydividedintothreesegments:growinganimals(calvesandreplacementheifers),lactatingmaturecows,anddrymaturecows.Nutrientneeds,andthereforediets,andintakeareverydifferentbetweenthedifferentlifecyclephases:growingcattle(calvesandheifers),lactatingcows,anddrycows.Housingandmanuremanagementsystemsvaryconsiderablythroughoutthecountryandcandifferinaregionandbythesizeoftheherd.Incaseswherehousingandmanuremanagementvariesbyanimalgroup(e.g.,heifers,dry,andlactatingcows),estimatesofGHGemissionsfromonegrouparenotapplicabletoothergroups.Whenhousingandmanuremanagementaresimilarbetweengroups(e.g.,allcattleondry‐lots),dietandintakeadjustmentfactorscanbeusedtocompareGHGemissionsforthedifferentgroups.

Withtheexceptionofcalves,replacementheifersanddrycowsmaybehousedandmanagedinsimilarwaysaslactatingcows.Whenthisisthecase,muchofthediscussionisrelevanttothethreegroups.Incaseswherethelactatingherdismanagedinconfinementbutreplacementanddryanimalsaremanagedonpastureorindry‐lots,emissionsfromlactatingcattlearenotapplicablenotonlyduetodifferencesindietandintakebutalsoduetohousingdifferences.Therearenoreadilyavailablestudiesthathavefocusedstrictlyonemissionsfromdairycalfmanagementandhousing.Summarizedbelowarekeycharacteristicsofdifferenceinhousingbylifecyclephaseofadairycow.

Growing(calvesandreplacementheifers).Followingbirth,calvesareusuallyremovedfromthecowwithinafewhoursandaretypicallyrearedonmilkormilkreplacerincalfhutchesorbarnsforthreetosevenweeksuntilweaning.Femalecalves(replacementheifers)aretypicallymovedtogrouphousing(e.g.,superhutches,transitionbarns,openhousing,orpasture)untiltheyreachappropriatebreedingweightatabout14to15monthsofage.Somereplacementsarecontract‐rearedbyheifergrowersorsold.Followingbreeding,heifersareoftenraisedinlots,pasture,orbarnsuntiltheyarereadytocalve.Manureingrouphousingmaybehandledasasolid(beddedpackorcompostbarn)orasaslurry,similartothatdescribedbelowforlactatingcowsinfreestallbarns.


5-21

LactatingCows.Heiferstypicallyhavetheirfirstcalfatabout23to24monthsofage,afterwhichtheyjointheproductionherd.Acowtypicallyremainsintheherduntilaboutfiveyearsofage,althoughmanycowsarecapableofremainingproductiveintheherdfor12to15years.Eachperiodofproductionorlactationlastsfor11to14monthsorlongerandspansthetimeperiodfromcalvingtodry‐off,whichiswhenmilkingisterminatedabout40to60daysbeforethenextanticipatedcalving.Thus,cowsarebredwhiletheyareproducingmilk,usuallybeginningatabout60daysaftercalving,tomaintainayearlycalvingschedule.Followingthe35to60‐daydryperiod,thecowcalvesagain,andthelactationcyclebeginsanew.Cowsaverageabout2.8lactations,althoughmanyremainproductiveconsiderablylonger(Hareetal.,2006).

Lactatingcowsmaybehousedintiestall(stanchion)barns,whichlimitthecows’mobilitybecausethecowsaretethered,fed,andmilkedinthestalls.Agutterisusedtoremovethemanurebyabarncleaner,whichtypicallyplacesthemanuredirectlyintoamanurespreaderorinatemporarystoragepile.Freestallbarnsallowthecowstomovefreelyinandoutofstalls,andthecowsaremovedtoaseparatearea(milkingcenterorparlor)formilking.Manuretypicallyaccumulatesinalleywaysandisremovedviascraping,vacuuming,orflushingwitheithercleanorrecirculatedwater.Somefreestallbarnshaveslottedfloorswithlong‐termmanurestoragebelowthefloors.Manureisgenerallyworkednaturallythroughtheslotsbythecows’feetandwithassistanceviamechanicalscrapingequipment.Dairyfacilitiesmayalsousepasturesanddry‐lotstohouselactatingcows.Lotsarescrapedperiodically,asarepasturesoccasionally,andthesolidmanureiscollected.Althoughnotprevalent,somedairyfacilitiesmayhouselactatingcowsinbeddedpackorcompostbarns,againhandlingmanureasasolidmaterial.

DryCows.Muchlikegrowingcows,housingoptionsfordrycowsarethesameasdescribedaboveforlactatingcows.Thekeydeterminantismanagementpreferenceforthefarmownerand/orfacilityavailability.

Manureandsoiledbeddingfrombarnscanbehandledinanumberofways.Manurecanberemovedfromthebarnsmechanicallyanddirectlyloadedintomanurespreaders,althoughthisisnotcommononmediumandlargefarms.Manurecanalsobeprocessedinananaerobicdigesterwherebacteriacanbreakdownmanuretoproducebiogasthatcanbeflaredorcapturedforenergypurposespriortostorageofdigestereffluent.Whenmanurehasalowersolidscontent,itmaybestoredinatankorpitasaslurry,ortransportedtoasolid‐liquidseparationsystemwiththeliquidfractionconveyed(pumpedorbygravity)toalong‐termstoragepond,whilethesolidscanbedewaterednaturallyandreusedasbedding,composted,land‐applied,and/orsold.Indry‐lotsystems,themanureinthepensistypicallystackedandfollowingstorageiseitherland‐appliedorcomposted.Lotrunoffandmilkingparlorwashwaterispumpedtoastoragepond.Therearesomedry‐lotdairiesthatuseaflushsystemtocleanmanurefromalleywaysbehindthefeedbunks;thiswashwateriseventuallystoredinawastewaterpond.Openfreestalldairieshaveacombinationofbarnswithexerciseyardsbetweenthebarns,andthereforemanureishandledsimilarlyasinatraditionalfreestallbarnanddry‐lotproductionsystem.Wastewaterfrommilkingcenters(manure,clean‐in‐placewater,andfloorwashdownwater)istypicallycombinedwithbarnmanuredestinedforlong‐termstorage,andmaygothroughasolid‐liquidseparationprocessfirst.Inpasture‐basedsystems,manureisdepositeddirectlyontothepastureandthereforenotintensivelymanaged,butmayaccumulateinareaswhereanimalstendtocongregate(e.g.,wateringareas,shade).


5-22

5.2.2 BeefProductionSystems

5.2.2.1 OverviewofBeefProductionSystems

TheU.S.beefproductionsystemiscomprisedofseveralkeycomponentsforbeefcattle,theirwaste,andtheirendproducts,asdepictedinFigure5‐4.Thisconceptualmodelprovidesanoverviewofthetypicalbeefprocessingsystems,followingthesegmentsofthebeefcattleindustry(i.e.,cow‐calf,stocker,feeder/finisher,andpacker)frombirthtoslaughterandfollowingwastefromtheanimalthroughamanagementsystem.Wasteisproducedduringeachstageofactivityoccurringinthesystem,anddependingonthelocation,ismanageddifferently.

Ofthe90millionbeefcattleintheUnitedStates,approximately50millionarematurecowsandtheircalvesoncow‐calfoperations(USDANASS,2012),whichrangeinsizefromafewcowstoseveralthousandcows.Theseoperationsarenormallybasedonforages,eitherimprovedpasturesornativerange,andvaryinsizefromafewacrestohundredsofsections.Typically,whencalvesare150to220daysofagetheyareweanedandmovedtopastureforperiodsof60to200days(thestockerphase),althoughsomemaymovedirectlytoafeedlot.Thepasturesmaybenativerange,improvedperennialpastures,orannualssuchaswheatpasture,forage‐sorghums,andcropresiduessuchascornstalks.Afterthestockerphase,calvesnormallymovetofeedlotswheretheyarefedgrain‐andbyproduct‐baseddietsfor110to160days,untiltheyarereadyforharvest.Inaddition,steersandcullheifersfromdairyoperationsarealsofed.Approximately23millioncattlearefedinfeedlotsannuallyintheUnitedStates.Feedlotsrangeinsizefromafewhundredheadtomorethan100,000headcapacity.

5.2.2.2 DietInformationforBeefCattle

Cow‐CalfandBullsGrazingpasturesmaybenativerange,improvedperennialpastures,orannualssuchaswheatpasture,forage‐sorghums,andcropresiduessuchascornstalks.Beefcowsandbullsaretypicallyfedsupplementalfeedsduringtimeswhenpastureorrangeforagedoesnotmeettheirnutritionalrequirements,usuallyinwinter.Arecentsurveyofthebeefcow‐calfindustryfoundthat74percentofoperationsfedaproteinsupplementand51percentfedanenergysupplement(USDA,2010).Overallproteinwassupplementedforanaverageof173days(SE=9.6)andenergyfor162days(SE=12.7),butthiswashighlyvariableacrossregionsofthecountry.Ninety‐sevenpercentofoperationsinthesurveysupplementedthecowherdwithroughageforanaverageof154days(SE=7.0).Theproteinsupplementswerereportedasplantproteinorurea‐based.Cornwasreportedastheprimaryenergysupplement.Theamountofsupplementfedperheadperdaywasnotincludedinthereport.

StockersStockersgrazeforage,includingwheatpasture,improvedpastures,range,andcropresidues.Stockercattlemayalsoreceivesupplementalproteinorenergyfeedstoincreaseperformanceand/orextendpastureforage.Supplementsmayormaynotcontainanionophore.Somestockercalvesmaybeimplantedwithagrowthpromotingimplant;othersarenot.


5-23

Figure5‐4ConceptualModelofBeefProductionSystemsintheUnitedStates


5-24

FeedlotCattletypicallyenterfeedyardsbetweentheagesof100and350daysweighing200to350kg,andgotoslaughterweighingbetween500to700kg.Theyarefedhigh‐concentrateorhigh‐byproductdietsfor100to200days.Ofthecattlefed,approximately55percentarebeefsteers,25to30percentarebeefheifers,and12to20percentaredairysteersandheifers.ThevastmajorityofcattlefedarebeefbreedsofBritishorContinentalbreeding.However,manycattlewithBrahmangeneticsarealsofed,mostlyinthesouthernplains.Inareaswithasignificantdairyindustry,steersandheifersofdairybreeding(mostlyHolstein)arealsofed.

Typicalfeedlotdietscontainhighconcentrationsofgrain(75percentormore)and/orbyproductssuchasdistillersgrainsandglutenfeed.Theyarenormallybalancedforprotein,energy,vitamins,andminerals(VasconcelosandGalyean,2007).Becausemanybyproductscontainhighconcentrationsofproteinandmineralssuchasphosphorusandsulfur,whenthesebyproductsarefed,dietaryconcentrationsofproteinandsomemineralsmayexceedanimalrequirements.FeedingofionophoressuchasmonensiniscommonintheUnitedStates,asistheuseofgrowth‐promotingimplants.Thedietsfedinfeedyardstendtodifferbetweenthenorthernandsouthernplains.Finishingdietsbasedondry‐rolledcorn(DRC)andhigh‐moisturecorn(HMC)dominateintheNorth,whereasdietsbasedonsteam‐flakedcorn(SFC)dominateintheSouth.Theuseofbioethanolco‐productssuchasdistiller’sgrainsandcorn‐millingco‐productssuchascornglutenfeedinfinishingdietsisgreaterinthenorthernplainsbecauseofthegreateravailabilityoftheseco‐products,buttheiruseisincreasinginthesouthernplains.

5.2.2.3 BeefCattleHousingandManureHandling

Cow‐CalfandBullsCowherdsandreplacementheifersaremostoftenhousedonpasture.Fecesandurinearedepositedonpasturesandrangelandandmaybeconcentratedinareasinwhichfeedingorwateringtakesplace.

StockersStockersareusuallyhousedonpastureandthusnomanurehandlingisusedandGHGemissionsareapartofthecroplandssection(seeChapter3,QuantifyingGreenhouseGasSourcesandSinksinCroplandandGrazingLandSystems).Calvestobeusedasstockerscanbehousedforshortperiodsoftimeindry‐lots.

FeedlotHousingandmanuremanagementatmostbeefcattlefeedingoperationsdiffergreatlyfromthoseusedinotherlivestockspecies,withthevastmajoritybeingfinishedindry‐lotpenswithsoilsurfaces.Manureisnormallydepositedonthepensurfaceandscrapedfromthepensaftereachgroupofcattlegoestomarket.Partofthemanuremaybestackedinthepentoprovidemoundsthatimprovependrainageandassurethatcattlehaveadryplacetolieafterrains.Manureremovedfromthepenmaybeimmediatelyappliedtofieldsnearthefeedlot,stockpiledforlateruse,orcompostedinwindrows.Manurescrapedfromthepensnormallyhasamoisturecontentof30to50percentandmaycontainsomesoilfromthepen.Becausethemanuremayremaininthepenorinstockpilesforseveralmonthsbeforeitisappliedtothefield,aportionofthenitrogenandcarbonmaybelostbeforethemanureiscollectedorappliedtoland.Runofffrompensisnormallycollectedinretentionponds.Settlingbasinsmaybeusedtolimitthequantityofmanuresolidsandsoilparticlesthatreachtheretentionpond.

IntheNorthernUnitedStates,andinareaswithhighrainfall,cattlemaybefedinnaturallyventilatedbarnswithslottedfloorsforcollectionofurineandfecesorindeep‐beddedbarnswithconcretefloorsinwhichthemanureandbedding(normallystraworstalks)areallowedto


5-25

accumulateduringthefeedingperiod(Spiehsetal.,2011).Addingbeddingwillincreasethequantityofcarbon(andpossiblynitrogen)availabletobemetabolizedbymicrobesinthepen.Thesefacilitiesarecharacterizedbytheabsenceofrunoffcontrolsystems.

5.2.3 SheepProductionSystems

5.2.3.1 OverviewofSheepProductionSystems

Thereare81,000sheepandlamboperationsintheUnitedStates,withaninventoryof5.53millionsheepandlambsasofJanuary1,2011(USDANASS,2011).Mostbreedingflocksaresmallandconsistoflessthan100headofewes.Thelambfeedingindustryisalsodiverseinsize,withsmallfeedlotslocatedthroughoutthefarmflockareasandlargefeedingoperationslocatedincloseproximitytolocalgrainproductioncapacity(Shiflett,2011).

5.2.3.2 Diets,Housing,andManureHandlingforSheep

Lambingseasonmayoccuratvarioustimesduringtheyear,dependingonproductionobjectives,feedresources,environmentalconditions,andmarkettargets.Whenlambingoccurs,JanuarythroughMarch,ewesaregenerallyhousedinbeddedbarns.Beddingisremovedandspreadafteranimalsareturnedoutonpasture.EwesaregenerallybredonpastureinSeptemberthroughNovemberand,dependingonweather,willbemovedintobarnspriortolambing—orearlierasforageavailabilityandweatherdictate.Dietsconsistofpastureorgrazingcropresiduefromspringturnoutthroughearly‐andmid‐gestation.Whengrazedforageisnolongeravailable,ewesarehousedormovedtodry‐lotsandfedhayand/orhayandgraindietsasgestationrequirementsdictate.Theprimaryforagesourceisalfalfa,andcornisthepredominantgrain.Dietsrangefrom100percenthayto60:40percentforage:concentratewhilelactating.Mostlambsareweanedatapproximately90daysand41kgandsenttofeedlotsforfinishing.

Pasturelambingisanotherfarmflockproductionsystemthatisusedtomaximizenutrientsprovidedbygrazedforages.InthiscasetheeweisbredinNovemberorDecembertolambonpastureinAprilorMay.Lambsareweanedatapproximately120daysand32kgandmaybesenttothefeedlotorfinishedongrass.Ewesarenotfedgrain,andharvestedforageisprovidedonlywhengrowingseasonsandweatherdictate.Theseflockswillbehousedinbeddedbarnsinareasrequiringprotectionfromwinterweatherconditions.RangeproductionsystemsincludelambinginAprilorMay,wheremost(andinsomecasesall)dietsareprovidedbygrazedforages.Supplementationwithharvestedfeedsorgrainsisusuallyinresponsetounpredictableweatherandenvironmentalconditions.

Mostlambsarefinishedinfeedlotsandfeddietscontaining85to90percentgrain.Lengthoffeedingperiodswillrangefromweekstomonthsdependingonin‐weightsandtimerequiredtoreachfinalweight(industryaveragefinalweight=61kg).Sheepfeedlotsareprimarilydry‐lots,andmanureisscrapedfromthepenssimilarlytobeefcattlefeedlots.

5.2.4 SwineProductionSystems

5.2.4.1 OverviewofSwineProductionSystems

Theconceptualmodel(Figure5‐5)oftheU.S.swineproductionsystemprovidesanoverviewoftypicalproductionsystems,followinganimalsfrombirthtoharvestandfollowingmanurefromtheanimalthroughamanagementsystem.Manureisproducedduringeachstageofproductionoccurringinthesystem,anddependingonthelocation,ismanageddifferently.ThishasimplicationsonthequantityofGHGemissionsandsinks,someofwhicharediscussedindetailintheemissionsdiscussionsection(Section5.3.4).


5-26

Figure5‐5:ConceptualModelofSwineProductionSystemsintheUnitedStates


5-27

SwineproductionintheUnitedStatesremainsimportanttoboththenation’sdietandeconomy(Davies,2011),withsignificantlevelsofconsumption,imports,andexports.AccordingtotheU.S.DepartmentofAgriculture’sNationalAgriculturalStatisticsService,the2011populationwasnearly66millionhead(USDANASS,2012).

Swinearepredominantlygrownwithproductionofporkoccurringinatwo‐stageorthree‐stagesystem:

Stage1:Sowoperation,pigletsleaveatweaning. Stage2(optional):Nurseryoperation,weaning(10daysofage/17lbs)to42daysofage/45

lbs. Stage3:Severaloptions:

− Afinishingoperation(16‐weekproductionsitewherepigletsaredeliveredfromanurserysiteatapproximately42daysofage/45lbsandstayuntil154daysofage(22weeks)or

− Awean‐to‐finishoperation(24‐weekproductionsitewherepigsaredeliveredatweaningdirectlyfromasowoperation(10daysofage/17lbs)andstayuntil178daysofage(25.5weeks)).

Themanuremanagementsystemsassociatedwiththeseproductionoperationsallhavethebasicelementsofcollection,storage,treatment,transport,andutilization.Mostswinefacilitieshandlemanureasaslurryeitherwithinthebuilding(deeppitfinishingbarnsorshallowpitnursery,gestationorfinishingbarns)orinoutsidestorage(pull‐plugsystemsfornurseries,sows,orfinishingpigs).Collectionandstorageisgenerallyaccomplishedbystorageofthewasteunderthefacility,dischargetoaseparatestoragetank,orflushingtoananaerobiclagoon.Inthecaseofin‐housemanurestorage,littlewaterisaddedtothestoragestructure,andanaerobicconditionsprevailwithlittlebiologicalprocessingofmanuretakingplace.Outsidestoragestructuresthatcontainslurrywithlittledilutionwaterofferminimalbiologicaltreatmentaswell.However,lagoonsystemswheremanureisflushedfromhousingandadditionaldilutionwaterisaddedoffermoretreatment.Drysystemsordeep‐beddedsystemsexisttoamuchlesserextent,primarilyforsoworfinishingproduction.Inthesecasesbeddingmaterial,oftenstraw,isprovidedandmanureplusbeddingishandledassolidmaterial,sometimescomposted.

IntheMidwest,thesystemofmovingstoredswinewastetocropfieldsiswelldefinedandunderstood(HatfieldandPfeiffer,2005;Maloneetal.,2007;Jareckietal.,2008;Vanottietal.,2008;BrooksandMcLaughlin,2009;Jareckietal.,2009;Agnewetal.,2010;Cambardellaetal.,2010;Lovanhetal.,2010).Yetthesesystemscontinuetoevolvetoaddressbotholdandnewissues,suchasfrozenground,applicationtiming,andemissionsassociatedwithsoilapplicationvianewequipment.AllofthemanuremanagementsystemsresultinGHGemissions,buttheyvaryintermsofpointandnon‐pointsources.

5.2.4.2 DietInformationforSwine

Theswineindustryfeedsprimarilyacorn‐soybeanmealbaseddiet.Drieddistillersgrainswithsolubles(DDGS)areoftenfedtobothsowsandfinishingpigsand,asavailabilityofthisfeedincreases,theamountfedincreasestoasmuchas40percentofdietdrymatterintake(DMI).Similarly,whensyntheticaminoacidsourcespricecompetitivelywithfeedproteinsources,thenumberofsyntheticaminoacidsincludedinfinishingpigdietsincreases.Two(lysineandmethionine)ormore(threonine,perhapstryptophan)syntheticaminoacidsarefedcommonlytodaywiththebenefitofreducingtotalnitrogenfed,andthereforeexcreted,byswine.


5-28

5.2.4.3 SwineHousingandManureHandling

Mostcommercially‐raisedfinishingswinearehousedindoorstoprovideabiosecureenvironmentandreducediseasepressures.Manureishandledasslurrywithlittleornobeddingaddedtothesystemandminimaladditionofwater.Asmallbutgrowingportionofthecommercialswineindustryhousebothfinishingpigsandsowsinhoopbarns.Inthesecases,beddingmaterial,oftenstraw,isprovided,andmanureplusbeddingishandledassolidmaterial.

5.2.5 PoultryProductionSystems

5.2.5.1 OverviewofPoultryProductionSystems

TheU.S.poultryproductionsystemiscomprisedofseveralkeyprocessesforpoultry,theirmanure/litter,andtheirendproducts(meat,eggs)asdepictedinFigure5‐6.

Thefigureprovidesanoverviewofthetypicalproductionsystems,followingboththelayerandbroilerphases.Thisconceptualmodelprovidesanoverviewofthetypicalpoultryproductionsystems,followingbirdsfrombirthtoslaughterandfollowingmanurefromtheanimalthroughamanagementsystem.Manureisproducedduringeachstageofactivitiesoccurringinthesystem,anddependingonthelocation,ismanageddifferently.TheemissionsfrommanuremanagementarediscussedindetailinSection5.3.

TheU.S.poultryindustryistheworld'slargestproducerandsecondlargestexporterofpoultrymeat.TheU.S.isalsoamajoreggproducer.Thepoultryandeggindustryisamajorfeedgrainuser,accountingforapproximately45.4billionkg(100billionlbs)offeedyearly.

Theeggincubationperiodforachickenis21days.Followinghatch,broilerchickensarerearedfor42to49days(sixtosevenflocksperyear),dependinguponthemarketintent(e.g.,roasters).U.S.eggoperationsproducemorethan90billioneggsannually.Morethan75percentofeggproductionisforhumanconsumption(thetable‐eggmarket).Theremainderofproductionisforthehatchingmarket.Theseeggsarehatchedtoprovidereplacementbirdsfortheegg‐layingflocksandtoproducebroilerchicksforgrow‐outoperations.Followinga16to22weekgrowthperiod,hensstartlayingeggs.

TheU.S.turkeyindustryproducesmorethanone‐quarterofabillionbirdsannually,withtheliveweightofeachbirdaveragingmorethan25lbs.Theeggincubationperiodforaturkeyis28days.Followinghatch,turkeypoultsarerearedfor15to22weeks(onetothreeflocksperyear)dependingonthemarketintent(e.g.,roasters).

5.2.5.2 DietandGrowthInformationforPoultry

Dietsformeatbirdsconsistlargelyofcornandsoybeanmeal(commonly85to92percentofthediet);however,alternateingredientssuchasdrieddistillersgrainswithsolubles(DDGS)andotherco‐products,andsyntheticaminoacidsareincreasinglyused.Hendietsaremostcommonlycomposedofcornandsoybeanmeal.Otheringredients,suchasDDGS,maybeincluded(rarelymorethan20percentofthediet).Ingredientvariabilityislargelyinsourcesofsupplementalenergy,minerals,andadditivestoimproveanimalhealthandperformance.Dietsareformulatedbasedongrowthrateandeggproductionandfedaseitheramashorapellet.Bonestrengthisanimportantcharacteristicofmeatbirdqualitythereforeprovisionofmineralssuchascalciumandphosphorusarecarefullyconsideredwhendietsareformulated.Similarly,eggshellqualityiskeyforlayinghens,andasaresult,calciumutilizationisakeyelementindietformulation.


5-29

Figure5‐6:ConceptualModelofPoultryProductionSystemsintheUnitedStates


5-30

Poultrybreedschangerapidly,demonstratingimprovedproductionefficiency,andassuch,dietsareincreasinglydensewithenergyandprotein.Thesechangesareduetoacombinationofgeneticsandmanagement,includingdietformulation.2WhiledietandgeneticinfluenceswereconsideredinastudybyHavensteinetal.(2007),theresultssuggestthatthedietchangesthatoccurredbetween1966and2003interactedwithotherfactors(flockage,ambienttemperature)toinfluencebirdgrowth.Someestimatethat85percentoftheimprovementinthegrowthrateofbroilerchickensisattributabletogenetics(Havensteinetal.,2003).3

IntheUnitedStatesthereisnoban,atpresent,onuseofantibioticgrowthpromoters(AGPs)inpoultryproduction(meatbirds).However,thetrendistowardconsumerswantingproductsthathavenotusedAGP.FindingreplacementsforAGPwilllikelyinvolvetheuseofmultipleproductsinthediet,eachwithsomeofthebenefitsofAGP,andmanagementchangeswillplayakeyroleinmaintaininganimalproductivityintheirabsence.Itisunlikelythatasinglereplacementwillbefoundthatwillprovetobeeconomicallyviable(DibnerandRichards,2005).

5.2.5.3 PoultryHousingandManureHandling

Thevastmajorityoftheindustryraisesbirdsonlitterinmechanicallyventilatedornaturallyventilatedhouses.Reuseoflitterandnumberofflocksgrownonthesamelitterisvariableacrossthecountry,andcanrangefromaslowasasingleflocktoasmanyas18flocksonthesamelittersource.Litterdrymattercontentcanvaryfrom40to80percent,dependingonmanagement.

Layinghenandpullethousingtypesrangefromhigh‐risehouseswherehensareincagesandmanureaccumulatesinabasementunderthecagesandisremovedannually,toamanure‐belthousewherehensareincagesandmanureisremoveddailyormorefrequentlyfromthebasementtoanexternalshedandstackedbeforeperiodicremovalforlandapplication(onceortwiceperyear),toaviarieswherehensareraisedonlitter(inlargeroomsasopposedtocages)thatisremovedfromtheaviaryannuallyormorefrequently.Whenmanureisremovedfromthehouseitmaybeimmediatelyappliedtofields,stockpiled,orcomposted.Moisturecontentmayvaryfrom80percentmoisturedownto20percentmoisture(aviaries).

5.3 EmissionsfromEntericFermentationandHousing

Emissionsfromanimalproductionsystemsincludethosefrombothentericfermentationandfromanimalhousing(includinganimalmanureinhousingareasthatmayultimatelybeflushedorscrapedandthentransportedtoanexternalmanuremanagementsystem).TheproductionofGHGsinlivestocksystemsoriginatesfromavarietyofsources,includingdirectlyfromtheanimalsthemselves;manureinlotsandbarns;stockpiledandcompostingmanures;manureslurriesorwatersintanks,pits,lagoons,retentionponds,settlingcells,etc.;andfromsoilsaftermanureapplication.Emissionsfromthesesourcesdependonanimalsizeandage,diet,manureproduction,handlingandstoragesystem,lotsurfaceandsoilcharacteristics,andambientweatherconditions(i.e.,temperature,wind,humidity,andprecipitation).Foreachanimaltype,thissectionsummarizes2Havensteinetal.(2007)compared1966strainsto2003strainsandobserveda20percentbettercumulativefeedconversionratiointhe2003tomturkeyfeda2003dietrelativetoa1966tomfedadiettypicalof1966.Feedefficiencyto11kgbodyweightwasapproximately50percentbetter(2.13at98daysofagein2003toms,comparedwith4.21at196daysfor1966toms).

3Havensteinetal.(2003)comparedthe1957Athens‐CanadianRandombredControlstrainandthe2001Ross308strainofbroilerswhenfedrepresentative1957and2001diets.The42‐dayfeedconversionsfortheRoss308birdsfedthe2001and1957feedswere1.62and1.92,respectively(withaveragebodyweightof2,672and2,126g).The42‐dayfeedconversionsfortheAthens‐CanadianRandombredControlwere2.14and2.34(averagebodyweightof578and539g,respectively).


5-31

thecurrentunderstandingofentericfermentationandlivestockhousingemissionsandpresentsrecommendedmodelsforestimatingsuchemissions,includingtherationaleforselectingmethods.

ActualfieldmeasurementsofGHGsfromentericfermentationoverthepastseveraldecadeshavebeeninstrumentalinimprovingourunderstandingoftheunderlyingscienceandtheresultingmodelspresentedinthissection.Fordairyanimals,mostoftheemissionsestimatesavailablerepresentthelactatinganimal.Theequationsforgrowingbeefanimalsarelikelyappropriateforgrowingdairyanimalsifdietcompositionisconsidered.Thetextboxesonthefollowingpagessummarizeseveralofthekeytechniquesthathavebeenusedinmeasurementstudiesforbothindividualanimalsandgroupsofanimals.FurtherstudiesofthistypewillbeneededtoaddressresearchgapsinSection5.5.

ThissectionprovidestherecommendedmethodforestimatingGHGsfromentericfermentationandapplicablehousingemissions.Quantitativemethodsareprovidedfordairy,beef,sheep,swine,poultry,andotheranimals(i.e.,goats,Americanbison,llama,alpacas,andmanagedwildlife).Foreachsection,backgroundinformationisprovidedontherangeofemissionsandexistingmodelsforestimatingemissionsandtherationaleforthemethodselected.Forestimatingemissionsfromentericfermentation,theactivitydataisthesameforallanimaltypes.Ancillarydataincludesthepropertiesofthediets(e.g.,crudeprotein(CP),digestibleenergy(DE),neutraldetergentfiber(NDF)).Forsimplicity,activitydataandancillarydataarelistedinTable5‐2andarenotrepeatedbelowforeachanimaltype.

5.3.1 EntericFermentationandHousingEmissionsfromDairyProductionSystems

Althoughthedairyindustryisprimarilycomposedofthreelivestocktypes[growing(i.e.,calves,replacementheifers),lactatingcows,anddrycows],mostofthelimitedemissionsresearchconductedtodatehasbeentargetedatlactatingcows,whichtypicallyproduceatleast50percentmoreentericCH4perheadthanotherdairycattle.Fewemissionsdataexistforcalves,heifers,anddrycows.Therefore,thediscussionherefocusesprimarilyonlactatingcows.

Dataneededtoestimateemissionsincludehousingsystem(pasture,barntype,dry‐lot),animalcharacteristics(breed,bodyweight,growthpotential,stageoflactation,milkingfrequency,andmilkproduction)andpopulation,dietaryinformation(DMI,dietaryCP—alsoNDF,fat,DE,metabolizableenergy(ME),netenergy(NE),nutrientexcretion(N,C,andvolatilesolids),useofrecombinantbovinesomatotropin,useofmonensin,typeofmanurehandlingsystem,frequencyofmanureremoval,typeofbedding,andmanurecharacteristics(totalammoniumnitrogen,pH).

EntericFermentationEntericCH4productionvarieswithproductionstageindairycattle,withthehighestratesbeingproducedbylactatingcows(Table5‐4).Thistableillustrates,conceptually,theobservedvariationincattleatdifferentstagesofmaturityandactivity,butitisnotintendedtoprovideadepictionofabsolutedifferences.TherearemanyfactorsthataffectentericCH4production,andthereforealteringdairycattledietscouldhaveanimpactonentericCH4production.Foranin‐depthdiscussionofdietaryeffectsonentericCH4production,seeSection5.3.7(FactorsAffectingEntericFermentationEmissions).However,theresultsinTable5‐4clearlyillustratethedifferenceinentericemissions;inparticular,emissionsfromdairycattlearerelativelyhigherthanthosefromgrowing(i.e.,heifers)anddrycattle.

Table5‐4:ExamplesofCH4EmissionsMeasuredinDairyCattle

AnimalType CH4EmissionMethodUsedto

MeasureEmissions Reference

Dairycattle 260ganimal‐1day‐1CalculatedBlaxterandClapperton Crutzenetal.(1986)


5-32

AnimalType CH4EmissionMethodUsedto

MeasureEmissionsReference

Heifer6‐24month 140gLU‐1day‐1 SeeaboveDairycattle,dryperiod 139gLU‐1day‐1 Respirationcalorimetry

Holter&Young(1992)Dairycattle,lactating 268gLU‐1day‐1 Seeabove

Dairycattle 257gLU‐1day‐1 Respirationcalorimetry Kirchgessneretal.(1991)

Dairycattle,lactating 429ganimal‐1 day‐1 WindtunnelSunetal.(2008)

Dairycattle,dryperiod 290ganimal‐1 day‐1 WindtunnelDairycattle,lactating 538–648ganimal‐1day‐1 Respirationcalorimetry Aguerreetal.(2011)LU,livestockunit=500kg

MethodsforMeasuringCH4 EmissionsfromEntericFermentation

IndividualAnimalsThestandardmethodofmeasuringCH4emissionsfromruminantsisbyrespirationcalorimetrychambers.Othertechniques,includingheadboxes,internaltracers,micrometeorology,isotopedilution,andpolyethylenetunnels,havebeenused(Kebreabetal.,2006;Harperetal.,2011).Severalnewtechnologieshavebeendevelopedtomeasureindividualanimalemissions.ToaddressthedifficultyinmeasuringentericCH4frommanyanimalsonpasture,alternatemethodsaresought.Asoneexample,Goopyetal.(2011)hasproposedaportablestaticchambermethodtomeasuredailyCH4production.Untilvalidated,resultsusingalternatemethodsshouldbeviewedwithcaution.

AvarietyofrespirationchambershavebeendevelopedtomeasureentericCH4lossesand/ortotalenergymetabolismoftheanimal.Ingeneral,airispulledfromthechamberataknownrateandreplacedwithoutsideair.FlowofairandconcentrationsofCH4,CO2,andoxygen(O2)intheairenteringandleavingthechamberaremeasuredtodeterminetotalCO2andCH4productionandO2consumption.Whenproperlycalibratedandused,respirationchambersgivehighlyaccurate,precisemeasurements.However,theyareexpensivetobuildandoperate,andrequiresignificantknowledge,skill,andlabor.

Feedintakeandproductionareusuallydepressedinanimalsinchambersandthemeasurementsdonotnecessarilyreflectintakeandproductionfromtypicalcommercialoperations.Thislimitationcanbepartiallyovercomebyfeedinganimalsatdifferentlevelsofintakeandmeasuringtheeffectsofintakelevel.Headboxesusethesameprinciplesasrespirationcalorimetry,andhavemanyofthesamelimitations.In‐barnchambersusingdrop‐downcurtainshavebeenusedtomeasure,atrelativelylowcost,emissionsofNH3,CH4,andothergassesfromgroupsofdairycows(Powelletal.,2007;Powelletal.,2008;Aguerreetal.,2011).

Internaltracertechniquessuchasthesulfurhexafluoride(SF6)tracermethod(Johnsonetal.,1994)weredevelopedtoallowmeasurementsfromfree‐ranginganimals,suchasthosemanagedunderpasturesituations,orwhenreal‐worldlevelsoffeedintakeareneeded.Thelimitationstothismethodaretheneedfortrainedanimals,theneedforlargersamplesizes(comparedwithchambers)todetecttheinfluenceofmitigationtechniques,andconcernsaboutinconsistentreleasesoftracergasfromSF6permeationtubesmanufacturedforlargereleaserates.Additionally,theSF6techniquegenerallyresultsinemissionestimatesthatarelowerthanchambermeasurements;possiblybecausetheSF6methoddoesnotmeasurealllowergutCH4production(McGinnetal.,2006).TheadvantagesandshortcomingsoftheSF6methodhavebeenrecentlyreviewed(Lasseyetal.,2011).


5-33

Methods for Measuring CH4 Emissions from Enteric Fermentation

Group of Animals

MicrometeorologymethodshavebeenusedextensivelytomeasureCH4andNH3emissionsfrompastures,wholefeedyards,orportionsofthefeedyard(pens,retentionponds,manurestockpiles,etc.).Thesemethodshavebeenreviewed(Fowleretal.,2001;Fleschetal.,2005;Harperetal.,2011).Laubacketal.(2008)comparedtheSF6methodwiththreemicrometeorologicalmethods(integratedhorizontalflux,fluxgradient,andbackwardLagrangianstochastic(bLS))usingsteersgrazingpaddocks.Ingeneral,themicrometeorologicalmethodsgavehigherCH4measurementsthantheSF6method,withthedifferencebeinggreaterwhenanimalswerewithin22metersoftheCH4sampler.Thiseffectwasespeciallytrueforthefluxgradientmethod.ThelowervaluesfortheSF6methodcouldbedueinparttothefactthattheSF6methoddoesnotmeasureemissionsfromthelowergutorfromfermentationoffecesonthepaddocksurface.

Tomkinsetal.(2011)comparedentericCH4emissionsofsteersonpastureusingthebLSmethodandrespirationchambers.EmissionsestimatedusingthebLSmodelwereslightlygreaterthanwithrespirationchambers(136.1vs.114.3gheaddaily‐1).HoweveremissionspergramofDMIweresimilar(29.7vs.30.1gCH4kgDMI‐1,respectively),suggestingthatthebLSmodelmaybesuitableforestimatingentericemissions.

Mostdispersionmodelsandmicrometeorologicalmethodsassumethatemissionsareuniformlydistributedoverthesourcearea.Insomecases,suchasforindividualcattleinapenorfield,thisisnottrue.Therefore,McGinnetal.(2011)developedamethodthatusedapoint‐sourcedispersionmodelandatmosphericCH4concentrationsmeasuredusingmultipleopen‐pathlaserstomeasureCH4emissionsfromapaddockcontaining18cattle.MeasuredentericCH4emissionsweresimilartovaluesmeasuredusingothertechniques.However,recoveriesofknownCH4releasesaveragedonly77percentusingthismethod.Themethodgavemorereliablemeasurementsduringthedaytimewhenatmosphericconditionswereunstablethanatnightwhenatmosphericconditionswerestable.

Methods for Measuring Emissions from Manure

Estimatingemissionsfromlargeopensourceareastypicallyassociatedwithbothdairyandbeefcattleproductionisverychallenging,duetotheinabilitytocontainandmeasurethesourcearea.Instrumentsandtechniquestomeasureambientatmosphericgasesfromtheselargesourceareas(i.e.,dry‐lotbeefanddairycattleyards,freestalldairieswithnaturallyventilatedcurtainsidewallbarns,andgrazingland)mustbeabletodetectlowerconcentrationsthanthoseencounteredintypicalenclosedconfinedanimalproductionsystems,becauseofthelowconcentrationsandhighvariabilityresultingfromhighandvariableventilationrates.Alargerchallengewithmeasuringemissionsfromopenfacilitiesistheabilitytoestimateairflowduetothelackofadefined,constantairinletandairoutlet.ReportedbackgroundNH3concentrationstypicallyrangefrom<1.3to53.3partsperbillion(ppb)(Toddetal.,2005),backgroundatmosphericN2Oconcentrationsnearfeedyardsaverageabout319ppb(Michaletal.,2010),andbackgroundCH4concentrationstypicallyrunintheareaof1,780ppb(Michaletal.,2010).


5-34

Methods for Measuring Emissions from Manure (Continued)

NumerousfactorscanaffectatmosphericconcentrationsofNH3andGHGnearlivestockoperationsincludingsamplingheight,atmosphericstability,windspeed,backgroundconcentrations,stockingdensity,samplingsite,samplingtime,temperature,andwinddirection(fetch).AveragedailyNH3concentrationsmeasuredatavarietyofsimilarsourceareasrangedfromapproximately100to2,000µgm‐3.Measuredmaximumconcentrationsrarelyexceed2,000µgm‐3.Ammoniaconcentrationsdecreaserapidlydownwindofsourceareas(Miner,1975),approachingbackgroundconcentrationsinlessthan800meters(McGinnetal.,2003;Sweeten,2004).

AtmosphericCH4concentrationsmeasuredatfeedlotsanddrylotdairieshaverangedfrom3.3to4.7partspermillion(ppm)(Michaletal.,2010),andfrombackground(approximately1.78ppm)to6.20ppm(Bjornebergetal.,2009),respectively.Nitrousoxideconcentrationsmeasuredatfeedlotsrangedfrom319ppb(background)to443ppbandaveraged396±16ppb(Michaletal.,2010).Nitrousoxideconcentrationswerehighestfollowingarainfallevent.Afterarain,CH4concentrationsaveraged3.7±0.1ppm.Atdry‐lotdairies,medianN2Oconcentrationsrangedfrom314ppbto330ppb,whichareveryclosetoglobalbackgroundvalues(Bjornebergetal.,2009).

SmallfluxchambersandwindtunnelshavebeenusedtoestimateemissionsofNH3,CH4,andN2Ofromfarmlands,pastures,pensurfaces,lagoons,andretentionponds(HutchinsonandMosier,1981;Ventereaetal.,2009;Venterea,2010;Harperetal.,2011;Hristovetal.,2011).Ingeneral,chambersalterthemicroenvironmentofthesurfaceandmayalteremissions.Thus,theaccuracyofthesemethodsfordeterminingemissionfactorsforsomegases(especiallyNH3)hasbeenquestioned(GaoandYates,1998;Harper,2005;Ventereaetal.,2009;Parkeretal.,2010;Venterea,2010;Harperetal.,2011).MeasuresofNH3emissionsusingfluxchambersandwindtunnelsarehighlydependentuponairflowandairturnoverratesinthechamber(Coleetal.,2007b;Parkeretal.,2010).Basedontheconventionaltwo‐filmmodelusedtodescribevolatilizationfromasolute‐solventmixture(Parkeretal.,2010),manygaseousemissionsarecontrolledbythegasfilmabovetheliquidortheupperportionoftheliquid(liquidfilm)definedbytheHenry’slawconstant.Ifvolatilizationisinhibitedbyhighconcentrationsinthegasphase(i.e.,gas‐filmcontrolled),increasesingaseousconcentration—suchaswithfluxchambers—willleadtosignificantunderestimationoftrueflux.Venterea(2010)reportedthatemissionsofN2Oestimatedusingstaticchamberswereunderestimatedbyapproximatelythreeto38percent,dependinguponsoilwatercontent,typeofregressionperformed(linearvs.quadraticvs.nonlinear),andotherfactors.Thepercentageofunderestimationtendedtobegreaterwithdrysoils,probablybecauseN2Ofluxislowerwhensoilsaredry.Sommeretal.(2004)reportedthatGHGemissionsfromcompoststockpilesmeasuredusingstaticchamberswereonly12to22percentofvaluesmeasuredusingtheintegratedhorizontalfluxmethod.

Becauseofthesefactors,fluxchambersshouldbeusedtoexaminerelativedifferences,ratherthanemissionfactorsofNH3,CH4,andN2Oemissionsfrompensurfaces,lagoons,retentionponds,manurestockpiles,orcompostwindrows.Inaddition,thesurfaceofpasturesandfeedlotpensistemporallyandspatiallyheterogeneous,withdryareas,areaswithfreshfeces,andareaswithurineofdifferentages(Woodburyetal.,2001;Coleetal.,2009a;Coleetal.,2009b).Toadequatelyrepresentthesurface,thenumberofchambermeasurementsrequired(estimatedasthecoefficientofvariationsquared/100:Kienbusch,1986)canbeverylarge(i.e.,onechamber/quaremeter:Coleetal.,2007b).


5-35

HousingThereareawidevarietyofdairycattlehousingsystemsduetovariationsinherdsizeandregionalpractices.InthenortheasternUnitedStates,herdsizetendstobesmallerandcattlearehousedinfreestallandtie‐stallbarnsandonpasture;inthewesternpartofthecountry,herdsizestendtobelargerandanimalsarehousedinfreestallbarnsordry‐lotswithfewproducersusingpasture‐basedsystems.ThesedifferencesinhousingcanleadtodifferencesinbothGHGandNH3emissions.ExamplesofreportedemissionsfromvaryinghousingsystemsarepresentedinTable5‐5.

Table5‐5:ExamplesofReportedOn‐FarmEmissionEstimatesforCH4,N2O,andNH3fromaVarietyofDairyCattleHousingSystems

Housing CountryEmissions(gcow‐1d‐1)

ReferenceCH4 N2O NH3

Barn Germany 402 64.8 Sahaetal.(2014)Tiestallbarn Austria 170‐232a 0.14‐1.2a 4‐7.4a Amonetal.(2001)Barn Germany 256 1.8 14.4 Jungbluthetal.(2001)Dry‐lot U.S. 41‐140 Casseletal.(2005)Hardstanding UK 0.03b 0.01 11 Ellisetal.(2001)Open‐freestall U.S. 410 22 80 Leytemetal.(2013)Tiestallbarn Canada 390 Kinsmanetal.(1995)Pasture NZ 300‐427 Laubach&Kelliher(2005)Dry‐lot U.S. 490 10 130 Leytemetal.(2011)Standoffpad NZ 1.66b 0.03 Luo&Saggar(2008)Barn Denmark 256 1.2 16 Zhangetal.(Zhangetal.,2005)Dry‐lot China 397 37 Zhuetal.(Zhuetal.,2014)Barn Sweden 216‐312a 21‐27a Ngwabieetal.(2009)Barn Germany 464 45 92.4 Sameretal.(Sameretal.,2011)Pasture Uruguay 372 Dinietal.(Dinietal.,2012)

*DenotesmeasurementsingLU‐1d‐1,whereaLU(livestockunit)=500kg.†MeasurementsdonotincludeentericCH4production.

Variationsinemissionsfromhousingareduetofactorssuchastemperature,dietcomposition,waterconsumption,ventilationflowrates,typeofmanurehandlingsystems,manureremovalfrequency,feces,andurinecharacteristics(i.e.,pHandtotalammoniacalnitrogen(TAN)),andtypeofbeddingused.Althoughdifferencescanbegreatbetweenemissionrates,therearesomeemissioncharacteristicsthatareconsistentacrossmoststudies.ManystudieshavereportedstrongdieltrendsinemissionsofCH4andNH3,withemissionstendingtobelowerinthelateeveningandearlymorningandthenhigherthroughoutthedaytillearlyevening(Amonetal.,2001;Casseletal.,2005;Powelletal.,2008;Sunetal.,2008;Bjornebergetal.,2009;Fleschetal.,2009;Ngwabieetal.,2009;Aguerreetal.,2011;Leytemetal.,2011).Thisstrongdieltrendinemissionscanbeassociatedwithwindspeedandtemperature,aswindstendtobelightinthelateeveningandearlymorningandthen,inmostinstances,steadilyincreasethroughoutthedaytoreachapeakinthelateafternoon.Temperaturealsoincreasesfromearlymorningtolateafternoon,andthendecreasesagain.Additionally,cattleactivitytendstoincreasefrommorningtolateafternoonasanimalswakeandbegintoeat,drink,ruminate,defecate,andurinate.Astheseactivitiesincrease,onewouldexpectanincreaseinCH4(andNH3)emissions.Therearealsoseasonaltrendsinemissions,themostprominentbeinginNH3emissions,withthelowestratesinwintercomparedwiththeotherseasons(Amonetal.,2001;Powelletal.,2008;Bjornebergetal.,2009;Fleschetal.,2009;Aguerreetal.,2011;Leytemetal.,2011).Powelletal.(2008),Fleschetal.(2009),andAguerreetal.(2011)reportedthatbarnemissionsofNH3inWisconsinwerelowestinwinter,withwinterratesaboutone‐halftoone‐thirdlowerthanthoseinthespringandsummer,whichwas


5-36

Ammonia Emissions in Dairy Cattle Housing

Asmentionedearlier,ammoniaisnotagreenhousegas,however,ammoniaemissionsareestimatedaspartofthenitrogenbalanceapproach.EmissionsofNH3fromdairycattlehousingsystemshavebeenstronglylinkedtodietarynitrogenintake,asthisaffectstheamountofureanitrogenexcretedinurine.Ofthenitrogeninthetotalcrudeprotein(CP)typicallyconsumedbyadairycowoncommercialdairyfarms,20to35percentissecretedinmilkandtheremainingnitrogenfromCPisexcretedaboutequallyinfecesandurine.Feednitrogen(N=CP÷6.25)useefficiency(percentageoffeednitrogensecretedasmilknitrogen)andthe50:50fecalnitrogen:urinarynitrogenexcretionratiocanbeinfluencedgreatly,however,bywhatisfedtothecow.Feedingnitrogeninexcessofnutritionalrequirementshasveryfewsignificantimpactsonmilkproductionorquality;itdecreasesfeednitrogenuseefficiencyandincreasestherelativeamountofureanitrogenexcretedinurine.Theureanitrogencontainedincowurine(whichis55to80percentofthenitrogencontainedinurine,dependingonconcentrationsofCPintheration)isthemajorsourceofNH3emissionfromdairyfarms.Ureaisproducedwhennitrogen‐richproteinsand/ornon‐proteinnitrogensourcesbreakdown(mainlyinthecowrumen),formingNH3gasthatmaybeusedbyruminalmicrobestoproducemicrobialproteinsorcanbeabsorbedthroughtheruminalwalltothebloodstream.Inthekidney,bloodNH3fromthedigestivetractortissuemetabolismiseventuallyconvertedtoureabeforebeingexcretedintheurine.Ureaseenzymes,whicharepresentinfecesandsoil,rapidlyconvertexcretedureatoammonium,whichcanbehydrolyzedquicklyintoNH3gasandlosttotheatmosphere.Thus,theincreaseinureanitrogenexcretionduetoexcessiverationCPincreasesNH3emissionsduringthecollection,storage,andlandapplicationofmanure(Rotz,2004;Misselbrooketal.,2005;Powelletal.,2008;Arriagaetal.,2010).

Pauletal.(1998)examinedtheeffectsofalteringdietaryCPonNH3lossesfromdairycows.TheyreportedthatNH3emissionsduringthefirst24hoursfollowingmanureexcretionwere38and23percentofthetotalmanurenitrogenfromdietswith16.4and12.3percentCPconcentrations,respectively,and22and15percentoftotalmanurenitrogenfromdietscontaining18.3and15.3percentdietaryCP,respectively.Misselbrooketal.(Misselbrooketal.,2005)reportedthatreducingdietaryCPcontentresultedinlesstotalnitrogenexcretionandasmallerproportionoftheexcretednitrogenbeingpresentinurine;urinenitrogenconcentrationwas90percentgreaterforthehigh‐CPthanthelow‐CPdiet.

However,Lietal.(2009)foundnoeffectofloweringdietaryCPinlactatingdairycattleonNH3emissionsfromthefloorofanaturallyventilatedfreestalldairybarnatlowandmoderatetemperatures(0to20°C).ThislackofresponsetoCPislikelyduetothefactthatureaseactivityisnegligibleattemperaturesbelow10°C(Bluteauetal.,2009).FactorsthatareessentialindeterminingNH3emissionsaremanureorurinepHandthetotalammoniacalnitrogencontent,bothofwhicharerelatedtothedietaryCPlevel.

ThemajorityofNH3emissionsfromhousingsystemsareduetothevolatilizationofNH3fromurinedeposition.Asdiscussedabove,nitrogenintakedrivestheamountofureathatisexcretedintheurine.Asthisurineisdepositedonbarnfloors,pastures,ordry‐lots,itmixeswithureasefromeitherfecesorsoilandisthenhydrolyzedtoammoniumand,viaeffectsofpH,convertedtoNH3andlosttotheatmosphere.ThelossofNH3happensrapidly,withmostNH3lossesoccurringwithin24hoursfollowingdeposition.Therefore,estimationofNH3emissionsneedstotakeintoaccounttheamountofureageneratedbythecow,pH(urine,manure,orsoil),temperature,andairflowoverthesource.StrategiesthatreducenitrogenexcretionwillbeverybeneficialinreducingNH3emissionsfromhousing/pasturesystems.


5-37

attributedtocoldwintertemperatures.Ingeneral,N2Oemissionsfromhousingwerefoundtobelowandshowednodiscernibledielorseasonaltrends(Bjornebergetal.,2009;Ngwabieetal.,2009;Adviento‐Borbeetal.,2010;Leytemetal.,2011),suggestingthattheseemissionsfromthissectoroftheproductionsystemareofrelativelylittleconcern.ThereareconsistentreportsofbothdielandseasonalvariationsinbothCH4andNH3emissions,soitisimperativethatthesefactorsbecapturedinanyestimationofemissionsforagivenproductionsystem.

EmissionsofCH4aredominatedbyentericfermentationinhousing/pasturesystems.Amonetal.(2001)examinedCH4emissionsfromatie‐stalldairybarninAustriausingeitheraslurry‐basedsystemorstraw‐basedsystem.Inbothsystems,about80percentofthenetCH4emissionswereduetoentericfermentation,withtheremainingamountcomingfromthemanure.Sunetal.(2008)measuredCH4emissionfromdairycowsandfreshmanureinchambers,andreportedthatfreshmanurealonedidnotproducenoticeableCH4fluxes.Insomedairyproductionsystems,manureisremovedfromtheanimalhousingareafrequently;therefore,CH4emissionsfromanimalhousingareasofadairycanbelargelyattributedtoentericemissions.

N2Oemissionstendtobenegligiblefrombothanimalsandfreshmanure.ThemajorityofN2Oemissionsresultfrommanurestorage,pasture,andlandapplicationofmanures.Therefore,themainsourcesofN2Oemissionsfromanimalhousingwouldbefromdry‐lotdairiesandstand‐offpads,becausethereispotentialfordepositednitrogentobenitrifiedanddenitrifiedunderwetconditionsandlostasN2O.LuoandSaggar(2008)measuredN2OandCH4emissionsfromadairyfarmstand‐offpadinNewZealandandreportedN2Ofluxesfrom0to3gN2O‐Nday‐1,whichtheyattributedtotheconcentrationsofwaterandnitrateinthepadmaterials.Overall,only54gofN2O‐Nwasemittedfromthepadoverthetimeofuse,representing~0.01percentoftheexcretanitrogendepositedonthepad.

Whiletherehavebeenoverallimprovementsinmilkproductionwithbreedingprograms,thereisnoevidencethatanybreedofdairycowproduceslessentericCH4.MüngerandKreuzer(MüngerandKreuzer,2008)measuredentericCH4productionfromHolstein,Simmental,andJerseycowsandfoundnopersistentdifferencesinCH4yields,withaverageentericCH4beingapproximately25gCH4kgDMI‐1.

5.3.1.1 MethodforEstimatingEmissionsfromDairyProductionSystems

Methodfor Estimating CH4 Emissions from Enteric Fermentation in Dairy Cows

Millsetal.(2003)developedaseriesofsubmodelstoestimateentericCH4emissionsfromdairyandbeefcattle.TheoptimalmodelappearedtobeanonlinearMits3equation,whichisutilizedbytheDairyGEMModel(asubsetofIFSM)(Rotzetal.,2011b)andisshowninEquation5‐1(Mits3equation)isbasedprimarilyonmetabolizableenergyintake,aciddetergentfiber(ADF),andstarchcontentofdiet.

Datasourcesareuserinputondietaryintake,aswellasdietarydatafromtheFeedstuffsCompositionTable(Ewan,1989;Preston,2013).

UseoftheDairyGEM/Mits3equationisrecommendedovertheIPCCTier2equation(IPCC,2006)becauseithasproventobemoreaccurate,ingeneral,fordairycows.


5-38

TheEmaxisconstantforallanimalsat45.98MJ/head/day.Theshapeparameter“c”iscalculatedfromthedietarynon‐fibercarbohydrate(NFC)toaciddetergentfiber(ADF)ratioinEquation5‐2.

Millsetal.(2003)notedthatnonlinearmodelshavetwoadvantagesoverlinearmodels:1)amaximumemissionisset;and2)itisexplainablefromabiologicalsense.Thefeedstuffcharacteristicsneededtocalculateemissionsfromdairycattleareincludedintheexamplebelow(Ewan,1989;Preston,2013).ThefulltablecanbefoundinAppendix5‐B.

Table5‐6:ExampleFeedstuffsTablea

FeedstuffDM%

Energy Protein FiberEE%

ASH%

Ca%

P%

K%

Cl%

S%

ZnppmTDN

%NEm NEg NEl

(Mcal/cwt.)

DE(%ofGE)*

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

AlfalfaCubes

x91 57 57 25 57 18 30 29 36 46 40 2.0 11 1.30 0.23 1.9 0.37 0.33 20

Alfalfadehydrated17%CP

92 61 62 31 61 65.16 19 60 26 34 45 6 3.0 11 1.42 0.25 2.5 0.45 0.28 21

Alfalfafresh

24 61 62 31 61 62.54 19 18 27 34 46 41 3.0 9 1.35 0.27 2.6 0.40 0.29 18

Source:Preston(2013).

Equation5‐1:Non‐LinearMits3Equation

exp .

Where:

CH4 =Entericmethaneemissionsperday(kgCH4head‐1day‐1)

Emax =MaximumpossibleCH4emissions(MJhead‐1day‐1)

c =Shapeparameterdeterminingemissionchangewithincreasingmetabolizableenergyintake(seeEquation5‐2)

x =Metabolizableenergyintake(MJhead‐1day‐1)

0.018=ConversionofMJtokgofCH4(kgCH4MJ‐1)

Equation5‐2:CalculatingShapeParameter

. .

Where:

c =Shapeparameterdeterminingemissionchangewithincreasingmetabolizableenergyintake(unitless)

NFC =[(100‐NDF+CP+EE)/100]xDMI(kghead‐1day‐1)

DMI =Drymatterintake(kgdryfeedanimal‐1day‐1)

ADF =AcidDetergentFiber(kghead‐1day‐1)

NDF =NeutralDetergentFiber(%)

CP =CrudeProtein(%)

EE =Etherextract(%)


5-39

aColumnheadings:DM =Drymatter GE = Grossenergy ASH =AshTDN =Totaldigestiblenutrients CP =Crudeprotein Ca =CalciumNEm =Netenergyformaintenance UIP = Undegradableintakeprotein P =PhosphorousNEg =Netenergyforgrowth CF = Crudefiber K =PotassiumNEl =Netenergyforlactation ADF = Aciddetergentfiber Cl =ChlorineMcal =Megacalories NDF = Neutraldetergentfiber S =Sulfurcwt =Centumweight(hundredweight) eNDF = effectiveneutraldetergentfiber Zn =ZincDE =Digestibleenergy EE = Etherextract ppm =partspermillion

MethaneEmissionsfromDairyCows’Housing

TheDairyGEMModel(Rotzetal.,2011a)calculatesCH4emissionsfrombarnfloorsusinganempiricalmodeldevelopedfromthreefreestallbarns(Chianeseetal.,2009c).

Whenmanureisallowedtoaccumulateasastockpile,onadry‐lot,orinapitbelowtheanimalconfinement,theDairyGEMmodelusestheIPCC(2006)Tier2methodtoestimateCH4emissions(Equation5‐4).Thisisthesameequationusedforestimatingemissionsfrommanurethatismanagedoutsideofhousing(seeSection5.4.1TemporaryStackandLong‐TermStockpileand5.4.2 Composting for details).

Methodfor Estimating Dairy Cows’ GHG Emissions from Housing

Methane

TheDairyGEMModel(asubsetofIFSM)(Rotzetal.,2011a)calculatesCH4emissionsfromhousingsurfaces.

DairyGEMusestheIPCC(2006)Tier2methodtoestimateCH4emissionswhenmanureisallowedtoaccumulateinthehousing.

NitrousOxide

NitrogenexcretedestimatedusingequationsprovidedinASABED384.2. IPCC(2006)Tier2approachforN2Oemissionsfrommanureinhousing.

Equation5‐3:CalculatingCH4EmissionsfromBarnFloors (Chianeseetal.,2009c)

. , .

Where:

CH4=Methaneemissionsperday(kgCH4head‐1day‐1)

T =Barntemperature(˚C)

Abarn =Areaofthebarnfloorcoveredwithmanure(m2)


5-40

ThemaximumCH4producingcapacity(B0)formanurevariesbyanimalcategoryandisprovidedinTable5‐19.TheCH4conversionfactors(MCF)formanuredepositedonadry‐lot,storedinadeeppit,orfromcattlebeddingcanbefoundinTable5‐7.TheMCFsformanurestoredasastockpileareprovidedinTable5‐20throughTable5‐22.TheMCFsformanurecompostedwithinhousingareprovidedinTable5‐24.

Table5‐7:MethaneConversionFactorsforDry‐Lots,PitStorageBelowAnimalConfinement,andCattle/SwineBedding

Temperature Dry‐Lot

PitStorageBelowAnimalConfinementand

Cattle/SwineDeepBedding

<1month >1month

Cool

≤10°C

1% 3%

17%11°C 19%12°C 20%13°C 22%14°C 25%

Tem

perate

15°C

1.5% 3%

27%16°C 29%17°C 32%18°C 35%19°C 39%20°C 42%21°C 46%22°C 50%23°C 55%24°C 60%25°C 65%

Warm 26°C

2% 30%71%

27°C 78%≥28°C 80%

Source:IPCC(2006).

Equation5‐4:IPCCTier2ApproachforEstimatingCH4 EmissionsinHousing

.

Where:

ECH4 =CH4emissionsperday(kgCH4day‐1)

m =Totaldrymanureperdaya(kgdrymanureday‐1)

VS =Volatilesolids(kgVS(kgdrymanure)‐1)

B0 =MaximumCH4producingcapacityformanure(m3CH4(kgVS)‐1)

MCF =CH4conversionfactorforthemanuremanagementsystem(%)

0.67 =Conversionfactorofm3CH4tokgCH4


5-41

TheSommermodelisusedtoestimateemissionsfromanyliquidmanure(lessthan10percentdrymatter)storedinhousing.TheestimationmethodforliquidmanurecanbefoundinSection5.4.4AnaerobicLagoon,RunoffHoldingPond,StorageTanks.

NitrousOxideEmissionsfromDairyCows’Housing

Toestimatenitrogenlossesfromhousing,theamountofnitrogenexcreted(Nex)byeachanimalcategoryisfirstestimated.Equation5‐5,Equation5‐6,andEquation5‐7aretheequationsrecommendedbytheAmericanSocietyofAgriculturalandBiologicalEngineers(ASABE)forestimatingNex.

SomeofthenitrogenexcretedisvolatilizedasNH3,hence,theestimationofNH3lossesisnecessarytoestimateN2Oemissionsusinganitrogenbalanceapproach.TheNH3lostfrommanureinhousingisestimatedasafractionofNex,KoelschandStowell(2005)provideestimatesonthetypicalNH3lossfromdifferenthousingfacilitiesandanimalspeciesasafractionofNex(seeTable5‐8).Arange

Equation5‐5:ASABEApproachforEstimatingNitrogenExcretionfromLactatingCows

. . . ..

Where:

Nex =Totalnitrogenexcretionperanimalperday(gNanimal‐1day‐1)

Milk=Milkproductionperanimalperday(kgmilkanimal‐1day‐1)

DIM =Daysinmilk(days)

DMI =Drymatterintake(kganimal‐1day‐1)

CCP =Concentrationofcrudeproteinoftotalration(gcrudeprotein(gdryfeed)‐1)

BW =Averagelivebodyweight(kg)

Equation5‐6:ASABEApproachforEstimatingNitrogenExcretionfromDryCows

. . .

Where:




Equation5‐7:ASABEApproachforEstimatingNitrogenExcretionfromHeifers

. .

Where:





5-42

ofvalueshasbeenprovidedforeachfacilitytype;thelowervaluesshouldbeusedduringthewinter,thehighervaluesshouldbeusedduringthesummer,andintermediatevaluesshouldbeusedforthespringandautumn.

Table5‐8:TypicalAmmoniaLossesfromDairyHousingFacilities(PercentofNex)

FacilityDescription %Loss FacilityDescription %Loss

Opendirtlots(cool,humidregion) 15‐ 30 Roofedfacility(shallowpitunderfloor) 10‐ 20Opendirtlots(hot,aridregion) 30‐ 45 Roofedfacility(beddedpack) 20‐ 40Roofedfacility(flushedorscraped)Roofedfacility(dailyscrapeandhaul)

5‐15Roofedfacility(deeppitunderfloor‐includesstorageloss)

30‐40

Source:KoelshandStowell(2005).

N2Oislostfromtheexcretednitrogen.AquantitativemethodforestimatingN2OemissionsfromsolidmanureistheIPCCTier2approach,whichisalsousedfortheU.S.GreenhouseGasInventory(Equation5‐8).ThisestimationmethodisthesameasthemethodpresentintheTemporaryStackandLong‐TermStockpileandthe

Compostingsections(SeeSections5.4.1and0).Thisequationwillover‐estimatetheemissionsfromanimalhousingifsomeofthenitrogenexcretedismanagedoutsideofhousing(i.e.,theequationaccountsfornitrogenlossduetoNH3emissionsbutdoesnotaccountforthequantityofnitrogenthatismanagedinmanuremanagementsystems).

Formanureindeeppits,dry‐lots,ormixedwithbedding,theemissionfactorsareprovidedinTable5‐9.TheN2OemissionfactorsformanureinhousingthatisstoredinastockpileareprovidedinTable5‐23.TheemissionfactorsformanurethatiscompostedwithinahousingareaareprovidedinTable5‐25.

Table5‐9:N2OEmissionFactorsforManureStoredinHousing

Category N2OEmissionFactor(kgN2O‐N/kgN)CattleandSwineDeepBedding(ActiveMix) 0.07CattleandSwineDeepBedding(NoMix) 0.01PitStorageBelowAnimalConfinements 0.002Dry‐Lot 0.02

Source:IPCC(2006).

Equation5‐8:IPCCTier2ApproachforEstimatingN2OEmissionsfromHousing

, % /

Where:

EN2O,housing =Nitrousoxideemissionsfromhousingperday(kgN2Oday‐1)

N =Numberofheadoflivestockspecies(animal)


%NH3loss =PercentofNexlostasNH3inanimalhousing‐seeTable5‐8

EFN2O =N2Oemissionfactorformanureinhousing(kgN2O‐NkgN‐1)

=ConversionofN2O‐NemissionstoN2Oemissions

=Conversionofgramstokilograms


5-43

TheremainingnitrogenexcretedthatisnotlostasN2OorvolatilizedasNH3inhousingthenentersmanurestorageandtreatment.Ifdataarenotavailabletotrackthenitrogenthatistransferredalongwiththemanure‐to‐manurestorageandtreatment,thenitrogencanbeestimatedasdescribedinEquation5‐9.However,thisequationisoverestimatingthenitrogentransferringtomanurestorageandtreatmentassomenitrogenwillbelostinhousing.ThisremainingtotalnitrogenvalueisaninputintotheN2Oequationsformanurestoredortreated.

TheDairyGEMModelprovidesdailyestimates;userscanrefertothatmodelforamorein‐depthanalysisoftheiremissions.

5.3.1.2 RationaleforSelectedMethodforEstimatingEmissionsfromDairyProductionSystems

Thereareavarietyofmethodsandmodelsavailabletoestimateemissionsfromdairyproductionsystems,rangingfromsimplecarbonfootprintmodelstohighlycomplexprocess‐basedmodelsforthedeterminationofNH3andGHGemissions.TheIPCCTier1methodologyprovidesasimplisticmethodusedforcountryinventorypurposes.Whenadditionaldataareavailable,thereareaseriesofequationsthatcanbeusedtodevelopIPCCTier2estimates.Thedatausedfortheseestimatesaretypicallyeasilyobtainablefromtheproductionfacilityoravailableinalookuptable.Whilethesemethodsprovideestimatesforemissionsthatmaybesuitableforaroughdeterminationofemissionsinventories,theyareinsomecasesbasedonverylimiteddataandmaynotbeveryrepresentativeofemissionsatthefarmlevel.Thedevelopmentofprocess‐basedmodelshasprovidedawaytoobtainamoredetailedanalysisofemissionsatthefarmscale.

Awidevarietyofmodelsapplicabletodairyproductionfacilitieswereidentifiedandevaluated,including:CarbonAccountingforLandManagers;ClimateFriendlyFoodCarbonCalculator;CoolFarmTool;CPLAN;DairyGEM;DairyWise;FarmingEnterpriseGHGCalculator;FarmGHG;Holos;IntegratedFarmSystemModel(IFSM);ManureAndNutrientReductionEstimator(MANURE);ManureDeNitrification‐DeComposition(ManureDNDC);OVERSEER;andSIMSDairy.

ThesemodelswereevaluatedtodeterminetheirsuitabilityforusetodetermineemissionsestimatesfordairyproductionfacilitiesintheUnitedStates.ElevencriteriawereusedtoidentifymodelsthatcouldbeusedtoestimateCH4fromentericCH4productionandCH4,N2O,andNH3fromanimalhousingsystems.Twoofthecriteriawereconsideredcritical:themodelhadtoberelevanttoU.S.climateanddairyproductionsystemsandithadtobepublicallyavailable.Ifthemodelsmetthesetwocriteriatheywerefurtherrankedbasedontheremainingninecriteria.Fourofthemodelsconsideredmetthecriticalcriteria:DairyGEM,IFSM,CoolFarmTool,andMANURE.AlthoughDairyGEMisasubsetofIFSM,itwasincludedseparatelybecauseDairyGEMonly

Equation5‐9:TotalNitrogenEnteringManureStorageandTreatment

% /

Where:

TNstorage =Totalnitrogenenteringmanurestorage(kgNday‐1)

N =Numberofheadoflivestockspecies(animal)


%NH3loss =PercentofNexlostasNH3inanimalhousing‐seeTable5‐8

=Conversionofgramstokilograms


5-44

estimatesemissionsfromtheanimalhousingandmanurestoragearea.Therefore,itislesscumbersometouseandrequiresfewerinputs.

Outofthesefourmodels,DairyGEMhadthemostflexibilityfordescribingtheproductionsystemandmetallofthespecifiedcriteria.Inaddition,thismodelimplementsemissionestimatemethodologiesthatareadvancedbeyondtheIPCCTier2determinations.ItmodelsCH4emissionsfromentericfermentationandmanuremanagementandthenitrogenbalanceassociatedwithnitrogenexcretedinmanure.TheunderlyingmethodsintheDairyGEMmodelarerecommendedfordeterminingCH4emissionsfromentericfermentationandhousingsystemsfordairycattle(seefurtherdiscussioninAppendix5‐E,Table5‐E‐1,andsubsequentrelevanttext).Theestimatesgeneratedfromthismodelcouldthenbemodifiedtoaccountformitigationstrategiesthatcouldaltertheemissionscurrentlybeinggeneratedon‐farm.Somemitigationstrategiesarealreadyembeddedinthemodel,suchasalternativefeeding,manurehandling/storage,andtheuseofbovinesomatotropin,whileotherscouldbeusedbydevelopingatablewithmodifiersbasedonliteraturevaluestodeterminehowon‐farmemissionscouldchangewiththeimplementationofthesestrategies.ForN2Oemissions,anitrogenbalanceapproach(basedontheconceptsinDairyGEM)usingnitrogenexcretionequationsfromASABEStandardD384.2isrecommended.TheuseoftheASABEequationstakesintoaccounttheimpactofdietarychangesonnitrogenexcretion.

5.3.2 EntericFermentationandHousingEmissionsfromBeefProductionSystems

Becauseofdifferencesinthediets,animalphysiologicalstateandage,andmanurehandling,theproportionsandsourcesofGHGsdifferamongthecow‐calf,stocker,andfinishingsegmentsofthebeefcattleindustry.AprimarysourceofGHGsfromthebeefcattleindustryisentericCH4,producedprimarilyintherumen,althoughsomeCH4isalsoproducedinthelowergut.Inaddition,CH4andN2Omaybeproducedfromfecesandurineonpasturesandfeedlotpensurfaces.Emissions

Model Evaluation Criteria for Dairy Production Systems

1. Themodelisbasedonwell‐established,scientificallysoundrelationshipsamongfarmmanagementinputs,emissionsoutputs(process‐based/mass‐balancemodelpreferable).

2. ThemodelisrelevanttoU.S.climateanddairyproductionsystems.3. ThemodelcanestimateCH4,andN2O,andNH3emissionsfromdairyhousingsystems

(includingentericCH4production).4. Thereisflexibilityinthemodeltodescribetheproductionsystem(animals,feed,

housing,andin‐housemanuremanagement).5. Themodeliseasytouseandisdesignedtouseeasilyobtainablefarminformationto

determineemissionsestimates.6. ModelemissionestimatesforbothentericCH4productionandemissionsassociated

withcattlehousingareeasilycaptured.7. Themodelincludessomemitigationstrategiesforreducingemissionsandproduces

realisticchangesinemissionsvalueswhenthesechangesaremadewithintheproductionsystem.

8. Thereistransparencyinthemodelcalculations,andtechnicalguidelinesareavailabletoelaboratethemethodologiesusedtoobtaintheemissionsestimates.

9. Themodelhasbeentested/validatedwithon‐farmdata.10. Themodelworksreliably(littletonoerrorsorprogramcrashes).11. Themodelispubliclyavailableandaccessible.


5-45

fromhousingandmanurehandling(priortoenteringamanagementsystem)arediscussed,andequationsforstockpiledmanure(Section5.4)canbeappliedforemissionestimation.

Phetteplaceetal.(2001)estimatedGHGemissionsfromsimulatedbeefanddairy4systemsintheUnitedStatesusingmodificationsoftheIPCC(1997)methodology.Thesystemswerecomprisedofabaseherdofmaturecowspluscalvesandreplacements,stockercalves,afeedlot,andadairywith100lactatingcows.Theyalsoevaluatedemissionsfromcalvesthatwentthroughtheentirecow‐calf,stockerandfeedlotsystem(cow‐calftofeedlot).Greenhousegasemissionshead‐1(CO2‐eq)fromPhetteplaceetal.(2001)arepresentedinTable5‐10(withtheexceptionofthedairyherd).

Table5‐10:SimulatedGHGEmissionsforRuminantSystems(kgCO2‐eq/head/year)

Item Cow‐calf Stocker Feedlot Cow‐calfThroughFeedlot

DietaryTDN,% 62 57 88 62GHG(kgCO2‐eq/head/year)

EntericCH4 1,140 1,725 743 1,167ManureCH4 34 48 12 34TotalCH4 1,175 1,773 755 1,201N2O 1,487 1,721 1,294 1,490CO2 127 380 1,245 252

TotalCO2‐eq 2,788 3,874 3,294 2,944Source:Phetteplaceetal.(2001).

Elsewhere,Beaucheminetal.(2010)usedtheHolosmodel(Littleetal.,2008)toconductalife‐cycleassessmentofbeefproductioninwesternCanada.OftotalCO2‐eq,63percentwasfromentericCH4.5TheseareverysimilartovaluesreportedbytheU.S.DepartmentofAgriculture(2004b).Sixty‐onepercentofCO2‐eqemissionswerefromthecow‐calfherd,19percentwerefromreplacementheifers,eightpercentwerefrombackgroundingoperations,and12percentwerefromfeedlots.SeventyninepercentofentericCH4losseswerefromthecowherd,threepercentfrombulls,twopercentfromcalves,sevenpercentfrombackgrounders,andninepercentfromfeedlots.N2Ocontributions(CO2‐eq)asapercentoftotalGHGemissionswereasfollows:feedlotmanure–twopercent,feedlotsoil–twopercent,cow‐calfherdsoil–twopercent,andcow‐calfherdmanure–20percent.

Cow‐CalfandBullsThereisnoevidencethatanybreedofbeefcowproduceslessentericCH4thananother.Thereareafewreportssuggestingthatefficientcattle(thoseselectedforfeedefficiencyorresidualfeedintake(RFI))mayproducelessentericCH4(Nkrumahetal.,2006;Hegartyetal.,2007).However,FreetlyandBrown‐Brandl(2013)reportedthatcattlewithgreaterfeedefficiencyactuallyproducedmoreCH4;thusraisingsomequestionsaboutthegeneticfactorsassociatedwithfeedefficiencyandCH4emissions.Itisunclearwhetherthechangesobservedarearesultofalteredfeedintakeorareassociatedwithachangeinalteredruminalmicrobialpopulation.Additionally,recentinformationindicatesthatthereisaninteractionbetweendietqualityandfeedefficiencyonentericCH4emissions,whereefficientcowsproducelessCH4whengrazinghigh‐qualitypasturebutnotwhengrazingpoor‐qualityforage(Jonesetal.,2011).Residualfeedintakeismoderatelyheritable—(0.28to0.58;Mooreetal.,2009),thusitmightbepossibletogeneticallyselectforanimalswithlowerentericCH4production.AnexaminationofthevalueforselectionforlowentericCH4productionhasbeenconductedwithsheepinNewZealandandAustralia.Simulationsusingpublisheddata

4DiscussionofemissionsfromdairyproductionsystemscanbefoundinSection5.3.1.55%ofemissionswerefrommanureCH4,23%frommanureN2O,4%fromsoilN2O,and5%fromenergyCO2.


5-46

indicatethatwithoutaccuratefeedintakeinformationandamethodbywhichmanyanimalscanbescreenedforCH4emissions,selectionforlowerentericCH4productionisnotlikelytobeeconomicallyviable(Cottleetal.,2011).

MeasurementofentericCH4fromgrazingcattlehasbeenconductedprimarilyfromanimalsgrazingimprovedpasturesusingmicrometeorologicalmethodsandtracertechniques.Lassey(2007)summarizedmuchoftheCH4emissionsdatathathadbeencollectedusingtheSF6tracertechnique.Intakewaseithercalculatedfromarequirementsmodelorfromuseofmarkers(Cr2O3orYb2O3).Estimatedforagedigestibility(invitro)rangedfrom48.7to83percent,whichresultedinestimatedCH4conversionfactors[i.e.,entericCH4asapercentageofgrossenergyintake(GEI)]rangingfrom3.7to9.5percent.ThemeanYmfromallofthestudieswas6.25andagreesreasonablywellwiththatusedbyIPCC(2006)forcattleonpasture.Methaneemissionsfromcowsgrazingimprovedpasture,Kentuckyfescue,andBermudagrassinthesouthernUnitedStateswerereportedbyPavao‐Zuckermanetal.(1999)andDeRamusetal.(2003).InbothofthesestudiessignificantreductionsinentericCH4unit‐1ofanimalweightgainresultedfromtheimplementationofbestmanagementpracticesdesignedtoimprovepasturequality.

Entericemissionsestimatescanbemadeusingmicrometeorologicalmethodsandtracertechniques.OnereportinwhichCH4emissionsweremeasuredfrombeefcowsgrazingnativerangeinOctoberandMayillustratedalargevariationinentericemissions.InOctober,whencowswerelosingBW,theyproduced87gCH4headdaily‐1,andonthesamepastureinMaytheyproduced252gCH4headdaily‐1(Olsonetal.,2000).Westbergetal.(2001)measuredCH4fromcowsgrazingthesamepastureacrossseasonsandfoundsimilarresults,withhigherCH4emissionsfromcowsgrazinglushspringgrowthandthelowestemissionsfromgrazingstockpiledfallpasture.ThesedifferencesareattributabletodifferencesinbothDMIandforagequality.Ingeneral,asforagequalityincreases,DMIalsoincreases.Some"rulesofthumb"forDMIonpastureincludethefollowing:

Poorqualitypasture‐DMI=1to1.75percentofbodyweight; Mediumqualityforage‐DMI=1.75to2.25percentofbodyweight; HighqualityforageDMI=2.25to3percentofbodyweight.

StockersEntericCH4emissionsofstockerswhilegrazinghavebeenmeasuredbyLaubachetal.(2008),Tomkinsetal.(2011),McGinnetal.(2011),andBoadietal.(2002),usingavarietyoftechniquesincludingtheSF6tracer,andseveralmicrometeorologicalapproaches.ThesamefactorsthataffectCH4emissionsfromgrazingbeefcowsareimportantinstockercattle.Thosefactorsareleveloffeedintake,digestibilityofforageconsumed,supplementation,andthechemicalcompositionoftheplantsconsumed.Entericemissionsestimatescanbemadeusingmicrometeorologicalmethodsor,tracertechniquesorcanbepredictedfromIPCCTier2methods(seeentericdiscussion).Criticalvariablesincludemeasurementsorestimationsoffeedintakeandfeedquality(chemicalcomposition).Manyoftheequationscurrentlyavailablemaynotaccuratelypredictmeasuredentericemissionsfromgrazingcattle(Tomkinsetal.,2011).

FeedlotMostestimatesofentericmethaneemissionfromfinishingbeefcattlearebasedonworkusinganimalsconfinedtorespirationchambers,althoughafewstudieshaveusedmicrometeorologicalmethodsinopenfeedlots.EntericCH4lossesfromfinishingbeefcattlenormallyrangefrom50to200Lhead‐1daily(JohnsonandJohnson,1995;McGinnetal.,2004;Beaucheminetal.,2008;Lohetal.,2008;Halesetal.,2012;2013;Halesetal.,2014;Toddetal.,2014a;Toddetal.,2014b).InmoststudiesintheU.S.,dietshavebeenbasedonDRCorSFC;whereasmoststudiesinCanadathedietsarebasedonbarley.TheIPCCTier2(2006)entericCH4conversionfactor(Ym)forfeedlotcattleis


5-47

3±1percentofGEI.TherearefewstudiesthathavemeasuredemissionsofCH4andN2Ofromfeedlotpensurfacesandrunoffcontrolstructures.Theprimaryfactorsthatcontrolentericmethaneemissionsinfeedlotcattlearefeedintake,graintype,grainprocessingmethod,dietaryroughageconcentrationandcharacteristics,anddietaryfatconcentration.

5.3.2.1 MethodforEstimatingEmissionsfromBeefProductionSystems

aCalculatedusingEqn10.3inIPCC(2006)basedonbodyweight(“BW”).bCalculatedusingEqn10.4inIPCC(2006)basedonNEaandfeedingsituation.cCalculatedusingEqn10.8inIPCC(2006)basedonmilkproduction(“milk”)andmilkfat(“fat”).dCalculatedusingEqn10.11inIPCC(2006)basedoninformationondailyhoursofwork(“work”).eCalculatedusingEqn10.13inIPCC(2006)basedonNEmandpregnancystatus.fCalculatedusingEqn10.14inIPCC(2006)basedonDE.gCalculatedusingEqn10.13inIPCC(2006)basedonbodyweight,matureweight(“MW”),anddailyweightgain(“WG”).hCalculatedusingEqn10.15inIPCC(2006)basedonDE.

MethodforEstimatingCH4EmissionsfromEntericFermentationinBeefCattle

IPCCTier2approach,withsomeadjustmentfactors,basedondiet,animalweight,pregnancy/lactation,activity(IPCC,2006).

Datasourcesareuserinputsondietaryintake,lactationandpregnancyrates,animalweight,housing,andtheFeedstuffsCompositionTable(Ewan,1989;Preston,2013).

Althoughtheequationsutilizedarethesameasexistinginventorymethods,themethodtakesintoaccountalargedatabaseoffeedtypes(foundinAppendix5‐B,FeedstuffCompositionTable),aswellasreportingatthemonthly,ratherthanannual,temporalscale.

Equation5‐10:IPCCTier2EquationforCalculatingGrossEnergyRequirementsforBeefCattle

GE

NE NE NE NE NEREM

NEREG

DE%100

Where:GE =Grossenergy(MJday‐1)

NEm =Netenergyrequiredbytheanimalformaintenance(MJday‐1)a

NEa =Netenergyforanimalactivity(MJday‐1)b

NEl =Netenergyforlactation(MJday‐1)c

NEwork=Netenergyforwork(MJday‐1)d

NEp =Netenergyrequiredforpregnancy(MJday‐1)e

REM =Ratioofnetenergyavailableinadietformaintenancetodigestibleenergyconsumedf

NEg =Netenergyneededforgrowth(MJday‐1)g

REG =Ratioofnetenergyavailableforgrowthinadiettodigestibleenergyconsumedh

DE =Digestibleenergyexpressedasapercentofgrossenergy(%)


5-48

TheDEultimatelyusedintheIPCCTier2equation(inEquation5‐11)willbeweightedbasedonportionoftotalfeedintakefromaparticularfeedtype.TheDEdataforparticularfeedstuffscanbefoundinAppendix5‐B.TherecommendedYmforbeefreplacementheifers,steerstockers,heiferstockers,beefcows,andbullsis6.5percentforallregionsofthecountry.Forfeedlotcattle,theIPCC(2006)Ymof3percentisadjustedbasedondiets.AllfeedlotcattleinitiallystartwithabaselineYmofthreepercent(IPCC,2006).ThecorrectionfactorstoYmforfeedlotcattlefordifferentscenariosareprovidedbelow(seeAppendix5‐Aforadditionaldetails).TheYmusedforcalculatingemissionsforthesecattleismodifiedbasedonanimaldiets,asindicatedinTable5‐11.

Table5‐11:DeterminationofAdjustedMethaneConversionFactor(Ym)forFeedlotCattle

Variable Ym(asa%ofGEI)BaselineYm(IPCC,2006) 3%Ionophoreindiet(Tedeschietal.,2003;Guanetal.,2006): Yes Nochange

No IncreaseYmby4%(Ym=3%x1.04=3.12%ofGEI)

FatContent(ZinnandShen,1996;Beaucheminetal.,2008;Martinetal.,2010)(Foreachpercentofaddedfat(assupplementalfatorinbyproductssuchasdistillersgrainthatcontainabout10percentfat),decreasebyfourpercenttoamaximumofa16percentdecrease)

1%supplementalfatDecreaseYmby4%

(Ym=3%x0.96=2.88%)

2%supplementalfatDecreaseYmby8%

(Ym=3%x0.92=2.76%)

Fourorhigheraddedfatcontent DecreaseYmby16%(Ym=3%x0.84=2.52%)

GrainType(BeaucheminandMcGinn,2005;Archibequeetal.,2006;Halesetal.,2012): Graininanimaldietissteamflaked(SF)orhighmoisture(HM) NoChange

Graininanimaldietisunprocessed(UP)ordryrolled(DR)IncreaseYm20%

(Ym=3%x1.2=3.6%)

GrainindietisbarleyratherthancornorsorghumIncreaseYm30%

(Ym=3%x1.3=3.9)GrainConcentration(seeAppendix5‐A fordetailsandreferences): Dietcontainsmorethan60percentgrain NoChange

Dietcontains45to60percentgrain IncreaseYm10%(Ym=3%x1.1=3.3%)

Dietcontainslessthan45percentgrainIncreaseYm40%

(Ym=3%x1.40=4.2%)

Equation5‐11:IPCCTier2EquationforCalculatingEntericCH4 EmissionsfromBeefCattle

/.

Where:

DayEmit =Emissionfactor(kgCH4head‐1day‐1)

GE =Grossenergyintake(MJhead‐1day‐1)

Ym =CH4conversionfactor,whichisthefractionofGEinfeedconvertedtoCH4(%)

55.65 =Afactorfortheenergycontentofmethane(MJkgCH4‐1)


5-49

EmissionsfromFeedlotPenSurfacesTherearefew,ifany,studiesthathavemeasuredCH4orN2Oemissionsfrombeefcattlefeedlotpensurfacesandretentionponds.ThestudyofToddetal.(2014a;2014b)suggeststhereislittleCH4productionfromfeedlotpensurfaces.TheuseoftheIPCC(2006)methodologiesisrecommendedtoestimateemissionsfromfeedlotpensandretentionponds.

InordertoestimateCH4emissionsfrombeeffeedlotpensurfaces,thequantityofvolatilesolidsexcretedisfirstestimated.ThesecanbeestimatedbylabtestingsamplesfromthefacilityorusingvaluesfromtheASABEStandardD384.2(ASABE,2005).6CH4emissionsfromthepensurfacecanbeestimatedusingtheIPCC(2006)Tier2approachasoutlinedinsection5.4.1.2.Forcattlefeedlots,amaximumCH4productioncapacity(B0)of0.33m3/kgvolatilesolidsisassumed(Table5‐19)andtheCH4conversionfactorforpensurfacesrangesfrom1to2percentofB0,dependinguponenvironmentaltemperature(Table5‐20).Oncemanureisscrapedfromthepensandremoved,themethodsdescribedinsection5.4.1canbeusedtoestimateCH4emissionfrommanurethatiscompostedorstoredinstockpiles.

InordertoestimateN2Oemissionsfromthepensurfacesofbeeffeedlotsthequantityofnitrogenexcretedontothepensurfacemustbeknown.ThiscanbeestimatedusingEquation5‐12fromtheASABEStandardD384.2.Forabeeffeedlot,adefaultvalueof0.069kgofNkgdrymanure‐1canbeusedifNexisnotcalculated.

6Volatilesolidsvaluescanbeestimatedfromequations(1)or(2)insection4.3.1ofASABED384.2.DefaultvolatilesolidsvaluesarealsopresentedinTable5‐32ofthisdocument.

Methodfor Estimating Beef Cattle GHG Emissions from Housing

Methane

TheIPCC(2006)Tier2methodcanbeusedtoestimateCH4emissionswhenmanureisallowedtoaccumulateonfeedlotpensurfacesasdescribedbelow.

NitrousOxide

NitrogenexcretedestimatedusingequationsprovidedinASABED384.2. IPCC(2006)Tier2approachforN2Oemissionsfrommanureinhousing.


5-50

SomeofthenitrogenexcretedisvolatilizedasNH3,hence,theestimationofNH3lossesisnecessarytoestimateN2Oemissionsusinganitrogenbalanceapproach.TheNH3lostfrommanureinhousingisestimatedasafractionofNex.KoelschandStowell(2005)provideestimatesonthetypicalNH3lossfromdifferenthousingfacilitiesasafractionofNex(seeTable5‐12).Arangeofvalueshasbeenprovidedforeachfacilitytype;thelowervaluesshouldbeusedduringthewinter,thehighervaluesshouldbeusedduringthesummer,andintermediatevaluesshouldbeusedforthespringandautumn.

Table5‐12:TypicalAmmoniaLossesfromBeefCattleHousingFacilitiesExpressedasaPercentofNex

FacilityDescription %Loss FacilityDescription %Loss

Opendirtlots(cool,humidregion) 30–45 Roofedfacility(beddedpack) 20‐40

Opendirtlots(hot,aridregion) 40–60Roofedfacility(deeppitunderfloor,includingstorageloss)

30‐40


AnalternativeapproachistousetheequationofToddetal.(2013)whichcalculatesmonthlyfeedlotNH3emissionsasafunctionofdietarycrudeproteinandaveragemonthlytemperature(Equation5‐13).

Equation5‐12:ASABEApproachforEstimatingNitrogenExcretionfromBeefCattle

..

..

.

.

.

Where:


DMIx=DryMatterIntakeforrationx(kgdryfeedanimal‐1day‐1)

CCP‐x =Concentrationofcrudeproteinoftotalration(gcrudeproteingdryfeed‐1)

DOF =Daysonfeedforanindividualration(days)

BW =Livebodyweightatfinishoffeedingperiod(kg)

BW =Livebodyweightatthestartoffeedingperiod(kg)

DOFT=Totaldaysonfeedfromstarttofinishoffeedingperiods(days)

SRW =Standardreferenceweightforexpectedfinalbodyfat(kg)

x =Rationnumber

n =Totalnumberofrationsfed


5-51

N2OemissionsarecalculatedusingtheIPCC(2006)Tier2methodanddry‐lotemissionfactorsdescribedinEquation5‐8andTable5‐9.ThequantityofnitrogenthatleavesthefeedlotpensinmanurecanthenbecalculatedusingEquation5‐9.N2O‐NlossesfrommanurecollectedandremovedfromthepenscanbedeterminedfrommanurenitrogenusingEquation5‐27andEquation5‐29andtheemissionfactorsinTable5‐23andTable5‐25foundinSection5.4ManureManagement.NH3lossesfrommanurenitrogenremovedfromthepenscanbecalculatedasdescribedinAppendix5‐C.1and5‐C.3.

5.3.2.2 RationaleforSelectedMethodforEstimatingEmissionsfromBeefProductionSystems

Cow‐Calf,Bulls,andStockersThemostappropriatepredictionsavailableforentityscaleestimationareIPCCTier2methodsforgrazingcattle.Criticalvariablesthatareimportanttodefineinordertogeneratepredictionmethodsincludemeasurementsorestimationsoffeedintakeandfeedquality(chemicalcomposition)forpastureorrangelands.Iftheintakeisnotknown,intakepredictionequations/modelssuchasNRC(2000)canbeused.TheNRC(2000)providesanequationforthecalculationofDMIforgrazingbeefcowsandforstockercattle:NEmintake=SBW0.75*(0.04997*NEm2+0.04631)whereNEmistheestimatedMcalkg‐1ofthepasture,andSBWistheaverageshrunkbodyweightfortheperiodofgrazing(kg).TherequirementforknowledgeoftheNEmconcentrationofthepasturemaylimittheusefulnessofthepredictioninsomesituations.

Insituationsinwhichtheherdishousedinadry‐lotorbarnfacility,emissionfactorsforCH4andN2Oassociatedwithpensurfaces,manurestorage,andanimalmovement/manuredisturbancewouldbeappropriate.

FeedlotEllisetal.,(2009)reportedthatseveralequationsappearedtobegoodpredictorsofentericCH4lossesfromfeedlotcattlebasedonCanadianstudies.However,manyofthoseequationstendtogreatlyoverestimateentericlosseswhencomparedwithdatafromcattlefedatypicalsouthernplainsfinishingdiet(Halesetal.,2012;2013;Toddetal.,2014a;Toddetal.,2014b).AlthoughKebreabetal.(2008)reportedthatMOLLYandIPCCTier2(2006)gavepredictedvaluessimilartomeasuredvalueswithfeedlotcattle,therewasalargevariabilityinindividualanimalswitherrorsof75percentorgreater.Kebreabetal.(2008)notedtheaverageYm(MJentericCH4MJGEI‐1)forfeedlotcattlebasedonexperimentaldatawas3.88percentofGEI(range3.36to4.56),whichwashigherthantheIPCC(2006)valueof3.0percentandtherecentlyobtainedvalueswithtypicalfinishingdietsof2.85percent(Halesetal.,2012;2013).

Equation5‐13:MonthlyBeefFeedlotNH3 EmissionsasaFunctionofDietaryCrudeProteinandMonthlyTemperature

. .

Where:

NH3 =NH3emissionfromhousingperday(gNH3head‐1day‐1)

T =Averagemonthlytemperature(K)

CP =Dietarycrudeproteinasafractionofdrymatter(%)


5-52

Currently,IPCCTier2maybethemostusefulmethodologyforpredictionofentericemissionsfromfeedlotbeefcattle.Unfortunately,theTier2methoddoesnotallowforestimatingchangesinentericemissionsrelatedtochangesindietormanagement.

Therefore,amodifiedIPCC(2006)methodisrecommendedtoestimateentericCH4emissionsfrombeefcattlefedhighconcentratefinishingdiets.TheCH4conversionfactor(Ym)willbeadjustedbyfactorsintheanimals’dietsasdescribedinSection5.3.2.1.AbaselinescenariobasedontypicalU.S.beefcattlefeedingconditionsisestablished,andtheYmvaluesareadjustedbasedonpublishedresearch.Emissionvaluesaremodifiedusingcorrectionfactorsthatarebasedonchangesinanimalmanagementandfeedingconditionsfromthebaselinescenario.

5.3.3 EntericFermentationandHousingEmissionsfromSheep

GHGemissionsassociatedwithsheepproductionincludeentericCH4emissions,manureandbeddingemissions,andemissionsassociatedwithgrazingandmanureapplicationtoland.

TheNewZealandMinistryfortheEnvironment(2010)estimatedthatsheepyoungerthanayearofageemit5.1percentofGEIasentericCH4,andadultsheepemit6.3percentoftheirGEIasCH4.Theseemissionfactors,whencombinedwithpopulationestimates,resultinbaselineentericemissionsof11.60kgCH4head‐1year‐1.Sheeparealsoestimatedtodeposit15.9kgNhead‐1year‐1.

Lassey(2007)summarizedtheentericemissionsmeasurementsfromgrazingsheeptrialsfromNewZealandandAustraliainwhichtheSF6tracertechniquewasused.Foragecharacteristicsrangedfromlush(invitrodigestibilityestimateof82percent)topoorquality(called“dead,”withaninvitrodigestibilityof54percent).Intakewasmeasuredusingcompletefecalcollectionoramarker(n‐alkane).EntericCH4emissionsrangedfrom11.7gday‐1forsheepfedforageofhigherquality(6.9percentofGEI)to35.2gday‐1forsheepfedforageoflowerquality(6.3percentofGEI).Theaverageentericemissionswere5.39percentofGEI,or23.5gday‐1.Ingeneral,lowerforagequalityresultedinagreateramountofCH4emittedasaproportionoftheenergyintakethandidhigherforagequality.

NewZealandpasturesgrazedbysheephadelevatedN2Oemissions(7.4gN2O‐Nha‐1day‐1vs.3.4gN2O‐Nha‐1day‐1)comparedwithcontrol,butsignificantlylessthanthatobservedwhencattlegrazed(32.0gN2O‐Nha‐1day‐1)(Saggaretal.,2007).ThedatawereusedtoevaluatetheNZ‐DNDCmodel,aprocess‐basedNewZealandwholefarmmodel.ToourknowledgetherearenopublishedestimatesofGHGemissionfromsheepmanuresystems.

5.3.3.1 MethodforEstimatingEmissionsfromSheep

MethodforEstimatingEntericFermentationCH4 EmissionsfromSheep

Howdenequation(Howdenetal.,1994),basedondietaryDMI. TheequationfromHowdenetal.(1994)estimatesemissionsbasedsolelyonDMI;hence,

emissionfactorsnotutilized.


5-53

ThedrymatterdataforparticularfeedstuffscanbeobtainedfromAppendix5‐B.

Noemissionsestimationmethodshavebeenprovidedforhousingasmostsheeparekeptonpastureandminimalemissionsareexpected.

5.3.3.2 RationaleforSelectingMethodforEstimatingEmissionsfromSheep

Howdenetal.(1994)generatedanequationfromwhichtopredictCH4emissionsfromsheep.Equation5‐7resultedfromalinearextrapolationofDMItoemissions.IthassincebeenevaluatedandfoundtoberobustenoughtobetheequationusedintheAustralianNationalGreenhouseGasInventory.KleinandWright(2006)measuredCH4fromsheepinrespirationchambersandcomparedtheirresultstotheHowdenetal.(1994)equation.ActualCH4averaged1.1ghead‐1(SE±0.05)andpredictedCH4was1.1ghead‐1(SE±0.02).ApotentialconcernregardingtheHowdenequationisthatmuchofthedataincludedintheanalysiswasbasedontropicalforages.Nonetheless,whenintakedataareavailable,theHowdenequationpresentsthebestmethodbywhichtoestimatesheepentericemissions.Whenintakeisnotavailable,theIPCCTier2methodofestimationshouldbeused.EmissionsfromfeedlotsheepshouldusetheYmvaluesfromBlaxterandClapperton’soriginalpaper(1965)inwhichtheymeasuredCH4emissionsfromsheepwithrespirationcalorimetrychambers.Sheepfedhighlydigestibledietsatthreetimesmaintenanceproduced35percentlessCH4(kcal100Kkcaloffeedenergy‐1)thanthosefedsimilardietsatmaintenance;thus,areducedYmvalueiswarranted.TheequationisCH4=1.3+[0.112×(%digestibility/100)]+[MEintake/maintenanceMErequirement]×[2.37‐0.050×(%digestibility/100)].

5.3.4 EntericFermentationandHousingEmissionsfromSwineProductionSystems

SourcesofGHGemissionsincludeentericfermentation;manurestoredwithintheanimalhousing,whetheritisstoredasaliquidormixedwithbedding;emissionsthatoccurduringthetransportofmanuretoanexternalmanurestoragestructure;theoutsidemanurestoragestructure;emissionsthatoccurduringtransportofmanuretothefield;andemissionsfollowinglandapplicationofmanure.BecauseGHGmitigationhasnotbeenafocusofU.S.researchfortheswineindustrynorahighpriorityforswineproducers,dataarenotreadilyavailabletoidentifythemagnitudeofeachoftheabovepointsofemissionwithinafarm.However,emissionsofCH4areexpectedtooccurprimarilyduringmanurestorage,andemissionsofN2Oareexpectedtopredominatefollowinglandapplicationofmanure.7Oftenmanureisstoredunderneaththepighousinginadeeppit.Forthisreason,emissionsdiscussioninthissectionincludesin‐housemanurestorageandcomparisonofin‐housemanurestoragesystemswithsystemsthatstoremanureexternally.Becauseswinefeedsaredry,emissionsofGHGfromfeedstorageareasarebelievedtobenegligible.

7GreenhousegasemissionsresultingfollowinglandapplicationareaddressedseparatelyinthesectionsonChapter3:CroplandsandGrazingLands.

Equation5‐14:EquationforEntericFermentationEmissionsfromSheep(Howdenetal.,1994)

. .

Where:

CH4 =Methaneemissions(kgCH4head‐1day‐1)

Intake =DryMatterIntake(kghead‐1day‐1)


5-54

Greenhousegasemissiondatafromswinefacilitiesissomewhatlimited.Liuetal.(2011a)reportedthatgrow/finishpigsemitted42to79mgCH4kgBW‐1dailyfromchamberswherepigswerehousedwithmanure.DailyemissionsofN2Orangedfrom11.4to12.4mgN2OkgBW‐1(Lietal.,2011).ThesevaluesaresomewhathigherthandatausedbyVergeetal.(2009)incalculatingGHGemissionsfromCanadianporkproduction(43mgCH4kgBW‐1and4mgN2OkgBW‐1).Philippeetal.(2007)observedGHGemissionsintherangereportedbyLietal.(2011)thoughtheirobservationswereinEuropeandeeplitterandslattedfloorsystems.Thereportedgaseousemissionsfrompigsraisedontheslattedfloorandonthedeeplitterwere,respectively,0.54and1.11gpig‐1day‐1forN2O,and16.3and16.0gpig‐1day‐1forCH4.

Liuetal.(2011a)conductedameta‐analysistoidentifyfactorsthatcontributetoGHGemissionsfromswineproduction.Findings,showninTable5‐13,illustratethattypeofemissionsource(swinebuildingsormanurestoragefacilities)wasnotsignificantforCH4andN2Oemissions.Swinecategory(stageofproduction)andgeographiclocationwassignificantforbothoftheGHGgases.Neithertemperaturenorsizeofoperationwassignificantintheoverallanalysis.

Withinthemeta‐analysis,Liuetal.(2011a)foundthatswinebuildingswithstraw‐flowsystemsgeneratedthelowestCH4andN2Oemissionsofsystemscompared,whilepitsystemsgeneratedthehighestCH4emissions,andbeddingsystemsgeneratedthehighestN2Oemissions.Emissionsfromlagoonsandslurrystoragebasin/tankswerecompared;lagoonsgeneratedsignificantlyhigherN2Oemissionsthanslurrystoragebasin/tanks,whileCH4emissionswerenotdifferent.Straw‐basedbeddingresultedinnumericallyhigherCH4butlowerN2Oemissionswhencomparedwithsawdustorcornstalkbeddingsystems.Liuetal.(2011a)observedanincreasingtrendforCH4emissionsasmanureremovalfrequencydecreased(P=0.13).DeeppitsandpitsflushedusinglagooneffluentalsogeneratedrelativelyhighCH4emissions.ResultsforN2Oemissionsshowedveryhighuncertainties(P=0.49).DeeppitsandpitswithmanureremovedeverythreeorfourmonthshadrelativelyhigherN2Oemissions.Asummaryofotherfindingsfromthemeta‐analysisconductedbyLiuetal.(2011a)showedthatCH4emissionsfromslurrystoragefacilitieswithoutcoversweresignificantlyhigherthanfromthosewithcovers.

ThehighestCH4emissionswerefromfarrowingswine,andweresignificantlyhigherthanthosefromfinishingandnurseryswine.Comparedwithfarrowingswine,thegestatingswinehadsignificantlylowerCH4emissions.ThehighestN2Oemissionswerefromgestatingswineandweresignificantlyhigherthanthosefromfinishingswine.

NorthAmericanstudiesreportedsignificantlyhigherCH4emissionsfromswineoperationsthanEuropeanandAsianstudies(Liuetal.,2011a).Thisisprobablyduetothedifferentprevailingmanurehandlingsystemsanddifferentmanurehandlingpracticesindifferentregions.EmissionsofCH4fromlagoonsandmanurestoragefacilitiesincreasedwithincreasingtemperature.Forswinebuildings,temperaturewasnotasignificantfactor.

Table5‐13:PValuesofMainEffectsonGHGEmissionsfromSwineOperations

CauseofVariation CH4(n=76)N2O

(n=53)Emissionsource 0.94 0.93Swinecategory 0.05 <0.01Geographicregion 0.04 0.02Temperature 0.20 0.95Sizeofoperation 0.89 0.24Source:Liuetal.(2011a).


5-55

5.3.4.1 MethodforEstimatingEmissionsfromSwineProductionSystems

MethaneEmissionsfromSwineHousingTheIPCC(2006)Tier2equationisusedtoestimateCH4emissionswhenmanureisallowedtoaccumulateinapitbelowtheanimalconfinement.TheestimationmethodisprovidedinEquation5‐4.ThemaximumCH4producingcapacityforswineisprovidedinTable5‐19.TheMCFsformanurestoredinadeeppitorfromswinebeddingisprovidedinTable5‐7.

NitrousOxideEmissionsfromSwineHousingToestimatenitrogenlossesfromswinehousing,theamountofnitrogenexcreted(Nex)foreachanimalclassesarefirstestimated.Equation5‐16describestherelationshipbetweennitrogenintake,retention,andexcretionforswine.Equation5‐17,Equation5‐18,Equation5‐19,andEquation5‐20providethemethodsforestimatingthenitrogenintakeandretentionforthedifferentswineclassesasrecommendedbytheASABE.

MethodforEstimatingEntericFermentationCH4 EmissionsfromSwine

IPCCTier1approach,usingU.S.emissionfactorof1.5kgCH4/head/year.(IPCC,2006). SoledatasourceistheIPCCTierIemissionfactorforswine.Userinputistotalnumber

ofhead,regardlessofclassorweight.

Equation5‐15:EquationforEntericFermentationEmissionsfromSwine(IPCC,2006)

.

Where:

CH4 =Methaneemissionsperday(kgCH4day‐1)

Population =Numberofswine(head)

0.00411 =DailyCH4emissionsfromeachanimal(kghead‐1day‐1)

Methodfor Estimating Swine GHG Emissions from Housing

Methane

TheIPCC(2006)Tier2methodisusedtoestimateCH4emissionswhenmanureisallowedtoaccumulatebelowtheanimalconfinementasdescribedbelow.

NitrousOxide

Nitrogenintake,retention,andexcretionestimatedusingequationsprovidedinASABED384.2.

IPCC(2006)Tier2approachforN2Ofrommanureinhousing.


5-56

Equation5‐16:ASABEApproachforEstimatingNitrogenExcretionfromSwine

Where:

Nex =Totalnitrogenexcretionperanimal(ganimal‐1)

Nintake =Nitrogenintakeperfinishedanimal(ganimal‐1)

Nretention =Nitrogenretainedperfinishedanimal(ganimal‐1)

Equation5‐17:ASABEApproachforEstimatingNitrogenExcretionfromGrow‐FinishPigs

. .

..

Where:



ADFIG =Averagedailyfeedintakeoverfinishingperiod(gday‐1)

CCP =Concentrationofcrudeproteinoftotal(wet)ration(%)

DOFG =Daysonfeedtofinishanimal(grow‐finishphase)(days)

BW =Final(market)bodyweight(kg)

DPF =Averagedressingpercent(yield)atfinalweight(%)

BW =Initialbodyweight(kg)

FFLPF =Averagefat‐freeleanpercentageatfinalweight(%)


5-57

aRecommendedvaluesare:350gday‐1forhighleangrowthcapacitypigs;325gday‐1forhigh‐moderateleangrowthcapacitypigs;and300gday‐1formoderateleangrowthcapacitypigs.

aAssumedtobe115days.bRecommendedvaluefromASABEis19.205kg.

Equation5‐18:ASABEApproachforEstimatingNitrogenExcretionfromWeaningPigs

.

.

Where:



ADFIG =Averagedailyfeedintakeoverfinishingperiod(gday‐1)

CCP =Concentrationofcrudeproteinoftotal(wet)ration(%)

DOFN =Daysonfeedtofinishanimal(nurseryphase)(days)

FFLGG =Averagefat‐freeleangainfrom20to120kg(gday‐1)a

BW =Finalbodyweightinnurseryphase(kg)

BW =Initialbodyweightinnurseryphase(kg)

Equation5‐19:ASABEApproachforEstimatingNitrogen ExcretionfromGestatingSows

. .

Where:



ADFIS =Averagedailyfeedintakeduringgestation(gday‐1)

CCP =Concentrationofcrudeprotein(%)

GL =Gestationperiodlength(days)a

GLTG =Gestationleantissuegain(kg)b

LITTER =Numberofpigsinlitter(head)


5-58

aRecommendedvaluefromASABEis‐4.20kg.

SomeofthenitrogenexcretedisvolatilizedasNH3,hence,theestimationofNH3lossesisnecessarytoestimateN2Oemissionsusinganitrogenbalanceapproach.TheNH3lostfrommanureinhousingisestimatedasafractionofNexaccordingtotherangesprovidedinTable5‐14.Arangeofvalueshasbeenprovidedforeachfacilitytype;thelowervaluesshouldbeusedduringthewinter,thehighervaluesshouldbeusedduringthesummer,andintermediatevaluesshouldbeusedforthespringandautumn.

Table5‐14:TypicalAmmoniaLossesfromSwineHousingFacilities(PercentofNex)

FacilityDescription %Loss FacilityDescription %LossRoofedfacility(flushedorscraped)Roofedfacility(dailyscrapeandhaul)

5‐15 Roofedfacility(beddedpack) 20‐40

Roofedfacility(shallowpitunderfloor) 10‐20Roofedfacility(deeppitunderfloor‐includesstorageloss) 30‐40


TheIPCC(2006)Tier2approachisusedforN2Oemissionsfrommanurestoredinhousing.TheestimationmethodisprovidedinEquation5‐8.TheN2OemissionfactorscanbefoundinTable5‐9.

TheremainingnitrogenexcretedthatisnotlostasN2OorvolatilizedasNH3inhousingthenentersmanurestorageandtreatment.Ifdataarenotavailabletotrackthenitrogenthatistransferredalongwiththemanuretomanurestorageandtreatment,thenitrogencanbeestimatedasdescribedinEquation5‐9.However,thisequationisoverestimatingthenitrogentransferringtomanurestorageandtreatmentassomenitrogenwillbelostinhousing.ThisremainingtotalnitrogenvalueisaninputintotheN2Oequationsformanurestoredortreated.

N2O‐NlossesfrommanurecollectedandremovedfromhousingcanbedeterminedfrommanurenitrogenusingequationsfromSection5.4ManureManagementfortheappropriatemanuremanagementsystem.NH3lossesfrommanurenitrogenremovedfromhousingcanbecalculatedusingthemethodologypresentedinAppendix5‐C.1and5‐C.3.

Equation5‐20:ASABEApproachforEstimatingNitrogenExcretionfromLactatingSows

. .

Where:



ADFILACT =Averagedailyfeedintakeduringlactation(gday‐1)

CCP =Concentrationofcrudeprotein(%)

LL =Lactationlength(daystoweaning)(days)

LLTG =Lactationleantissuegain(kg)a

LWEAN =Litterweightatweaning(kg)

LWBIRTH =Litterweightatbirth(kg)


5-59

5.3.4.2 RationaleforSelectingMethodforEstimatingEmissionsfromSwine

Milesetal.(2006)suggestthatarobustmodelforentericandhousingemissionswouldincludefactorssuchashousemanagement,animalsizeandage,pH,andmanuremoisture.Duetothecurrentdatalimitations,anNH3andGHGestimationmodelshouldminimallyincludenumberofanimals,excretamoisturecontent,dietproteinandfibercontent,andexcretapH.Thechallengeisthatthesecriteriamaynotbereadilyavailabletothefarmmanager.

Liuetal.(2011a)comparedliteraturevalueswithIPCCvaluesandconcludedthatthevariationofthemeasuredCH4andN2OhousingemissionrateshasnotbeenadequatelycapturedbytheIPCCapproaches.ForCH4emissions,thedifferencesbetweentheIPCC‐estimatedemissionratesandmeasuredvaluesweresignificantlyinfluencedbytypeofemissionsource,geographicregion,andmeasurementmethods.LargerdifferencesbetweenestimatedandmeasuredCH4emissionrateswereobservedinNorthAmericanstudiesthaninEuropeanstudies.InNorthAmericanstudies,theresultsofmeta‐analysisindicatedanoverestimationbytheIPCCapproachesforCH4emissionsfromlagoons(pooledrelativedifference:‐33.9%;95%CI:‐66.8%to‐0.01%),andthediscrepancybetweentheIPCC‐estimatedemissionsandthemeasuredvaluesoccurredmainlyatlowertemperatures.InEuropeanstudies,theresultsindicatedanoverestimationoftheIPCCapproachesinswinebuildingswithpitsystems.ForN2Oemissionsfromswineoperations,anoverallunderestimationoftheIPCCapproacheswasobservedinEuropeanstudiesbutnotinNorthAmericanstudies.InEuropeanstudies,thepooledN2Oemissionfactorsforswinebuildingswithpitsystemswas1.6%(95%CI,0.6%to2.7%),whiletheIPCCdefaultemissionfactorforpitsystemsis0.2%.LargeruncertaintieswereobservedformeasuredN2Oemissionsfrombeddingsystemsandfromstrawflowsystems.

InordertoconsideranalternativetotheIPCCapproach,awidevarietyofmodelsapplicabletoswineproductionfacilitieswereidentifiedandevaluated,including1)CARLivestock,2)ManureAndNutrientReductionEstimator(MANURE),3)COOLFarmTool,4)CarbonAccountingforLand

Model Evaluation Criteria for SwineProduction Systems

1. Themodelisbasedonwell‐establishedscientificallysoundrelationshipsbetweenfarmmanagementinputsandemissionsoutputs(process‐basedmodelormass‐balancemodelpreferable);

2. ThemodelisrelevanttoU.S.climateandswineproductionsystems;3. ThemodelcanestimateCH4,N2O,andNH3emissionsfromentericfermentationand

swinehousingsystems;4. Thereisflexibilityinthemodeltodescribetheproductionsystem(animals,feed,

housing,andin‐housemanuremanagement);5. Themodeliseasytouseandisdesignedtouseeasilyobtainablefarminformationto

determineemissionsestimates;6. Themodelincludessomemitigationstrategiesforreducingemissions,andproduces

realisticchangesinemissionsvalueswhenthesechangesaremadewithintheproductionsystem;

7. Thereistransparencyinthemodelcalculations,andtechnicalguidelinesareavailabletoelaboratethemethodologiesusedtoobtaintheemissionsestimates;

8. Themodelhasbeentested/validatedwithon‐farmdata;9. Themodelworksreliably(littletonoerrorsorprogramcrashes);and10. Themodelispubliclyavailableandaccessible.


5-60

Managers,5)FarmingEnterpriseGHGCalculator,6)CPLAN,and7)Holos.Thesemodelswereevaluatedby10criteria(seebox)todeterminetheirsuitabilityforuseindeterminingemissionsestimatesforswineproductionfacilitiesintheUnitedStates.Twoofthesecriteriawereconsideredtobecritical,inthatiftheywerenotmetbythemodel,theycouldnotbeconsideredforuse(i.e.,themodelhadtoberelevanttoU.S.climateandswineproductionsystemsandhadtobepubliclyavailable).

TheHolosmodelconsidereddiet(standard,lowcrudeprotein,orhigh‐digestibilityfeeds)andmanurehandlingoptions(anaerobicdigestion,coveredoruncoveredslurrystorage,deeppit,orsolidstorage).Inaddition,theHolosmodelprovidedanestimateofuncertaintyforthemodeloutput.TheMANUREmodel(WRI,2009)collectedthemostcomprehensivedataandallowedforeasycomparisonoftheimpactofchangesinmanurehandlinganduseonemissionsofNH3,N2O(directandindirect),andCH4.Ontheanimalside,MANUREbaseditscalculationssolelyonanimalnumbers;feedingwasnotconsidered.Theothermodelsconsidered,whilemeetingminimumcriteria,lackedanyimprovementsovertheIPCCapproach.Consequently,theIPCCmethodwasselected(i.e.,HolosutilizestheIPCCTier1approachforhousing)withnitrogenexcretionestimatedusingASABEequationsthataccountfordiets.

5.3.5 HousingEmissionsfromPoultryProductionSystems

MeatBirdsGreenhousegasemissionswithinthefarmboundaryofabroilerchickenfarmwilloriginatealmostexclusivelyfromtheanimalhousing,whichalsoservesasthestoragelocationformanure.Liuetal.(2011a)reportedthatfora20‐weekgrow‐outofturkeysonlitter,averagedailyN2Oemissionswere0.045g(kgbodyweight)‐1,anddailyCH4emissionswere0.08g(kgbodyweight)‐1.EmissionsourcesexternaltothehousingincludeGHGemissionsfromfarmvehicles.Ifahouseiscleanedordecaked(removalofthetop,crustedportionofthelitter)andstoredonthefarm,GHGandNH3productionandemissionscouldoccur;Appendix5‐CprovidesfurtherdiscussiononNH3emissionsfromhousing.Practicestodecakeandthetimingoflandapplicationofcakeandlittervaryfromsitetositeandmayormaynotincludefurthercomposting.

LayingHensGreenhousegasemissionswithinthefarmboundaryofaneggfarmmayoriginatefromthehousingorthemanurestoragelocation.EmissionsourcesexternaltothehousingincludeGHGemissionsfromfarmvehicles.Externaltothefarmitself,GHGemissionsresultfromlandapplicationoflitterorstockpilingofthelitterinfieldspriortolandapplication.

Layinghenhousingsystemswithoutlitterwouldlikelyexhibitgreateremissionsthanlittersystems,butcomparisonofestimatesaresparse.Layinghenhousestypicallystoreexcretainabasementormaymoveexcretaoutofthehousefrequently(dailyormoreoften);thiswouldrelocateemissionstoastorageshedratherthanchangethecumulativeemissionsunlesssomeformofprocessing(drying)tookplacepriortostorage.Lietal.(2010)reporteddailyCH4emissionsof39.3to45.4mghen‐1andN2Oemissionsof58.6mghen‐1(henbodyweightaverage=1.9kg)inabasement‐typesystem.Thiscomparestoalittersystemfora20‐weekgrow‐outofturkeyswhereaveragedailyN2Oemissionswere0.045gkg‐1bodyweightanddailyCH4emissionswere0.08gkg‐1bodyweight(Liuetal.,2011a).Basedonthecomparisonofthesetwostudies,differencesinGHGemissionsfromdrylittersystemsandwetter,stackedlayinghensystemswouldbeexpected.

ManagementpracticestoreducelittermoistureofferthemostpromiseforreducingemissionsofCH4andN2O.Quantitativeestimatesofhowemissionsvarywithlittermoisturearenotavailable,butwouldlikelyfollowsimilardynamicsassoilmoisturecontent.Reuseoflitteranddecaking


5-61

proceduresmightalsobeusedasstrategiestoreduceemissionsinthefuture.However,dataarenotavailableatpresenttouseaspartofasystemsmodel.

Ammonia Emissions in Poultry Housing

Asmentionedearlier,ammoniaisnotagreenhousegas,however,ammoniaemissionsareestimatedaspartofthenitrogenbalanceapproach.Meatbirdsaretypicallyraisedinlittersystems.Littertemperature,pH,andmoisture,alongwiththeammoniumcontentandhouseventilationratearerecognizedasmajorfactorscontrollingNH3lossfrombroilerlitter(ElliotandCollins,1982;Carretal.,1990;Mooreetal.,2010).Thereareseasonalvariationsinemissions,withlossestendingtobegreaterinsummer(warmermonths)thaninwinter(Coufaletal.,2006).Birdage/sizecanaffectlittertemperature,whichmayinfluenceseasonaleffectsonemissions(Milesetal.,2008).Inaddition,theformationofcakeinthehousecanhavealargeimpactonemissions.Milesetal.(2008)reportedthatextremelycakedareasofthehousehadvirtuallynofluxesofNH3.AreasoflitterwhereanaerobicconditionsdevelopsuppressNH3formationandrelease(Carretal.,1990).Mooreetal.(2011)determinedthatNH3emissionsfrombroilerhousesaveraged37.5gbird‐1,or14.5gkgbirdmarketed‐1(50‐dayoldbirds).Thesameauthorsestimatedthatofthetotalnitrogenoutputfromtypicalbroilerhouses,approximately22percentcanbeassociatedwithNH3emissions,56percentfromharvestedbirds,and21percentfromlitterpluscake.Theadditionofaluminumsulfate(alum)atarateequivalenttofiveto10percentbyweight(alum/manure)reducesNH3emissionfrombroilerhousesby70percent(Mooreetal.,2000)andresultsinheaverbirds,betterfeedconversion,andlowermortality(Moore,2013).EmissionsofN2OandCH4aredependentuponlitterconditionsthatfavorananaerobicenvironment.LimiteddataareavailabledocumentinglittermoisturecontenteffectsonN2OandCH4emissions.Milesetal.(2011)demonstratedthatincrementalincreasesinlittermoisturecontentincreasedNH3volatilization.Similarly,CabreraandChiang(1994)demonstratedarangeinNH3volatilizationof32percentto139percentofinitialammoniumcontentaslitterwatercontentincreased.LittertemperatureisanotherfactorthatmayinfluenceGHGemissions.Milesetal.(2006)demonstratedthatlittertemperatureaffectedNH3flux,butthestudydidnotmeasureothergases.Milesetal.(2011)observedthatorganicbeddingmaterialsgeneratedtheleastamountofNH3attheoriginalmoisturecontentwhencomparedwiththeinorganicmaterials.Theinfluenceofbeddingmaterialatincreasedmoisturelevelswasnotclearacrossthetreatmentstested.ButthefindingssuggestthatchoiceofbeddingmaterialmayalsoinfluenceN2Oand/orCH4emissionsandcouldpotentiallybeusedasamitigationstrategy.


5-62

5.3.5.1 MethodforEstimatingEmissionsfromPoultryProductionSystems

NitrousOxideandAmmoniaEmissionsfromPoultryHousingToestimatenitrogenlossesfromhousing,theamountofnitrogenexcreted(Nex)byeachanimalcategoryisfirstestimated.Equation5‐22andEquation5‐23aretheequationsrecommendedbytheAmericanSocietyofAgriculturalEngineers(ASABE)forestimatingNexfrombroilers,turkeys,ducks,andlayinghens.

Methodfor Estimating Emissions from Poultry Production Systems

Methane

IPCCTier1approach,utilizingbarncapacityandmanureCH4emissionsfactorsperpoultrytype.

IPCCemissionfactorforpoultryentericCH4productionis0.Emissionsfromhindgutfermentationaresmallandgenerallyconsideredpartofhousingemissions.

NitrousOxide

NitrogenexcretionestimatedusingequationsprovidedinASABED384.2. IPCC(2006)Tier2approachforN2Ofrommanureinhousing.

Equation5‐21:MethaneEmissionsfromPoultryHousing(IPCC,2006)

_

Where:

CH4 =Methaneemissionsperyear(kgCH4year‐1)

Rate =Manuremethaneemissions(kgCH4head‐1year‐1)

Barn_Capacity=Capacityofbarn(head)

Equation5‐22:ASABEApproachforEstimatingNitrogenExcretionfromBroilers,Turkeys,andDucks

.

Where:

Nex =Totalnitrogenexcretionperfinishedanimal(gN(finishedanimal)‐1)

FIx =Feedintakeperphase(gfeed(finishedanimal)‐1)

CCP‐X =Concentrationofcrudeproteinoftotalrationineachphase(gcrudeprotein(g(wet)feed)‐1)

NRF =Retentionfactorfornitrogen(fraction)


5-63

aDefaulteggweightis60gforlightlayerstrainsand63gforheavylayerstrains.bDefaultfractionis0.80.

TheNH3lostfrommanureformeatandegg‐producingbirdsisestimatedasafractionofNex.KoelschandStowell(2005)provideestimatesonthetypicalNH3lossfromdifferenthousingfacilitiesasafractionofNex(seeTable5‐15).Arangeofvalueshasbeenprovidedforeachfacilitytype;thelowervaluesshouldbeusedduringthewinter,thehighervaluesshouldbeusedduringthesummer,andintermediatevaluesshouldbeusedforthespringandautumn.

Table5‐15:TypicalAmmoniaLossesfromPoultryHousingFacilities(PercentofNex)

FacilityDescriptionApplicableSpecies %Loss FacilityDescription

ApplicableSpecies %Loss

Roofedfacility(litter)Meat

producingbirds

25‐50Roofedfacility(stackedmanureunderfloor‐includesstorageloss)

Egg‐producingbirds

25‐50


N2O can also be lost from the excreted nitrogen. A quantitative method for estimating N2O emissions from solid manure is the IPCC Tier 2 approach, which is also used for the U.S. Greenhouse Gas Inventory (Equation 5-8). This estimation method is the same as the method present in the Temporary Stack and Long-Term Stockpile and the Composting sections (see sections 5.4.1 and 5.4.2 for more details). The N2O emission factors for poultry manure in housing is 0.001 (kg N2O-N/ kg N) for poultry manure with or without bedding IPCC (2006).

TheremainingnitrogenexcretedthatisnotvolatilizedasNH3orlostasN2Oinhousingthenentersmanurestorageandtreatment.Ifdataarenotavailabletotrackthenitrogenthatistransferredalongwiththemanuretomanurestorageandtreatment,thenitrogencanbeestimatedasdescribedinEquation5‐9.However,thisequationisoverestimatingthenitrogentransferringtomanurestorageandtreatmentassomenitrogenwillbelostinhousing.ThisremainingtotalnitrogenvalueisaninputintotheN2Oequationsformanurestoredortreated.

5.3.5.2 RationaleforSelectingMethodforEstimatingEmissionsfromPoultryProductionSystems

Milesetal.(2006)suggestthatarobustmodelwouldincludefactorssuchashousemanagement,birdsizeandage,cakemanagement,pH,andlittermoisture.Duetocurrentdatalimitations,anNH3andGHGestimationmodelshouldminimallyincludenumberofanimals,litter/excretamoisturecontent,dietaryproteinandfibercontent,andlitter/excretapH.Avarietyofmodelsapplicableto

Equation5‐23:ASABEApproachforEstimatingNitrogenExcretionfromLayingHens

..

Where:


FI =Feedintake(gfeed(finishedanimal)‐1)

CCP =Concentrationofcrudeproteinoftotalration(gcrudeprotein(g(wet)feed)‐1)

Egg =Eggweighta(g)

Egg =Fractionofeggsproducedeachdayb(eggshen‐1day‐1)


5-64

poultryproductionfacilitieswereidentifiedandevaluated,includingCarbonAccountingforLandManagers;CFFCarbonCalculator;CPLAN;and4)Holos.Thesemodelswereevaluatedwithrespectto10criteria(seebox)todeterminetheirsuitabilityforuseindeterminingemissionsestimatesforpoultryproductionfacilitiesintheUnitedStates.

Twoofthesecriteriawereconsideredtobecritical,inthatiftheywerenotmetbythemodel,theycouldnotbeconsideredforuse(i.e.,themodelhadtoberelevanttoU.S.climateandpoultryproductionsystemsandhadtobepubliclyavailable).TheHolosmodeldidconsiderwetordrymanurehandlingforlayinghenoperations.Forallpoultrytypes,theCarbonAccountingforLandManagersmodelrequestedinformationrelatedtoburningofmanureandtimebirdsspendinafree‐rangesystem.Thisinformationwasthenusedtocalculatethemassofmanureavailablefordirectandindirectemissions.Nomodelrequestedinformationondietorin‐houselittermanagementpractices.ForCH4emissions,onlytheHolosmodelprovidedanestimateofconfidenceofmodeloutput.SpecifictoestimatesofpoultrymanureCH4emissions,themodelhadanuncertaintyunder20percentforbroilers,turkeys,layersinwetmanurehandlingsystems,andlayersindrymanurehandlingsystems.Consequently,theIPCCmethodwasselected(i.e.,HolosutilizestheIPCCTier1approachforhousing).ForN2Oemissions,theIPCCTier2wasusedwithnitrogenexcretionestimatedusingASABEequationsthataccountfordiets.

5.3.6 EntericFermentationandHousingEmissionsfromOtherAnimals

AlthoughthemajorityofemissionsfromlivestockintheUnitedStatesarefromcattle,sheep,swine,andpoultry,emissionsfromotheranimalscanalsobeimportanttoconsider,particularlyattheentitylevel.Overall,populationsoftheanimalsdiscussedinthissection(goats,Americanbison,llamas,alpacas,andmanagedwildlife)aremuchfewerthanthoseoftheanimalsdiscussedinpriorsections.However,theavailabilityofresearchonemissionsfromtheseanimalsallowsustoexplorethematleastatanintroductorylevel.Attheentitylevel,populationsoftheseanimalsmaybesignificantenoughtowarrantcalculatingtheiremissions.ThisreportrecommendsmethodsforestimatingCH4emissionsfromgoatsandAmericanbison(Equation5‐24andEquation5‐25).

Model Evaluation Criteria for Poultry Production Systems

1. Themodelisbasedonwell‐establishedscientificallysoundrelationshipsbetweenfarmmanagementinputsandemissionsoutputs(process‐basedmodelormass‐balancemodelpreferable).

2. ThemodelisrelevanttoU.S.climateandproductionsystems.3. ThemodelcanestimateCH4,N2O,andNH3emissionsfrompoultryhousingsystems.4. Thereisflexibilityinthemodeltodescribetheproductionsystem(animals,feed,

housing,andin‐housemanuremanagement).5. Themodeliseasytouseandisdesignedtouseeasilyobtainablefarminformationto

determineemissionsestimates.6. Themodelincludessomemitigationstrategiesforreducingemissionsandproduces

realisticchangesinemissionsvalueswhenthesechangesaremadewithintheproductionsystem.

7. Thereistransparencyinthemodelcalculations,andtechnicalguidelinesareavailabletoelaboratethemethodologiesusedtoobtaintheemissionsestimates.

8. Themodelhasbeentested/validatedwithon‐farmdata.9. Themodelworksreliably(littletonoerrorsorprogramcrashes).10. Themodelispubliclyavailableandaccessible.


5-65

5.3.6.1 Goats

EntericemissionsfromgoatproductionsystemswereestimatedbyU.S.EPA(U.S.EPA,2011)usingIPCC(2006)methodstobe16GgCH4(ofatotalof6,655Gg).EmissionsofmanureCH4andN2OfromgoatproductionweremadeusingIPCC(2006)methods.Goatswereassociatedwith1GgofmanureCH4(ofatotalof2,356Gg)andlessthan0.5GgofN2O.

TheimpactofdietonJapanesegoatentericCH4emissionswasmeasuredbyBhattaetal.(2007).Goatsfedarangeofdietsfrom100percentforageto80percentconcentrateproducedfrom16.4to22gCH4day‐1(5.0to8.2percentofGEI).

TheIPCC(2006)Tier1equation,presentedinEquation5‐24,forestimatingentericfermentationemissionsfromgoatsisthebestoptionforcalculatingemissionsattheentitylevel.

5.3.6.2 AmericanBison,Llamas,Alpacas,andManagedWildlife

Galbraithetal.(1998)measuredentericCH4fromgrowingbison(n=5),wapiti(n=5),andwhite‐taileddeer(n=8)fedalfalfapelletsinthewinter‐spring(February‐March)andspring(April‐May)usingrespirationcalorimetrychambers.Thebisonproducedanaverageof86.4gday‐1(6.6percentGEI),thewapiti,62.1gday‐1(5.2percentGEI),andthedeer23.6gday‐1CH4(3.3percentGEI).Usingadetailedmethodofcalculationtoestimatehistoricalbisonemissions,KelliherandClark(2010)estimatedthatgrazingbisonwouldproduce72kgCH4year‐1or197gCH4day‐1.Hristov(2012)estimatedpresentdaybisonproduce21gCH4(kgDMI)‐1day‐1,eatapproximately12.8kgDMday‐1,andproduce268gCH4day‐1.Thedifferencesbetweentheseestimatesaredifferencesinanimalweights,DMI,limitedmeasurementsofbisonemissions,andassumedCH4conversionfactors.TheU.S.EPAusesIPCCTier1methodologiestoestimatebisonemissions,andcurrentlyTier1isthebestoptiontoestimateentericemissions.

TheIPCC(2006)Tier1equationforestimatingentericfermentationemissionsfromAmericanbisonisbasedontheemissionfactorforbuffaloandhasbeenmodifiedasrecommendedbyIPCCtoaccountforaverageweightasseeninEquation5‐25.

Equation5‐24:Tier1EquationforCalculatingMethaneEmissionsfromGoats

Where:

CH4 =Methaneemissionsperday(kgCH4day‐1)

Pop =Populationofgoats(head)

EFG =Emissionfactorforgoats(0.0137kgCH4head‐1day‐1)


5-66

TheNewZealandMinistryfortheEnvironment(2010)usesafactorof6.4percentofGEItopredictentericCH4emissionsfromfarmedreddeerandprojectsanemissionrateperyearof23.7kgCH4

head‐1year‐1.Deerarealsoestimatedtoexcrete31.0kgNhead‐1year‐1contributingtowardN2Oproduction.ThevaluesusedtomakethesecalculationsarefrommeasurementsofdeerCH4emissionsusingtheSF6tracermethod.Elk,white‐tailed,andmuledeerentericemissionswereestimatedbyHristov(2012)tobe86.4,16,17gCH4head‐1day‐1respectively.IPCCTier1istherecommendedmethodbywhichtheseemissionsshouldbeestimated.

Adultllamasfedoathayinastudydesignedtodefineenergyrequirementswerefoundtolose7.1percentofGEIasentericCH4(Carmeanetal.,1992).Pinares‐Patinoetal.(2003)comparedentericCH4emissionsmeasuredwithrespirationcalorimetrychambersfromalpacaandsheepfedalfalfadietsandfoundthealpacaproduced14.9gCH4day‐1(5.1percentofGEI)andthesheepproduced18.8gCH4day‐1(4.7percentofGEI).Whengrazingaperennialryegrass/whitecloverpasture,thealpacaproduced22.6gCH4day‐1(9.4percentGEI)comparedto31.1gCH4day‐1(7.5percentGEI)forsheep.TheauthorsattributethehighconversionofGEItoCH4fromthealpacatograzingselectivityonpasture;thealpacawereobservedtoselect“morestructuralplantparts.”

5.3.7 FactorsAffectingEntericFermentationEmissions

AnumberoffactorsmayinfluenceentericfermentationandresultingCH4emissions.Athoroughreviewofsuchfactorsisoutsidethescopeofthisdocument,butkeyfactorshavebeenreviewedbyothers(Montenyetal.;(2006),Beaucheminetal.;(2008),Eckardetal.;(2010),andMartinetal.;(2010))andarediscussedbrieflybelow.

Benchaaretal.(2001)usedtherumendigestionmodelofDijkstraetal.(1992),asmodifiedbyBenchaaretal.(1998),andtheCH4predictionsystemofBaldwin(1995)toestimatetheeffectsofdietarymodificationsontheentericCH4productionofa500kgdairycow.ThemodelpredictedentericCH4productionbasedonaruminalHbalance.Inputsintothemodelincludedthefollowing:dailyDMI;chemicalcompositionofthediet;solubilityanddegradabilityofproteinandstarchinthediet;degradationratesofprotein,starch,andNDF;ruminalvolume;andfractionalpassageratesofsolidsandliquidfractionsfromtherumen.ValuesmodifiedinthesimulationswereDMI,dietaryforage,concentrateratio,starchavailability(barleyvs.corn),stageofmaturityofforage,formofforage(hayorsilage),particlesizeofalfalfa,andammonizationofcerealstraw.ThemodeledeffectsofdietarychangesonentericCH4emissionsindietsfedtodairycowsarepresentedinTable5‐16.

Equation5‐25:Tier1EquationforCalculatingMethaneEmissionsfromAmericanBison

Where:

CH4 =Methaneemissionsperday(kgCH4head‐1day‐1)

Pop =PopulationofAmericanbison(head)

EFAB=EmissionfactorforAmericanbison(kgCH4head‐1day‐1)

EFABistheIPCCemissionfactorforbuffalo(0.15kgCH4head‐1day‐1),adjustedforAmericanbisonbasedontheratioofliveweightsofAmericanbison(513kg)tobuffalo(300kg)tothe0.75power.

.


5-67

TherearemanyfactorsthataffectentericCH4emissionsbutthemostcriticalfactorsarethelevelofdrymatterintake,thecompositionofthediet,andthedigestibilityofthedrymatter,asillustratedinTable5‐16.

Table5‐16:SummaryofEffectsofVariousDietaryStrategiesonEntericCH4ProductioninDairyCowsusingModeledSimulations

StrategyCH4Variation(perunitofGEI)

CH4Variation(perunitofDE)

IncreasingDMI ‐9to‐23% ‐7to‐17%Increasingconcentrateproportioninthediet ‐31% ‐40%Switchingfromfibrousconcentratetostarchyconcentrate ‐24% ‐22%Increasedforagematurity +15% ‐15%Alfalfavs.timothyhay +28% ‐21%Methodofforagepreservation(ensiledvsdried) ‐32% ‐28%Increasedforageprocessing(smallerparticlesize) ‐21% ‐13%Ammoniatedtreatmentofpoorqualityforage(straw)a x5 x2Proteinsupplementationofpoorqualityforage(straw) ×3 ×1.5

Source:Benchaaretal.,(2001),Table12.aEffectsareduetosignificantincreaseinhaydigestibilitywithnochangeinDMintake.

DietaryFat:ManystudieshavedemonstratedthatsupplementalfatcandecreaseentericCH4emissionsinruminants.Inareviewofstudies,Beaucheminetal.(2008)notedthatentericCH4emissions(g[kgDMI]‐1)decreasedbyapproximately5.6percentforeachonepercentincreaseinfataddedtothediet.Inalargerreview,Martinetal.(2010)reportedadecreaseof3.8percent(g[kgDMI]‐1)witheachonepercentadditionoffat.Lovettetal.(2003)reportedthattotaldailyemissionsdecreasedfrom0.19to0.12kgCH4head‐1(reportedas260to172LCH4head‐1)(6.6and4.8percentofGEI)fromsteersfeddietscontaining0or350gofcoconutoil,respectively.Thiseffectwasconsistentregardlessofdietaryforageconcentration(65,40,and10percentofDM).

AlthoughaddedfatmayreduceentericCH4emissions,ruminantshavealowtolerancefordietaryfat.Thus,totalfatlevelinthedietmustbemaintainedbeloweightpercentofdietaryDM.Somesourcesoffatappeartohavesomeprotectionagainstbiohydrogenationbyruminalmicrobesandthusmaybebettertolerated(Corriganetal.,2009;VanderPoletal.,2009).

GrainSource,GrainProcessing,StarchAvailability:GrainsourceandgrainprocessingmethodcanalsoaffectentericCH4losses.Ingeneral,thegreatertheruminalstarchdigestibility,thelowertheentericCH4emissions.Atconstantenergyintake(2xmaintenance),Halesetal.(2012)reportedapproximately20percentlower(2.5vs.3.0percentofGEI)entericCH4emissionincattlefedtypicalhigh‐concentrate(75percentcorn)steamflakedcorn(SFC)basedfinishingdietsthaninsteersfeddry‐rolledcorn(DRC)basedfinishingdiets.BasedontherumenstoichiometryofWolin(1960),ZinnandBarajas(1997)estimatedthatCH4productionperunitofglucoseequivalentfermentedintherumenalsodecreasedwithmoreintensivegrainprocessing(i.e.,coarse,medium,orfineflakes).Similarresponseswerenotedwiththefeedingofhigh‐moisturecorncomparedwithDRC(Archibequeetal.,2006).Somewhatincontrast,BeaucheminandMcGinn(2005)reportedlowerentericCH4emissionsfromfeedlotcattlefedDRC‐baseddiets(2.81percentofGEI)thanfromcattlefedsteam‐rolledbarley‐baseddiets(4.03percentofGEI),possiblytheresultoflowerruminalpHonthecorn‐baseddiet(5.7vs.6.2,respectively;(VanKesselandRussell,1996)and/orhigherNDFinthebarleydiet.EntericCH4emissionswere38percent(barley)to65percent(corn)lowerinhigh‐concentrate(ninepercentsilage)finishingdietsthanongrower(70percentsilage)diets.


5-68

FeedingCoproductIngredients:Distillersgrainswithsolubles(DGS)andothercoproductsofthemillingandethanolindustriesarewidelyusedascattlefeeds.Theeffectsoffeeding30to35percentDGS(DMbasis)onentericCH4emissionhavebeenvariable,rangingfromasignificantdecreaseof25to30percent(McGinnetal.,2009)tonoeffect(Halesetal.,2012),toanincrease(Halesetal.,2013).Thesedifferingresultswereprobablyduetodifferencesinforageandfatintake.InthestudybyMcGinnetal.(2009)thedietcontained65percentsilage,anddietaryfatintakeincreasedbyapproximatelythreepercentageunits8whendriedDGSwereaddedtothediet.Incontrast,Halesetal.(2012;2013)feddietsthatcontainedonly10percentforageandwereequalintotalfatconcentration.

RoughageConcentrationandForm:TheconcentrationandformofroughageinthedietwillaffectbothentericandmanureCH4production(Halesetal.,2014).Usingaruminalvolatilefattyacids(VFA)stoichiometrymodel,Dijkstraetal.(2007)suggestedthatCH4lossesfromcarbohydratessubstrates(gkg‐1substrate)inaconcentratedietwithruminalpHvariationandapHof6.5were2.11,3.18,3.38,and3.10forstarch,solublesugars,hemicellulose,andcellulose,respectively.Similarly,withdairycows,MoeandTyrrell(1979)reportedthatentericCH4productionperunitcarbohydratedigestedwasthreetimesgreaterforcellulosethanforhemicellulose.Aguerreetal.(2011)foundthatlactatingdairycattleemittedmoreCH4whentheforage:concentrateratiowaschangedfrom47:53to68:32,0.54kgCH4day‐1vs.0.65kgCH4day‐1respectively.

Ingeneral,astheconcentrationofforageinthedietincreases,entericCH4productionincreasesandthequantityofvolatilesolidsexcretedincreases.Usingamicrometeorologicalmassdifferencemethod,Harperetal.(1999)reportedCH4emissionsof230ganimal‐1daily(7.7to8.1percentofGEI)infeedercattleonpasture,butonly70ghead‐1daily(1.9to2.2percentofGEI)incattlefedhigh‐concentratediets.MeasuredCH4lossesforpasturecattlewerehigherthanvaluespredictedusingtheIPCC(1997;2006)CH4conversionfactors(MCForYm),orAustralianmethodology(NGGIC,1996).Incontrast,measuredCH4lossesforfeedlotcattlewereabout67percentofthoseestimatedusingtheIPCC(2006)YmofthreepercentofGEIortheAustralianmethodology(NGGIC,1996),butweresimilartovaluesreportedbyBranineandJohnson(1990),BlaxterandWainman(1964),andHalesetal.(2012;2013;Halesetal.,2014).

EntericfermentationoftropicalgrassesandlegumesmayalsobedifferentthanpredictedbyIPCCornationalGHGinventorymethods.KennedyandCharmley(2012)measuredentericCH4productionofcattlefedAustraliantropicalgrassesandlegumestobe5.0to7.2percentofGEintakewhichissimilartoIPCC(2006)Tier2estimates(5.5to7.5percentofGEintake)ofcattlefedforagedietsbutsomewhatlowerthantheAustralianNationalGreenhouseAccountsNationalInventoryReport(2007)of8.7to9.6percentofGEintake.

BlaxterandWainman(1964)comparedtheeffectsoffeedingdietswithsixvaryinghay:flakedcornratios(100:0,80:20,60:40,40:60,20:80,5:95)onentericCH4emissionswhenfedattwotimesthemaintenancelevelofintake.CH4emissionsasapercentageofGEIincreasedslightlybetweenthe100:0diet(7.44percent)andthe60:40diet(8.17percent),thendecreasedtothe5:95diet(3.4percent).

InIreland,Lovettetal.(2003)reportedtotaldailyentericCH4emissionsof0.15,0.19,and0.12kghead‐1(reportedas207,270,and170Lhead‐1)forheifersfeddietscontaining65,40,and10percentforage(theremainderasconcentrate),respectively.AsapercentageofGEI,losseswere6.1,6.6,and4.4percent,respectively.

8Theterm“percentageunits”inthisdocumentisusedtorefertochangesindietsoremissionsthatarenotproportionaltotheirbaselines.Forexample,areductioninemissionsfromthreepercenttoonepercentisa2“percentageunit”reductionora67percentreduction.


5-69

Usingsteersfedall‐foragediets,Ominskietal.(2006)reportedthat,withintherangeofforagequalitiestested(alfalfa‐grasssilagecontaining61,53,51,or46percentNDF,DMbasis),entericCH4emissionsofsteers,asapercentageofGEI,werenotsignificantlyaffectedbyNDFcontent(5.1to5.9percent),althoughdailyCH4productiontendedtobehighestforthe53percentNDFdiet(0.12,0.15,0.13,and0.14kghead‐1day‐1,respectively).Similarly,usinggrazingsheep,MilanoandClark(2008)reportednoeffectofforagequality(ryegrass–52or47percentNDF,77or67percentorganicmatter[OM]digestibility)onentericCH4emissions.

AlthoughdietaryforagequalitymaysometimesnotaffectentericCH4emissions,itwillaffectforagedigestibilityandthusfecalexcretionofvolatilesolids.Thus,feedingmoredigestibleforagesorconcentratesmaydecreaseGHGemissionsfrommanure.

LevelofIntake:BlaxterandWainman(1964)comparedtheeffectsoffeedingsixdietsattwolevelsofintake.EntericCH4emissions,asapercentofGEI,were23percentgreaterinsteersfedatmaintenancethaninsteersfedat2Xmaintenance(8.1vs.6.6percentofGEI,respectively).However,inastudyevaluatingemissionsfromcattlefedryegrassdiets,MilanoandClark(2008)reportedthatasDMIincreasedfrom0.75percentofmaintenanceto2Xmaintenance,entericCH4emissions(gday‐1)increasedlinearly(r2=0.80to0.84).EmissionsasapercentageofGEIwerenotaffectedbyDMI,andrangedfrom4.9to9.5percentofGEI(15.9to30.4g[kgDMI]‐1).

Usingahigh‐forage(70percentbarleysilage)ormedium‐forage(30percentsilage)dietfedatlevelsfrom1Xtoapproximately1.8Xmaintenance,BeaucheminandMcGinn(2006b)notedthatentericCH4emissions,asapercentofGEI,decreasedbyapproximately0.77percentageunitsforeachunitincreaseinfeedintake(expressedasleveloffeedintakeabovemaintenance).ThiswaslessthantheestimateusingtheBlaxterandClapperton(1965)equation(0.93to1.28percentpercentageunits)orthe1.6percentageunitssuggestedbyJohnsonandJohnson(1995).

FeedAdditivesandGrowthPromoters:Cooprideretal.(2011)notedthatthedailyCH4andmanureN2Oproductionofcattlefedthrougha“natural”programwithnouseofantibiotics,ionophores,orgrowthpromotersweresimilartocattlefedinmoretraditionalsystemsthatusedanabolicimplantsanddietsthatcontainedionophoresandbeta‐agonists.However,typicalcattlehadgreateraveragedailyweightgain(1.85vs.1.35kgday‐1)andthustook42fewerdaystoreachthesameendpoint(596kgbodyweight[BW]).Thus,overall,cattlefedusingmoderngrowthtechnologieshad31percentlowerGHGemissionsperhead.CH4emissionskgofBWgain‐1was1.1kggreaterforthe“natural”cattle(5.02vs.3.92CO2‐eqkgBWgain‐1)thanthetraditionalcattle.

MonensindecreasesentericCH4emissionsinfinishingcattleby10to25percent(Tedeschietal.,2003;McGinnetal.,2004).However,infeedlotcattletheeffectsappeartobetransitory,lastingfor30daysorless(Guanetal.,2006).Incontrast,Odongoetal.(2007)reportedthatmonensin(24ppm)indairydietsdecreasedentericCH4byseventoninepercentforuptosixmonths.Waghornetal.(2008)foundnoeffectofmonensincontrolled‐releasecapsulesonCH4productionofpasture‐feddairycows,andHamiltonetal.(2010)alsofoundnochangeinentericCH4productionfrommonensinfedtodairycowsofferedatotalmixedration.

AnumberofstudieshavedemonstratedthatavarietyofhalogenatedanalogueshavethepotentialtodramaticallydecreaseruminalCH4production(Johnson,1972;Treietal.,1972;Johnson,1974;ColeandMcCroskey,1975;TomkinsandHunter,2004;Tomkinsetal.,2009).Ingeneraltheeffectwasgreaterincattlefedhigh‐foragedietsthanincattlefedhigh‐concentratediets.WhenCH4lossesweredramaticallyreduced,asignificantquantityofhydrogencouldbelost(onetotwopercentofGEI)viaeructation,suggestinganalternativeelectronsinkisalsoneeded.Ingeneral,thecompoundsdidnotimproveproductionefficiencysignificantly.Inaddition,thepotentialtoxicityofthesecompoundsmadethemimpracticalforroutineuse.


5-70

Anumberofnitrocompounds(nitropropanol,nitroethane,nitroethanol)havealsosignificantlydecreasedruminalCH4productioninvitro(Andersonetal.,2003),withaconcomitantincreaseinhydrogenproduction/release.Theeffectappearedtobeenhancedwhenanitratereducingbacteriumwasaddedtotheculture(AndersonandRasmussen,1998).

SeveralstudieshavesuggestedthatfeedingofcondensedtanninscandecreaseentericCH4productionby13to16percent;eitherthroughadirecttoxiceffectonruminalmethanogensorindirectlyviaadecreaseinfeedintakeanddietdigestibility(Eckardetal.,2010).Tanninsmayalsoshiftnitrogenexcretionawayfromurinetofecesandinhibitureaseactivityinfeces,whichcouldpotentiallydecreaseNH3andN2Oemissionsfrommanure(Powelletal.,2009;Powelletal.,2011).

Feedingyeastcultures,enzymes,dicarboxylicacids(fumarate,malate,acrylate),andplantsecondarycompounds,suchassaponins,maydecreaseentericCH4emissionsundersomefeedingconditions(McGinnetal.,2004;BeaucheminandMcGinn,2006a;Ungerfeldetal.,2007;Beaucheminetal.,2008;Eckardetal.,2010;Martinetal.,2010).

NovelMicroorganismsandtheirProducts:KlieveandHegarty(1999)notedthatentericCH4productionmaybebiocontrolleddirectlybyuseofvirusesandbacteriocins.Leeetal.(2002)reportedthatabacteriocin(BovicinHC5)fromStreptococcusbovisreducedinvitroCH4productionbyupto50percent.Itappeared,thatincontrasttoresultswithmonensin,theruminalmicroorganismsdidnotadapttothebacteriocin.

AustralianresearchershavesuggestedthatvaccinatingagainstmethanogenscandecreaseCH4emissions.However,theresultshavenotbeenconsistent(Wrightetal.,2004;Eckardetal.,2010)becauseefficacyisdependentonthespecificmethanogenpopulationandthatisdependentondiet,location,andotherfactors.

Genetics:Aspreviouslynoted,severalstudieshavesuggestedthatcattleselectedforlowerRFI(i.e.,increasedfeeduseefficiency)tendtohavelowerruminalentericCH4production(Nkrumahetal.,2006;Hegartyetal.,2007),althoughtheeffectmaydependonstageofproduction(lactationvs.dryandpregnant)and/orqualityofthedietconsumed(Jonesetal.,2011).RFIismoderatelyheritable(0.28to0.58)(Mooreetal.,2009),thusitmightbepossibletogeneticallyselectforanimalswithlowerentericCH4production.However,FreetlyandBrown‐Brandl(2013)foundhigherCH4emissionsfrommoreefficientanimals.Thus,moreinformationisneededtodefineunderwhatconditionsCH4emissionsarerelatedtofeedefficiencyortogenetics.

FactorsAffectingEmissionsfromSheepSheep,likecattle,areruminantanimalsandthusthesamedietaryfactorswillpositivelyornegativelyaffectemissionsfromentericfermentation.

FactorsAffectingEmissionsfromSwineDietarymodificationscaneffectivelyreducenitrogenexcretionsandmitigateairemissions(especiallyNH3,aprecursorforN2O)fromlivestockoperations(Suttonetal.,1996;Canhetal.,1998b).FeedingstrategiestoreducenitrogenexcretionsincludereducedCPdietssupplementedwithsyntheticaminoacids(AA)(Panettaetal.,2006),andmodifyingthedietaryelectrolytestoreduceurinarypH(Canhetal.,1998a).Inbothhogandpoultryoperations,reductionsinNH3emissionshavebeenreportedbysupplementingwithAAandreducingCPindiets.

ReducingdietaryCPcontenthasbeenshowntobeaneffectivewaytoreducetheamountofnitrogenexcreted(Lenis,1993;HartungandPhillips,1994).ThiscanbeachievedwithoutanynegativeeffectonanimalperformancebysupplementingwithanimprovedsyntheticAAbalance,resultinginareductionofexcessCPexcreted(Canhetal.,1998b;Ferketetal.,2002).InU.S.‐typediets(corn‐soybeanmealbased)themostlimitingaminoacidsareLysine,Methionine,Threonine,


5-71

andTryptophan,followedbyIsoleucine,Valine,andHistidine(Outor‐Monteiroetal.,2010).Suttonetal.(1996)reportedthatnitrogenexcretiondecreasedby28percentwhendietCPcontentdecreasedfrom13percentto10percent(corn‐soybeanmeal)forgrowing‐finishingpigdietssupplementedwithLys,Met,Thr,andTrp.SeveralstudiesreportedreductionsinnitrogenexcretionandsubsequentdecreasesinNH3emissionsinnon‐ruminants(swineandpoultry)(HartungandPhillips,1994;Canhetal.,1997;Canhetal.,1998a;Canhetal.,1998b;Hayesetal.,2004).Powersetal.(2007)observedthat,asaresultoffeedingreducedCPdietswithincreasedamountsofsyntheticAA,NH3emissionswerereducedby22percent(threeAA)and48percent(fiveAA)comparedwiththecontroldietcontainingonlyoneAA,anddiethadnoeffectonpigperformance.

Canhetal.(1998b)andNdegwaetal.(2008)reportedthatsomenitrogenexcretioncouldbeshiftedfromurinetofecesbyincreasingdietaryfibercontent,orbyreducingdietarynitrogencontent,withnosignificantdifferencesinanimalperformanceorgrowth.Urinarynitrogenispredominantlyinorganicinnatureandfecalnitrogenismostlyorganic.TheconversionofureafromurinetoNH3isafastprocess,whileconversionoforganicnitrogentovolatileNH3infecesisaslowprocess.

ThereductioninNH3emissionassociatedwithlowerCPdietsnotonlycomesfromreductioninnitrogenexcretion,butalsofromlowermanurepH.Portejoieetal.(2004)reportedthatslurrypHdecreasedby1.3unitswhendietaryCPdecreasedfrom20to12percent,andslurryfrompigsfedthelowerCPdiethadahigherDMcontentandlowerTANandTKNcontents.Leetal.(2008),Hannietal.(2007),andCanhetal.(1998b)alsoreportedthatlowermanurepHresultedfromfeedinglowerCPindiets.Itshouldbenotedthatwaterintakewasoftenrestrictedinearlierstudies.

AarninkandVerstegen(2007)summarizedfourdietarystrategiestoreduceNH3emissions:1)loweringCPintakeincombinationwiththeadditionoflimitingAA;2)shiftingnitrogenexcretionfromurinetofecesbyincludingfermentablecarbohydratesinthediet;3)loweringurinarypHwiththeadditionofacidifyingsaltstothediet;and4)loweringfecespHwiththeinclusionoffermentablecarbohydratesinthediet.Theyclaimedthatbycombiningthesestrategies,NH3emissionsingrowing‐finishingpigscouldbereducedbyatotalof70percent.Toreduceodorfrompigmanure,Leetal.(2007)suggestthatdietarysulfur‐containingAAshouldbeminimizedtojustmeettherecommendedrequirements.

CurrentresearchhasconcentratedonfarmproductionefficiencyandreducingNH3emissions;littlehasfocusedonGHGemissionsmitigation(Bhattietal.,2005).BallandMöhn(2003)showedthatlowCPdietscanreducetotalGHGemissionsfromgrowingpigsby25to30percent(directlyfromtheanimalsaswellasfromthemanureafterexcretion)andfromsowsby10to15percent.Atakoraetal.(2003)reporteda27.3percentdecreaseinCH4emissionsinpigsfed16percentCP(supplementedwithAA)diets,comparedwith19.0percentCPdiets.Atakoraetal.(2004)reportedthattheCO2equivalentsemittedbyfinishingpigsandsowsfedwheat‐barley‐canoladietswerereducedby14.3to16.5percentwhenfeedingthereducedCP,AA‐supplementeddiets,andweresimilarforfinishingpigsandsows.Thereductionwasonly7.5percentwhenfeedingthecorn‐soybeanmeal‐basedreducedCPdiet.Misselbrooketal.(1998)foundthatCH4emissionsduringstoragewerelessatlowthanatahighdietaryCPcontent.TheemissionofCH4wassignificantlyrelatedtocontentofdrymatter,totalcarbon,andVFAinthemanure.Misselbrooketal.(1998)claimedthatthe50percentreductioninCH4emissionfromtheslurryobservedwhenpigswerefedthelowerCPdietwasprobablytheresultofthereducedvolatilefattyacids(VFA)contentoftheslurry,andCH4emissionsweremorecloselyrelatedtoVFAcontentthantototalcarboncontent.ThereappearstobeacloserelationshipbetweenfermentablecarbohydratesinthedietandCH4production(Kirchgessneretal.,1991).ManurepHalsoinfluencesCH4production.Kimetal.(2004)noteda14percentreductioninCH4emissionwhenidealpHwasreducedoneunitthroughaddition


5-72

ofacidogeniccalciumandphosphorussourcestopigdiets.IncreasingfermentablecarbohydratelevelsinthediettolowerthepHofmanure,withthegoalofreducingNH3emissions,mightincreaseCH4production(AarninkandVerstegen,2007).Canhetal.(1998a)observedthatforeach100‐gincreaseintheintakeofdietarynon‐starchpolysaccharide(NSP),theslurrypHdecreasedbyapproximately0.12unitsandtheNH3emissionfromslurrydecreasedby5.4percentwhendietaryNSPrangedfrom150to340gNSPkgDM‐1.

Feedingofdrieddistillersgrainswithsolubles(DDGS)hasbecomecommonpracticeintheswineindustry.Lietal.(2011)demonstratedthatfeedingdietscontaining20percentDDGSincreasedemissionsofCH4butnotN2OwhencomparedtocontroldietswithoutDDGS.ObservedincreasesinCH4emissionsapproximated18percent.Ammoniaemissionsresultingfromfeeding20percentDDGSwereeitherhigherorlowerthandietswithoutDDGS,dependingontheformoftracemineralsincludedinthediet.DietsincludinginorganicformsoftracemineralshadsevenpercentgreaterNH3emissions,whilefeedingorganicformsoftracemineralsdecreasedNH3emissionsalmost20percentcomparedtocontroldiets(Liuetal.,2011a).

Inarecentmeta‐analysis,Liuetal.(2011a)used32datapointsinasubgroupofstudiesthatincludeddietCPinformationtoanalyzetheeffectofdietCPonGHGemissions.Threefactors(dietCP,geographicregion,andswineproductionphase)wereconsideredintheregressionanalysis.DietCPwasnotasignificantfactor.EmissionsofCH4arepositivelycorrelatedwithdietcrudeproteininswineproduction,mostsignificantlyforlagoonandslurrystoragesystems(Liuetal.,2011a).Clarketal.(2005)determinedthatreducingdietaryCPmayactuallyincreaseCH4emissions,soresultsarevaried.IthadbeenexpectedthatalowerCPdietmayresultinlowernitrogenexcretion,andthusmightbeabletoreduceN2Oemissionsfrommanure.However,thishypothesiswasnotsupportedbytheresultsofthemeta‐analysis.

Dietformulationateachstageofthelifecycleinfluencesnutrientsexcretedinmanure,aswellasemissionsthatresultfromthatmanureduringstorageandpotentiallyfollowinglandapplication.Fromamodelingperspective,thefocusneedstobeonmanagementfactors,includingdietformulationandmanurehandlingpractices.

Feedefficiencyimprovementscanreduceemissionsthroughouttheentirefoodproductioncyclebyreducingtheamountoffeedneededformeatproduction,therebyreducinginputsintofeedproductionaswellasreducingmanurenutrientsthatmustbemanaged.Feedefficiencyistheproductofgeneticsandenvironment(management).Geneticdifferencesaredifficulttoassess,becausethisinformationisretainedbycompanies.Geneticimprovementsarenotinsignificantovertimeandmayinfactbealargercontributortogainsthanmanagement.However,fromamodelingperspective,thefocusneedstobeonmanagementfactors,includingdietformulationandin‐housemanure/litterpractices.FeedefficiencycouldbeamodelcomponentinthefutureoncemoredataontheimpactsoffeedefficiencyonGHGemissionsareavailable.

FactorsAffectingEmissionsfromMeatBirdsEmissionsofbothN2OandNH3canberestrictedbyreducingthelitternitrogencontentthroughdietmodification.Fergusonetal.(1998a;1998b)fedreduceddietaryproteindietstobroilerchickens.Althoughperformancewashinderedinbothstudies,NH3concentrationandlitternitrogencontentwerereducedsignificantlyasaresultofthelow‐proteindiets.Applegateetal.(2008)reportedsimilarlitternitrogeneffectswhenturkeytomswerefedreduced‐proteindiets.Noperformancedifferenceswereobserved.ThesedietswerethenfedtoturkeytomsbyLiuetal.(2011a),whoobserveda12percentreductioninNH3emissionsasaresultofreducingcumulativenitrogenintakeby9percent.FeedingspecificAAallowedforsimilarnitrogenintakesacrosstreatments,butreducedNH3emissionsby25percent(Liuetal.,2011a)andnitrogeninlitterby12percent(Liuetal.,2011b),becausenitrogenwasbetterutilizedbythebirds.Acrossalldiets,N2O


5-73

emissionsmadeuplessthanonepercentofnitrogenoutput(Liuetal.,2011b),suggestingthatreducingdietarynitrogenmayhavelessinfluenceonN2Oemissionsthanotherfactors.

FactorsAffectingEmissionsfromLayingHensDietfactorscanalterairemissionsfromlayinghenfacilities.MuchoftheworktodatehasfocusedonreducingNH3emissions.Robertsetal.(2007)showedthatinclusionofdietarycornDDGS,wheatmiddlings,orsoyhullsloweredtheseven‐daycumulativemanureNH3emissionfrom3.9gkgofdrymanure‐1forthecontrolto1.9,2.1,and2.3gkgofdrymanure‐1,respectively;italsoloweredthedailyNH3emissionrate.ReducingtheCPcontentbyonepercenthadnomeasurableeffectonNH3emission.Wu‐Haanetal.(2007b)fedareduced‐emissionsdietcontaining6.9percentofaCaSO4‐zeolitemixtureandslightlyreducedproteinto21‐,38‐,and59‐week‐oldHy‐LineW‐36hens;theyobservedthatdailyNH3emissionsfromhensfedthereduced‐emissionsdiets(185.5,312.2,and333.5mgbird‐1)werelessthanemissionsfromhensfedthecontroldiet(255.1,560.6,and616.3mgbird‐1)fortrials1,2,and3,respectively.Totalnitrogenexcretionfromhensfedthecontrolandreduced‐proteindietswasnotdifferent(Wu‐Haanetal.,2007a).Becauseoftheacidifyingnatureofthediets,themassofnitrogenremaininginexcretafollowingathree‐weekstorageperiodwaslessfromhensfedthecontroldietthanfromhensfedthereduced‐proteindiet(Wu‐Haanetal.,2007a).Lietal.(2010)foundthatfeedingcornDDGSdecreasedthemassofNH3emitteddailyby80mghen‐1(592vs.512mghen‐1day‐1forzeropercentand20percentDDGS,respectively),andby14percentpereggproduced,anddailyCH4emissionsby13to15percent(39.3vs.45.4mghen‐1day‐1;and0.70vs.0.82mggegg‐1day‐1).

5.3.8 LimitationsandUncertaintyinEntericFermentationandHousingEmissionsEstimates

Attheentitylevel,uncertaintyinentericCH4productionincattletypicallyresultsfrom,lackofprecisioninestimatingenergyintake,feedtypeandintake,characteristicsofparticularfeedstuffs(i.e.,aciddetergentfiber,starch,etc.),DE,maximumpossibleCH4emissions,CH4conversionfactors(Ym),synergiesorcountereffectsbetweenmitigationoptions,andnetenergyexpenditurebytheanimal.TheassumptionsaboutimplicationsofdietarychangesonentericCH4productionarebasedonliteraturevalues(includingempiricalfieldstudies)andmaynotbeindicativeoftruechangesinemissionsforparticularanimaltypes,asthiswillvarydependingonanindividualanimal’shealth,managementpractices,animalactivities,andbaselinediet.Forswine,goats,AmericanBison,llamas,alpacas,andmanagedwildlife,therecommendedestimationmethodsforemissionsfromentericfermentationarebasedontheIPCCTier1approach,whichhasanuncertaintyof30to50percent.

MethaneemissionsfromdairycattlehousingareasareestimatedusingequationsfromDairyGEM(IFSM).Inpredictingemissions,uncertaintywillresultfromalackofprecisioninestimatingexcretedvolatilesolidsandnitrogenexcreted,pH,temperature,airvelocity,andsurfaceareaofexposedmanure,beddingpack,CH4conversionfactors(MCFs),andmaximumCH4‐producingcapacityformanures.Comparisonofmodeledvalueswithon‐farmevaluationshasfoundthemodelpredictson‐farmemissionswithinfiveto20percent(unpublisheddata).

MethaneemissionsfrompoultryhousingareasareestimatedusingtheIPCCTier1method.Uncertaintyinpredictionsofemissionsresultfromalackofprecisioninestimatingfeedintake,nitrogenexcretedandvolatilesolids,MCF,volatilizationfraction,andinsomeinstancesemissionfactorsthatwerechoseninthemodel.UnfortunatelythereisalackofpublishedinformationrelatedtoGHGemissionsfrompoultryandtothebestofourknowledgethismodelhasnotbeenvalidated/testedusingon‐farmdata.


5-74

Muchofthepublisheduncertaintyinformationininventoryguidance,suchasIPCCGoodPracticeGuidance(IPCC,2000)andintheU.S.NationalGHGInventory(U.S.EPA,2013),focusonuncertaintiespresentincalculatinginventoriesattheregionalornationalscale,manyofwhichdonottranslatetotheentitylevel.Someofthesourcesofuncertaintyattheregionalornationalscaleincludedvariabilityinnativevegetationeatenbygrazinganimals,assumptionsaboutthetypesoffeedfarmersprovideforanimals(includingthepracticeofincludingnutritionalsupplements),managementpracticessuchashousingoptionsanddailyanimalactivity,averageanimalweights,andanimalpopulations.Thequantityofuncertaintyatlargerscalesisdifficulttodefine,dependentonboththeaccuracyinreportingpracticesandexperts’understandingoftheimplicationsofmanagementpracticesandtheaccuracyofparticularestimationmethodologies.Consistentimprovementinreportingpracticescanhelpremovesomeofthisuncertainty.

AvailabledefaultvaluesanduncertaintyinformationisincludedinTable5‐17.

Table5‐17:AvailableUncertaintyDataforEmissionsfromHousingandEntericFermentation

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue

Relativeuncertainty

Low(%)

Relativeuncertainty

High(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

DailyMilkProduction Milkkg

milk/animal/day

3% 5% ExpertAssessment

SupplementalFat(feedlot) S.Fat Percent 2 4 ExpertAssessment

Maximumdailyemissionsfordairycows Emax MJ/head 45.98 Millsetal.(2003)

TypicalAmmoniaLossesfromDairyHousingFacilities–Opendirtlots(cool,humidregion)

NH3loss

PercentofNex 15% 30%KoelshandStowell

(2005)TypicalAmmoniaLossesfromDairyHousingFacilities–Opendirtlots(hot,aridregion)

NH3loss


(2005)TypicalAmmoniaLossesfromDairyHousingFacilities–Roofedfacility(flushedorscraped)Roofedfacility(dailyscrapeandhaul)

NH3loss


(2005)

TypicalAmmoniaLossesfromDairyHousingFacilities–Roofedfacility(shallowpitunderfloor)

NH3loss


(2005)

TypicalAmmoniaLossesfromDairyHousingFacilities–Roofedfacility(beddedpack)

NH3loss


(2005)TypicalAmmoniaLossesfromDairyHousingFacilities–Roofedfacility(deeppitunderfloor,includesstorageloss)

NH3loss


(2005)

TypicalAmmoniaLossesfromBeefHousingFacilities–Opendirtlots(cool,humidregion)

NH3loss


(2005)

TypicalAmmoniaLossesfromBeefHousingFacilities–Opendirtlots(hot,aridregion)

NH3loss


(2005)

TypicalAmmoniaLossesfromBeefHousingFacilities–Roofedfacility(beddedpack)

NH3loss


(2005)

TypicalAmmoniaLossesfromBeefHousingFacilities–Roofedfacility(deeppitunderfloor,includesstorageloss)

NH3loss


(2005)

TypicalAmmoniaLossesfromSwineHousingFacilities–Roofedfacility(flushedorscraped)Roofedfacility(dailyscrapeandhaul)

%NH3loss


(2005)


5-75

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue

Relativeuncertainty

Low(%)

Relativeuncertainty

High(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

TypicalAmmoniaLossesfromSwineHousingFacilities–Roofedfacility(shallowpitunderfloor)

%NH3loss


(2005)

TypicalAmmoniaLossesfromSwineHousingFacilities–Roofedfacility(beddedpack)

%NH3loss


(2005)TypicalAmmoniaLossesfromSwineHousingFacilities–Roofedfacility(deeppitunderfloor,includesstorageloss)

%NH3loss


(2005)

TypicalAmmoniaLossesfromPoultryHousing–Roofedfacility(litter)(MeatProducingbirds)

%NH3loss


(2005)TypicalAmmoniaLossesfromPoultryHousing–Roofedfacility(stackedmanureunderfloor,includesstorageloss)(Egg‐producingbirds)

%NH3loss


(2005)

MethaneEmissionsfromGoats–Emissionfactorforgoats

EFGkg

CH4/head/day0.0137 IPCC(2006)

5.4 ManureManagement

Useofmanureasasourceofplantnutrientsreducestheneedforpurchasedcommercialfertilizer.Manurestorageallowsformanureapplicationstolandtobesynchronizedwithcropculturalneeds.Thispracticereducesthepotentialforsoilcompactionduetopoortimingofmanureapplication(wetsoilconditions)andmakesmoreefficientuseoffarmlabor.ManyanimalmanurestorageortreatmentstructurescreateanaerobicconditionsthatresultintheproductionandreleaseofGHGsandodors.Manurethatisrecycledtothelandbasecanhavepotentialnegativeeffectsonwaterquality(bothsurfaceandgroundwater).

Manurestorageandtreatment,asacomponentofmanuremanagementsystems,playsacriticalroleinGHGemissions.Attheentitylevel,variousmanurestorageandtreatmentapproacheswillleadtodifferentamountsofGHGemission.Animalmanurecanbeclassifiedintotwocategoriesbasedontheirphysicalproperties:solid,definedasdrymatterabove15percent;andliquid,definedasdrymatteroflessthan15percent(includingliquidmanurewithadrymatteroflessthan10percentandslurrymanurewithadrymatterbetween10and15percent).Threesolidmanurestorage/treatmentpractices(temporarystack/long‐termstockpile,composting,andthermo‐chemicalconversion)andeightliquidmanurestorage/treatmentpractices(aerobiclagoon,anaerobiclagoon/runoffholdingpond/storagetanks,anaerobicdigestion,combinedaerobictreatmentsystem,sand‐manureseparation,nutrientremoval,solid‐liquidseparation,andconstructedwetland)wereevaluatedandtheemissionestimationmethodsarepresented.Atthefarmentitylevel,severalpracticesareoftenstrategicallycombinedtotreatmanure.Inordertoprovidetoolstoevaluatethesescenarios,activitydata(i.e.,massflowdataandchemicalandphysicalcharacteristicsofinfluentandeffluent,environmentaltemperature,pH,andtotalnitrogen)fromindividualpracticeswillbeusedtolinkpracticesinthecombinedsystemforindividualfarmentities.AschematicstructureofpossiblecombinationsofmanurestorageandtreatmentpracticesattheentitylevelispresentedinFigure5‐7.Asillustratedinthefigure,manurecanbehandledasasolidorliquid.Foreachstream,themanurecanbeapplieddirectlytoland,stored,ortreatedbeforestorageorlandapplication.Insomepractices,solidsareseparatedfromtheliquidmanurestreamandtreatedusingasolidshandlingsystem.


5-76

Figure5‐7:SchematicStructureofPossibleCombinationofManureStorageandTreatmentPractices

Note:Individualpracticescouldbecombinedtogethertotreatmanurebasedontheneedattheentitylevel.

Eachmanuremanagementpracticeisdescribedasanindividualunitpracticeinthisdocument.ThereferencesforestimationofGHGemissionforindividualpracticearelistedinTable5‐18.

Table5‐18:ListofIndividualManureStorageandTreatmentPractices

Section StorageandTreatmentPracticesMajorReferencesforGHG

EstimationSolidmanure5.4.1 Temporaryandlong‐termstorage IPCC(2006);U.S.EPA(2011)0 Composting IPCC(2006);U.S.EPA(2011)Liquidmanure5.4.3 Aerobiclagoon IPCC(2006);U.S.EPA(2011)

5.4.4Anaerobiclagoon/runoffholdingponds/storagetanks

Sommeretal.(2004)

5.4.5 Anaerobicdigestionwithbiogasutilization IPCC(2006);CDM(2012)


5-77

Section StorageandTreatmentPracticesMajorReferencesforGHG

Estimation5.4.6 Combinedaerobictreatmentsystem Vanottietal.(2008)5.4.7 Sand–manureseparation5.4.8 Nutrientremoval5.4.9 Solid–liquidseparation FordandFleming(2002)

5.4.10 ConstructedwetlandSteinetal.(2006;2007b)Stoneetal.(2002;2004)

5.4.11 Thermo‐chemicalconversion

TheremainderofthissectionpresentsthemethodforestimatingGHGsfromthesourceslistedinTable5‐18.ForeachsourceofGHGswithanestimationmethod,thefollowinginformationisprovided:

OverviewoftheGHGSourceandtheResultingGHGs.Thissectionprovidesanoverviewofmanuremanagementtechnology,theresultingGHGemissions,andthemethodologyproposedforestimatingtheemissions.

RationaleforSelectedMethod.Thissectionpresentsthereasoningfortheselectionofthemethodrecommendedinthisreport.

ActivityData.ThissectionliststheactivitydatarequiredforestimatingGHGsattheentitylevel.

AncillaryData.ThissectionlistsancillarydatasuchasCH4conversionfactors(MCF)andmaximumCH4productioncapacity(B0).

Method.Thissectionprovidesdetaileddescriptions,includingequationsfortheselectedmethods.

ForeachsourceofGHGswithoutanestimationmethod,aqualitativeoverviewisprovided.MethodsforestimatingNH3emissionsareprovidedinAppendix5‐C.

5.4.1 TemporaryStackandLong‐TermStockpile

5.4.1.1 OverviewofTemporaryStackandLong‐TermStockpiles

Managementmethodsforstoredmanurearedifferentiatedbythelengthoftimetheyarestockpiled(i.e.,temporarystackandlong‐termstorage).Temporarystackisashort‐termmanurestoragemethodthatisusedtotemporarilyholdsolidmanurewhenbadweatherprohibitslandapplication,and/orwhenthereislimitedavailabilityofcroplandformanureapplication.Withtemporarystack,

MethodforEstimatingEmissionsfromManureStorageandTreatment–TemporaryStackandLong‐TermStockpile

Methane

IPCCTier2approachusingIPCCandU.S.EPAInventoryemissionfactors,utilizingmonthlydataonvolatilesolidsanddrymanure.Volatilesolidscontentcanbeobtainedfromsamplingandlabtesting.

Methodisonlyreadilyavailablemethod.

NitrousOxide

IPCCTier2approachusingU.S.‐basedemissionfactorsandmonthlydataonvolatilesolids,totalnitrogen,anddrymanure.

Nospecificmodelsexist;methodistheonlyreadilyavailablemethod.


5-78

themanureisremovedandappliedtolandwithinafewweeksofpiling.Temporarystorageisnotapreferredmethodtostoremanurebecauseitrequiresthemanuretobehandledtwice.

Long‐termstorageisapermanentmanurestoragemethodinwhichsolidmanureispiledonaconfinedareaorstoredinadeeppitforlongerthansixmonths.Inlow‐rainfallareas,thestockpilecanbepiledonthefieldwiththeinstallationofnutrientrunoffcontrol.Inhigherrainfallareas,aconcretepadandwallareconstructedtostoresolidmanureandpreventnutrientrunofffromheavyrain.

Greenhousegasesgeneratedfrombothstoragemethodshaveapatternsimilartothatofentericfermentation.CarbonandnitrogencompoundsinmanurearebrokendownbymicrobestoCH4,andN2O.ThemainfactorsinfluencingGHGemissionsfromstoragearetemperatureandstoragetime.Duetothelongerstoragetime,long‐termstockpilesolidmanurestoragegeneratesasignificantamountofGHGs.Temporarystack,asashort‐termmanurestoragemethod,generateslessGHGsthanthelong‐termstockpilesolidstorage.However,itisstillnecessarytoquantitativelydelineatetheemissionsinordertoassistlivestockandpoultryfarmsinevaluatingtheirmanuremanagementoperations.Temporarystackandlong‐termstockpilesofmanurealsoproduceNH3;proposedmethodstoestimateNH3emissionsarepresentedinAppendix5‐C.

TheIPCCTier2methodologyisprovidedforestimatingCH4emissionsfromtemporarystacksorlong‐termstockpiles.ThismethodologyusesacombinationofIPCCandcountry‐specificemissionfactorsfromtheU.S.EPAGHGInventory.Theamountofmanure,volatilesolidscontent,andtemperaturearespecifictotheentity.ThemethodforcalculatingN2OemissionsisthesameastheequationpresentedintheU.S.GHGInventory.

RationaleforSelectedMethodTheIPCCequationsaretheonlyavailablemethodsforestimatingCH4,andN2Oemissionsfromtemporarystackandlong‐termstockpiles.Thesemethodologiesbestdescribethequantitativerelationshipamongactivitydataattheentitylevel.

ActivityDataInordertoestimatethedailyCH4emissions,thefollowinginformationisneeded:9

Animaltype Totaldrymanure Volatilesolidsofdrymanure10 Temperatures(localambienttemperatureandmanuretemperature)

InordertoestimatethedailyN2Oemission,thefollowinginformationisneeded:

Totaldrymanure Totalnitrogencontentofthemanure

ThetotalnitrogencontentofthemanureenteringstoragesystemscanbeestimatedaccordingtothenitrogenbalancemethodasdescribedinEquation5‐9:TotalNitrogenEnteringManureStorageandTreatmentThefractionofnitrogenexcretedbyananimalthatisnotemittedasagasistheportionthatentersstorage.

9Althoughdailyestimatesfortheactivitydataareoptimal,trackingthislevelofdetailwouldbeburdensome.Annualestimatesdon’tallowforseasonalvariationindietsandclimate.Consequently,disaggregationofthedatabyseasonorbyperiodsofmajorshiftsinanimalpopulationissuggested.

10Volatilesolids,totalnitrogencontent,andammonia‐nitrogencontentshouldbeobtainedthroughsamplingandlabtesting.


5-79

AncillaryDataTheancillarydatausedtoestimateCH4emissionfortemporarystorageandlongtermstockpilesare:maximumCH4producingcapacities(B0)andMCFs.TheB0valuesforsolidmanurestorageareobtainedfromtheIPCCandlistedinTable5‐19.Methaneconversionfactorsfordifferentmanuremanagementsystems(includingtemporarystorageofsolidmanure)arealsoobtainedfromtheIPCCandlistedinTable5‐20and5‐16.

TheancillarydatausedtoestimateN2OemissionsfortemporarystorageandlongtermstockpilesaretheN2OemissionfactorsforsolidmanurestoragesystemsarepresentedinTable5‐23(U.S.EPA,2011).

5.4.1.2 Method

MethaneEmissionsfromTemporaryStackandLong‐TermStockpileTheTier2approachbytheIPCCmodelisrecommendedtoestimateCH4emissionsandisdescribedinEquation5‐26(IPCC,2006).DailyCH4emissionisestimatedasafunctionofthevolatilesolidsinmanureplacedintothestorageandtheanimal‐specificMCF.

aDrymanurereferstomaterialremainingafterremovalofwater.Itisdeterminedthroughtheevaporationofwaterfromthemanuresampleat103‐105°C.Forcedairovenisthemostcommonequipmenttomeasurethedrymatter.

Table5‐19:MaximumCH4ProducingCapacities(B0)fromDifferentAnimals

Animal

MaximumCH4

ProducingCapacity(B0)

(m3/kgVS)

Animal

MaximumCH4

ProducingCapacity(B0)

(m3/kgVS)Beefreplacementheifers 0.33b Breedingswine 0.48Dairyreplacementheifers 0.17b Layer(dry) 0.39Maturebeefcows 0.33b Layer(wet) 0.39Steers(>500lbs) 0.33b Broiler 0.36Stockers(All) 0.17b Turkey 0.36Cattleonfeed 0.33b Duck 0.36Dairycow 0.24b Sheep 0.19bCattle 0.19b Feedlotsheep 0.36bBuffalo 0.1a Goat 0.17b

Marketswine 0.48Horse 0.3Mule/Ass 0.33

aTherearenodataforNorthAmericaregion;thedatafromWesternEuropeareusedtocalculatetheestimation.bNumbersarefromtheEPAU.S.Inventory:1990‐2009(U.S.EPA,2011).OthernumbersarefromIPCC(2006).

Equation5‐26:IPCCTier2ApproachforEstimatingCH4 Emissions

.

Where:ECH4 =CH4emissionsperday(kgCH4day‐1)m =Totaldrymanureperdaya(kgdrymanureday‐1)VS =Volatilesolids(kgVS(kgdrymanure)‐1)B0 =MaximumCH4producingcapacityformanure(m3CH4(kgVS)‐1)MCF =CH4conversionfactorforthemanuremanagementsystem(%)0.67=Conversionfactorofm3CH4 tokgCH4


5-80

Table5‐20:MethaneConversionFactorsforTemporaryStorageofSolidManurefromDifferentAnimals

AnimalMethaneConversionFactor(%)

Temp=10‐14°C Temp=15‐25°C Temp=26‐28°CDairycow 1 1.5 2Cattle 1 1.5 2Buffalo 1 1.5 2Marketswine 1 1.5 2Breedingswine 1 1.5 2Layer(dry) 1.5 1.5 1.5Broiler 1.5 1.5 1.5Turkey 1.5 1.5 1.5Duck 1 1.5 2Sheep 1 1.5 2Goat 1 1.5 2Horse 1 1.5 2Mule/Ass 1 1.5 2

Source:IPCC(2006).

Table5‐21:MethaneConversionFactorsforLong‐TermStockStorageofSolidManurefromDifferentAnimals


Temp= 10‐14°C Temp=15‐25°C Temp=26‐28°CDairycow 2 4 5Cattle 2 4 5Buffalo 2 4 5Marketswine 2 4 5Breedingswine 2 4 5Layer(dry) 1.5 1.5 1.5Broiler 1.5 1.5 1.5Turkey 1.5 1.5 1.5Duck 1 1.5 2Sheep 1 1.5 2Goat 1 1.5 2Horse 1 1.5 2Mule/Ass 1 1.5 2

Source:IPCC(2006).

Table5‐22:MethaneConversionFactorsforLong‐TermStorageofSlurryManurefromBuffalo

Temperature(°C)Methane Conversion

Factor(%)Temperature(°C)

MethaneConversionFactor(%)

10 17 20 4211 19 21 4612 20 22 5013 22 23 5514 25 24 6015 27 25 6516 29 26 7117 32 27 7818 35 28 8019 39

Source:IPCC(2006).


5-81

NitrousOxideEmissionsfromTemporaryStackandLong‐TermStockpileNitrousoxideemissionsaredependentonnitrificationanddenitrification.ManurestorageisoneofthemainsourcesofU.S.overallN2Oemissions.TheonlyquantitativemethodforestimatingN2OemissionsfromsolidmanureistheIPCCTier2approach,whichisalsousedfortheU.S.Inventory.ThisapproachisbasedontheuseofemissionfactorsfromthemostrecentIPCCGuidelinesandtotalnitrogenvaluesareestimatedaccordingtoEquation5‐9.Equation5‐27presentstheequationtoestimatetheN2Oemissionsforsolidmanure.


Table5‐23:N2OEmissionFactorsforSolidManureStorageTypeofStorage N2OEmissionFactor(kgN2O‐N/kgN)

Temporarystorageofsolid/slurrymanure 0.005

Long‐termstorageofsolidmanure 0.002

Long‐termstorageofslurrymanure 0.005Source:U.S.EPA(2011).

5.4.2 Composting

5.4.2.1 OverviewofComposting

Equation5‐27:IPCCTier2ApproachforEstimatingN2OEmissions

Where:

EN2O =Nitrousoxideemissionperday(kgN2Oday‐1)

m =Totaldrymanureperdaya(kgdrymanureday‐1)

EFN2O=N2Oemissionfactor(kgN2O‐NkgN‐1)

TN =Totalnitrogenatagivenday(kgN(kgdrymanure)‐1)


MethodforEstimatingEmissionsfromManureStorageandTreatment–Composting

Methane

IPCCTier2approach,utilizingmonthlydataonvolatilesolidsanddrymanure.Volatilesolidscontentcanbeobtainedfromsamplingandlabtesting.

Methodistheonlyreadilyavailablemethod.

NitrousOxide

IPCCTier2approach,utilizingdataonanitrousoxideemissionfactor,totalinitialnitrogen,anddrymanure.

Methoddependsonwhetherthesystemisinvessel,staticpile,intensivewindrow,orpassivewindrow.

Methodisonlyreadilyavailablemethod.


5-82

Compostingisthecontrolledaerobicdecompositionoforganicmaterialintoastable,humus‐likeproduct(USDANRCS,2007).Animalmanuremaybecompostedinavarietyofdifferentsystems,includingin‐vesselsystems,windrows,orstaticpiles.In‐vesselsystemshandlecompostinaclosedsystemsuchasarotarydrumorboxthatincorporatesregularmovementtoensureproperaeration.Thelargestcompostingoperationsdivideupthecompostintolongheapsforwindrowcompostingorintoonelargepileforaeratedstaticpilecomposting.Intheformermethod,properoxygenflowcanbemaintainedviamanualturningorpipesystems,whereasinthelattermethod,itismaintainedthroughpipesystems.Compostinghasbecomeapopularmethodinsomeregionstodecreasethevolumeandweightoflivestockmanureandtoproduceaproductthatisoftenmoreacceptabletofarmersasafertilizer.Duringa100‐to120‐daycompostingperiod,theweightandvolumeofmanuremaybedecreasedby15to70percent(Eghballetal.,1997;Inbaretal.,1993;Lopez‐Real&Baptista,1996).Furthermore,theheatgeneratedthroughthecompostingprocesscankillparasites,pathogens,andweedseedsfoundinanimalwaste,creatingasaferproductforcropapplication.

ThequantityofGHGemissionsisaffectedbythecompostingmethodemployed.Haoetal.(2001)reportedthatGHGemissionsfromcattlemanurecompostincreasedabouttwofoldwhenthecompostwasactivelycompostedratherthanpassivelycompostedinwindrows.Activewindrowswereturnedsixtimes(days14,21,29,50,70,and84).Passivewindrowswereneverturned,butairwasintroducedintothewindrowsbyaseriesofopen‐endedperforatedsteelpipes.TotheextentthattherateofGHGformationdependsonoxygensaturationintheporespace,aerationmethod(i.e.,forced‐airvs.passive/convective)andrate(orturningfrequency)willaffectthemagnitudeofGHGemissionsduringthecompostingprocess.

Eghballetal.(1997)reportedthat19to45percentofthenitrogenpresentinmanurewaslostduringcomposting,withthemajorityofthispresumablyasNH3.Usingchangesinthenitrogen:phosphorusratiooffeedlotmanurethatwasplacedincompostwindrowsandthenitrogen:phosphorusratioof“finished”compost,Coleetal.(2011)estimatedthat10to20percentofnitrogenwaslostduringcomposting.TheU.S.EPAcurrentlyassumesthatoneto10percentofnitrogenenteringcompostsystemsislostasN2O(IPCC,2006;U.S.EPA,2009).

TheIPCCTier2methodologyisprovidedforestimatingCH4andN2Oemissionsfromcomposting.Thismethodologyusescountry‐specificemissionfactorsfromtheU.S.EPAGHGInventory.Theamountofmanure,volatilesolidscontent,andtemperaturearespecifictotheentity.TheGHGestimationmethodformanurecompostingdoesnotconsiderotherorganiccarbonsourcesthatmightbeaddedintomanurecomposting.

RationaleforSelectedMethodTheIPCCequationsaretheonlyavailablemethodsforestimatingCH4andN2Oemissionsfromcomposting.Thesemethodologiesbestdescribethequantitativerelationshipamongstactivitydataattheentitylevel.

5.4.2.2 ActivityData

InordertoestimatethedailyCH4emissions,thefollowinginformationisneeded:

Animaltype Totaldrymanure Volatilesolidsofdrymanure Temperatures(localambienttemperatureandmanuretemperature)

InordertoestimatethedailyN2Oemissions,thefollowinginformationisneeded:

Totaldrymanureinthestorage


5-83

Totalnitrogeninmanure

ThetotalnitrogencontentofthemanureenteringstoragesystemscanbeestimatedaccordingtothenitrogenbalancemethodasdescribedinEquation5‐9:TotalNitrogenEnteringManureStorageandTreatmentThefractionofnitrogenexcretedbyananimalthatisnotemittedasagasistheportionthatentersstorage.

5.4.2.3 AncillaryData

TheancillarydatausedtoestimateCH4emissionsformanurecompostingare:maximumCH4producingcapacities(B0)andMCFs.TheB0valuesareobtainedfromtheIPCC(2006)andlistedinTable5‐19.TheMCFvaluesareobtainedfromEPA(U.S.EPA,2011)andlistedinTable5‐24.

TheancillarydatausedtoestimateN2OemissionformanurecompostingaretheN2Oemissionfactors(Table5‐25).

5.4.2.4 Method

MethaneEmissionsfromCompostingTheTier2approachintheIPCCmodelisadaptedwithcountry‐specificfactorstoestimateCH4emissionsfromcompostingofsolidmanure.DailyCH4emissionsareestimatedasafunctionofthevolatilesolidsinmanureplacedintothestorageandtheMCF.


TheB0valuesforcompostingsolidmanureareobtainedfromtheIPCC(2006)andarelistedinTable5‐19.MethaneconversionfactorsfordifferentapproachesofcompostingsolidmanureareobtainedfromIPCC(2006).

Equation5‐28:IPCCTier2ApproachforCalculatingMethaneEmissionsfromCompostingSolidManure

.

Where:

ECH4 =Methaneemissionsperday(kgCH4day‐1)

m =Totaldrymanurea(kgdrymanureday‐1)


B0 =MaximumCH4producingcapacityformanure(m3CH4(kgVS)‐1)(seeTable5‐24)

MCF =Methaneconversionfactorforthemanuremanagementsystem(%)

0.67 =Conversionfactorofm3CH4tokgCH4


5-84

Table5‐24:MethaneConversionFactorsforCompostingSolidManure


CoolClimate TemperateClimate

WarmClimate

Manurecomposting–invessel 0.5 0.5 0.5

Manurecomposting–staticpile 0.5 0.5 0.5Manurecomposting–intensivewindrow

0.5 1 1.5

Manurecomposting–passivewindrow 0.5 1 1.5Source:IPCC(2006).

NitrousOxideEmissionsfromCompostingATier2IPCCmodelisadaptedtoestimateN2Oemissionsfromcompostingofsolidmanure.Equation5‐29presentstheequationforestimatingN2Oemissionsfromcompostingofsolidmanure.EmissionfactorsfordifferentcompostingmethodsarelistedinTable5‐25andtotalnitrogenisestimatedaccordingtoEquation5‐9.11


Table5‐25:N2OConversionFactors(EFN2O)forCompostingSolidManure

Category N2OEmissionFactor(kgN2O‐N/kgTN)CattleandSwineDeepBedding(ActiveMix) 0.07

CattleandSwineDeepBedding(NoMix) 0.01

PitStorageBelowAnimalConfinements 0.002Source:IPCC(2006).

11SomestudieshavebeenconductedontherateofN2Oemissionsforswine(Fukummotoetal.,2003;Szantoetal.,2006)butthisdataislimitedandfurtherresearchisnecessary.SeeSection0ResearchGapsforfurtherdiscussion.

Equation5‐29:IPCCTier2ApproachforEstimatingN2OEmissionsfromCompostingofSolidManure

Where:

EN2O =Nitrousoxideemissionsperday(kgN2Oday‐1)

m =Totaldrymanurea(kgday‐1)

EFN2O=N2Oemission(loss)relativetototalnitrogeninmanure(kgN2O‐N(kgTN)‐1)

TN =Totalnitrogenintheinitial(fresh)manure(kgTN(kgdrymanure)‐1)



5-85

5.4.3 AerobicLagoon

5.4.3.1 OverviewofAerobicLagoons

Aerobiclagoonsareman‐madeoutdoorbasinsthatholdanimalwastes.Theaerobictreatmentofmanureinvolvesthebiologicaloxidationofmanureasaliquid,witheitherforcedornaturalaeration.Naturalaerationislimitedtoaerobiclagoonswithphotosynthesisandisconsequentlyshallowtoallowforoxygentransferandlightpenetration.Thesesystemsbecomeanoxicduringlow‐sunlightperiods.Duetothedepthlimitation,naturallyaeratedaerobiclagoonshavelargesurfacearearequirementsandareimpracticalforlargeoperations.

TheIPCCTier2methodologyisprovidedforestimatingCH4andN2Oemissionsfromaerobiclagoons.ThismethodologyusesacombinationofIPCCandcountry‐specificemissionfactorsfromtheU.S.EPAGHGInventory.AerobicconditionsresultintheoxidationofcarbontoCO2,notthereductionofcarbontoCH4,thusCH4emissionsfromaerobiclagoonsisconsiderednegligibleandisdesignatedaszeroinaccordancewithIPCC.ThemethodforcalculatingN2Oemissionsaccountsforthevolumeofthelagoonaswellasthetotalnitrogencontentofthemanure.

5.4.3.2 RationaleforSelectedMethods

TheIPCCequationsaretheonlyavailablemethodsforestimatingCH4,andN2Oemissionsfromaerobiclagoons.Thesemethodologiesbestdescribethequantitativerelationshipamongactivitydataattheentitylevel.


Noactivitydataareneeded(MCF=0)fortheestimationofCH4gasemissions.

InordertoestimatethedailyN2Oemissions,thefollowinginformationisneeded:

Surfaceareaoflagoon Volumeofthematerialinthelagoon Totalnitrogencontentofthemanure

ThetotalnitrogencontentofthemanureenteringstoragesystemscanbeestimatedaccordingtothenitrogenbalancemethodasdescribedinEquation5‐9.Thefractionofnitrogenexcretedbyananimalthatisnotemittedasagasistheportionthatentersstorage.


TheancillarydatausedtoestimateN2OemissionsforaerobiclagoonareN2Oemissionfactors(U.S.EPA,2011).

MethodforEstimatingEmissionsfromManureStorageandTreatment–AerobicLagoon

Methane

TheMCFforaerobictreatmentisnegligibleandisdesignatedaszeropercentinaccordancewiththeIPCCGuidance.

NitrousOxide

IPCCTier2methodutilizingIPCCemissionfactors. Methodtakesintoaccountthevolumeofthelagoonandthetotalnitrogencontentof

themanure. Methodistheonlyreadilyavailablemethod.


5-86

5.4.3.5 Method

MethaneEmissionsfromAerobicLagoonTheMCFforaerobictreatmentisnegligibleandwasdesignatedaszeropercentinaccordancewiththeIPCC(2006).ThesolidsfromthebottomofthelagoonhavesignificantvolatilesolidsandB0associatedwithlivestocktype;thecharacteristicsofthesolidsshouldbemeasuredandusedastheinputstoestimateemissionsofGHGsforsubsequentstorageandtreatmentoperations.

NitrousOxideEmissionsfromAerobicLagoonTheTier2approachintheIPCCmodelisadaptedtoestimateN2Oemissionsfromaerobiclagoons.TheN2OconversionfactorsfordifferentaerationsystemarelistedinTable5‐26.TheestimationmethodforN2OemissionsisprovidedinEquation5‐30.

5.4.4 AnaerobicLagoon,RunoffHoldingPond,StorageTanks

5.4.4.1 OverviewofAnaerobicLagoons,RunoffHoldingPonds,andStorageTanks

Table5‐26:N2OConversionFactors(EFN2O)forAerobicLagoons

AerationTypeN2OConversion Factor

(kgN2O‐N/kgN)Naturalaeration 0.01Forcedaeration 0.005Source:IPCC(2006).

Equation5‐30:CalculatingN2OemissionsfromAerobicLagoons

Where:


V =Totalvolumeofthelagoonliquid(m3day‐1)

EFN2O=Nitrousoxideemission(loss)relativetototalnitrogeninthelagoonliquid (kgN2O‐N(kgTN)‐1)

TN =Totalnitrogeninthelagoonliquid(kgTNm‐3)


MethodforEstimatingEmissionsfromManureStorageandTreatment–AnaerobicLagoons,RunoffHoldingPonds,StorageTanks

Methane

Sommermodel(Sommeretal.,2004)isusedwithdegradableandnondegradablefractionsofvolatilesolidsfromMølleretal.(2004).

Thismethodwasselectedasitaccountsformanuretemperatureandtotalvolatilesolidscontentofmanure.Volatilesolidscontentcanbeobtainedfromsamplingandlabtesting.

NitrousOxide

EmissionsareafunctionoftheexposedsurfaceareaandU.S.‐basedemissionfactors. Methodistheonlyreadilyavailableoption.


5-87

Themostfrequentlyusedliquidmanurestoragesystemsareanaerobiclagoons(intheSouthernportionoftheUnitedStates),earthenorearthen‐linedstorages(intheNorthernportionofthecountry),runoffholdingponds,andabove‐gradestoragetanks.Anaerobiclagoonsareearthenbasinsthatprovideanenvironmentforanaerobicdigestionandstorageofanimalwaste.BoththeAmericanSocietyofAgriculturalandBiologicalEngineersandU.S.DepartmentofAgricultureNaturalResourcesConservationServicehaveengineeringdesignstandardsforconstructionandoperationofanaerobiclagoons.Inmostfeedlotsaholdingpondisconstructedtocollectrunoffforshort‐termstorage.Storagetanksrangefromlower‐costearthenbasinstohigher‐cost,glass‐linedsteeltanks.Themanurethatentersthesesystemsisusuallydilutedwithflushwater,waterwastedatstalls,andrainwater.

Allofthesestoragesystems(withoutaeration)arebiologically‐anaerobiclagoons,whichmeanthattheyhavesimilarpotential,aswithentericfermentation,toproduceCH4andN2O.DuetothelargequantityofliquidmanureproducedintheUnitedStates,liquidmanurestoragecanbeamajorsourceofGHGemissionsfromanimaloperations.IntermsofestimationofGHGemissionfromanaerobiclagoon/runoffholdingpond/storagetanks,thesestoragesystemsareclassifiedintofourcategories:1)coveredstoragewithacrustformedonthesurface;2)coveredstoragewithoutacrustformedonthesurface;3)uncoveredstoragewithacrustformedonthesurface;and4)uncoveredstoragewithoutacrustformedonthesurface.

ThealgorithmsforcalculatingCH4emissionsdescribedbySommeretal.(2004)arerecommendedforestimatingemissionsattheentity‐level.Themodelconsidersvolatilesolidstobethemainfactorinfluencingemissionsfrommanureandrelatesemissionstothecontentofdegradablevolatilesolids.Nitrousoxideisestimatedasafunctionoftheexposedsurfaceareaofthemanurestorageandwhetheracrustispresentonthesurface.

RationaleforSelectedMethodsTheSommeralgorithmslinkcarbonturnover,volatilesolids,temperature,andstoragetimetoCH4emissionsestimatesandisthebestavailablemethodforestimatingCH4emissionsattheentitylevel.ThemethodprovidedforN2Oistheonlyavailablemethodforestimatingemissions.Thesemethodologiesbestdescribethequantitativerelationshipamongactivitydataattheentitylevel.


InordertoestimatethedailyCH4emissions,thefollowinginformationisneeded:

Animaltype Totaldrymanure Volatilesolidsinthestorage Temperatures(localambienttemperatureandmanuretemperature)

InordertoestimatetheN2Oemission,thefollowinginformationisneeded:

Totaldrymanure Totalnitrogencontentofthemanure Theexposedsurfaceareaofthemanurestorage

ThetotalnitrogencontentofthemanureenteringstoragesystemscanbeestimatedaccordingtothenitrogenbalancemethodasdescribedinEquation5‐9.Thefractionofnitrogenexcretedbyananimalthatisnotemittedasagasistheportionthatentersstorage.


TheancillarydatausedtoestimateCH4emissionsforanaerobiclagoons,runoffholdingponds,andstoragetanksarethemaximumCH4producingcapacities(B0),potentialCH4yield(ECH4,pot),rate


5-88

correctingfactors(b1andb2),Arrheniusconstant(A),activationenergy(E),gasconstant(r),andcollectionefficiency(η)forliquidmanurestoragefromdifferentanimals.ThesedataareavailablefromtheIPCC(2006)andSommeretal.(2004)andarelistedinTable5‐27.

TheancillarydatausedtoestimateN2Oemissionsforanaerobiclagoons,runoffholdingponds,andstoragetanksistheN2OemissionfactorfromTable5‐29(U.S.EPA,2011).

5.4.4.4 Method

MethaneEmissionsfromAnaerobicLagoons,RunoffHoldingPonds,StorageTanksTheSommermodel(Sommeretal.,2004)isusedastheestimationmethodforCH4emission(Rotzetal.,2011b).DailyCH4emissionsareestimatedasafunctionofmanuretemperatureandthevolatilesolidsinmanureplacedintoliquidstorages.TheparametersfortheestimationarelistedinTable5‐28.


ThedegradablefractionofthevolatilesolidsisdependentonthepotentialCH4yieldandthemaximumCH4producingcapacitiesandcanbecalculatedusingEquation5‐32.Thefractionofnondegradablevolatilesolids(materialthatisnotbrokendownbymicroorganisms)iscalculatedfromthetotalvolatilesolidscontentanddegradablefractionofthevolatilesolids,asdescribedbyEquation5‐33.TheB0valuesareobtainedfromtheIPCC(2006)andarelistedinTable5‐19.

Equation5‐31:UsingtheSommerModeltoCalculateDailyCH4Emissions

.

Where:

ECH4 =Methaneemissionperday(kgCH4day‐1)

m =Totaldrymanureperday(kgdrymanureday‐1)a

0.024 =DimensionlessfactortomodifytheSommermodelbasedonVS

VSdandVSnd =DegradableandnondegradableVSinthemanure,respectively (kg(kgdrymanure)‐1)

b1andb2 =Ratecorrectingfactors(dimensionless)

A =Arrheniusparameter(gCH4(kgVS)‐1hr‐1)

E =Activationenergy(Jmol‐1)

R =Gasconstant(JK‐1mol‐1)

T =Storagetemperature(K)

η =Collectionefficiencyofdifferentliquidstoragecategories


5-89

Thecollectionefficiency(η)dependsondifferentliquidstoragecategoriesof:1)coveredstoragewithacrustformedonthesurface;2)coveredstoragewithoutacrustformedonthesurface;3)uncoveredstoragewithacrustformedonthesurface;and4)uncoveredstoragewithoutacrustformedonthesurface.AcrustallowsairandCH4toberetainedonthesurfaceofthemanurestorageandincreasesthepotentialforoxidationofCH4(Hansenetal.,2009;Nielsenetal.,2010).Whenacrustdoesnotform,CH4isdirectlyemittedwithoutrapidoxidation.Forcattleslurryandpigslurry,degradableandnondegradablevolatilesolids(asafractionofVST)aregiveninTable5‐28.

Table5‐27:ParametersforEstimatingCH4EmissionfromLiquidManureStorage

Parameters Cattle Swine

Arrheniusconstant(ln(A))–gCH4(kgVS)‐1hr‐1 43.33 43.21

Activationenergy(E)–Jmol‐1 1.127×105 1.127×105

Gasconstant(R)–JK‐1mol‐1 8.314 8.314

RatecorrectionfactorforVSd(b1) 1 1

RatecorrectionfactorforVSnd(b2) 0.01 0.01

Potentialmethaneyieldofthemanure(ECH4,pot)(kgCH4/kgVS) 0.48 0.50

Collectionefficiency(η)

Coveredstoragewithacrustformonthesurfacea 1 1

Coveredstoragewithoutacrustformonthesurfacea 1 1

Uncoveredstoragewithacrustformonthesurfaceb 0 0

Uncoveredstoragewithoutacrustformonthesurfacec ‐0.4 ‐0.4Source:Sommeretal.(2004)andIPCC(2006).aCH4gasfromcoveredstoragewithacrustformonthesurfaceiscollectedandflared.bUncoveredstoragewithacrustformonthesurfaceisusedforthederivationofEquation5‐22.cTheemissionforuncoveredstoragewithoutacrustis40percentgreaterthanuncoveredstoragewithacrust,sothecollectionefficiencyforthiscaseis‐40percent.

Equation5‐32:CalculatingtheDegradableFractionoftheVolatileSolids

,

Where:

VSd =DegradableVSfractionsinthemanureonagivenday(kg(kgdrymanure)‐1)

VST =Volatilesolidscontentinthestorageonagivenday(kg(kgdrymanure)‐1)

B0 =MaximumCH4producingcapacities(kgCH4(kgVS)‐1)

ECH4,pot =PotentialCH4yieldofthemanure(kgCH4(kgVS)‐1)

Equation5‐33:CalculatingtheNon‐DegradableFractionoftheVolatileSolids

Where:

VSdandVSnd =DegradableandnondegradableVSfractionsinthemanureonagivenday (kg(kgdrymanure)‐1),respectively

VST =Volatilesolidscontentinthestorageonagivenday (kg(kgdrymanure)‐1)


5-90

Table5‐28:DegradableandNondegradableVolatileSolidsforCattleandSwineManure

TypeofManure VSd/VST VSnd/VST

Cattleliquidmanure 0.46 0.54

Swineliquidmanure 0.89 0.11Source:Mølleretal.(2004).

NitrousOxideEmissionsfromAnaerobicLagoon,RunoffHoldingPond,StorageTanksNitrousoxideemissionsfromliquidmanurestoragetypicallyrepresentarelativelysmallportionoftheN2Oemissionsfromfarms.MoststudiesindicatethecriticalityofthecrustfortheformationandemissionofN2O(PetersenandSommer,2011).Therefore,N2Oemissionsfromliquidmanurestorageareestimatedasafunctionoftheexposedsurfaceareaofthemanurestorageandthepresenceofacrustonthesurface.

TheemissionfactorofN2Oisdependentoncrustformationontheliquidstorage.Thecrustallowsairtoberetainedonthesurfaceofthemanurestorageandincreasesthepotentialfornitrificationanddenitrification(Hansenetal.,2009;Nielsenetal.,2010).Whenacrustdoesnotform,oxygenisnotretainedontheliquidsurfacewithnitrogenouscompounds,andthereforenoN2Oisformedandemitted.TheemissionfactorsofN2OfordifferentliquidstoragemethodsarelistedinTable5‐29.

Table5‐29:EmissionFactorofN2OforLiquidStoragewithDifferentCrustFormation

TypeofLiquidStorage EFN2O,man(gN2O/m2/day)

Uncoveredliquidmanurewithcrust 0.8

Uncoveredliquidmanurewithoutcrust 0

Coveredliquidmanure 0Source:Rotzetal.(2011a).

Equation5‐34:CalculatingN2OEmissionsfromLiquidManureStorage

Where:


EFN2O =EmissionrateofN2O(gN2Om‐2day‐1)

Asurface =Exposedsurfaceareaofthemanurestorage(m2)

1,000 =Conversionfactorforgramstokilograms


5-91

5.4.5 AnaerobicDigesterwithBiogasUtilization

5.4.5.1 OverviewofAnaerobicDigesterwithBiogasUtilization

OneofthemostcommonlydiscussedwastemanagementalternativesforGHGreductionandenergygenerationisanaerobicdigestion.Anaerobicdigestionisanatural,biologicalconversionprocessthathasbeenproveneffectiveatconvertingwetorganicwastesintobiogas(approximately60percentCH4and40percentCO2).Biogascanbeusedasafuelsourceforengine‐generatorsets,producingrelativelycleanelectricitywhilealsoreducingsomeoftheenvironmentalconcernsassociatedwithmanure.Thedigestercanbeassimpleasacoveredanaerobiclagoon(Gould‐WellsandWilliams,2004)orassophisticatedasthermophilicormediamatrix(attachedgrowth)digesters(Cantrelletal.,2008a).Thereareawidevarietyofanaerobicdigestionconfigurations,suchascontinuousstirredtankreactor(CSTR),coveredlagoon,plug‐flow,temperaturephased,upflowanaerobicsludgeblanket(UASB),packed‐bed,andfixedfilm.Thedigestionisalsocategorizedbasedonculturetemperature:thermophilicdigestioninwhichmanureisfermentedatatemperatureofaround55°C,ormesophilicdigestionatatemperatureofaround35°C.Amongthesetechnologies,CSTR,plug‐flow,andcoveredlagoon,allundermesophilicconditions,arethemostoften‐usedmethods.

Duringanaerobicdigestion,agroupofmicrobesworktogethertoconvertorganicmatterintoCH4,

CO2,andothersimplemolecules.Themainadvantagesofapplyinganaerobicdigestiontoanimalmanuresareodorreduction,electricitygeneration,andthereductionofGHGemissionsandmanure‐bornepathogens.Anaerobicdigestionisalsoanexcellentpre‐treatmentprocessforsubsequentmanuretreatmenttoremoveorganicmatterandconcentratephosphorus.ConsideringthesmallamountofN2Oexistinginbiogas,N2Oemissionsarenotestimatedfortheanaerobicdigestionofliquidmanure.

Thechallengesassociatedwithanaerobicdigestionrelatetoinitialcapitalcost,operation,andmaintenanceandothergasesthatmaybegenerated(e.g.,nitricoxides).Theeconomicsrelatetoaccesstotheelectricalgridandsufficientgreen‐electricityoffsetstomaketheoperationprofitable.Profitableconditionsarerelativelyscarce.Finally,thedigestersludgemustbemanaged.Anotherconversionalternativewithenergycreationpotentialisthermochemicalconversion(Cantrelletal.,2008a).Systemsthatusethermochemicalconversionstosyngases,bio‐oil,andbiocharforelectricityandfuelareemerging,butarenotyetestablished.

SinceananaerobicdigestionsystemconvertsorganiccarboninmanureintoCH4andsubsequentlycombustsCH4intoCO2,theGHGemissionsfrommanureanaerobicdigestionoperationaremainly

MethodforEstimatingEmissionsfromManureStorageandTreatment–AnaerobicDigesterwithBiogasUtilization

Methane

IPCCTier2usingCleanDevelopmentMechanismEFsfordigestertypestoestimateCH4leakagefromdigesters.

AnaerobicdigestersystemsconvertorganicmatterinmanureintoCH4andsubsequentlycombustCH4intoCO2.

GasleakagefromdigestersisthemainsourceofGHGemission. LeakageofCH4fromtheanaerobicdigestersystemisestimated.

NitrousOxide N2Oleakagefromdigestersisfairlysmallandnegligible.


5-92

fromtheleakageofdigesters.TheleakageofCH4canbeestimatedbasedontheIPCCTier2approachincombinationwithtechnology‐specificemissionfactors.

5.4.5.2 RationaleforSelectedMethod

TheIPCCequationistheonlyavailablemethodforestimatingCH4emissionfromdigesters.Thismethodologybestdescribesthequantitativerelationshipamongactivitydataattheentitylevelandtakesintoaccountthespecifictechnologyemployed.


InordertoestimatetheCH4leakagefromanaerobicdigestion,thefollowinginformationisneeded:

Animaltype Totaldrymanureintothedigester Volatilesolidsinthemanure Digestertemperatures


AncillarydataforanaerobicdigestioneffluentareneededforfurtherestimationofCH4andN2Oemissionsfrompost‐treatmentapproachessuchasaerobicoranaerobiclagoons,nutrientremovaloperations,etc.Thus,thenecessarydatafortheeffluentincludeeffluentflowrate,totalsolids,volatilesolids,chemicaloxygendemand,effluenttemperature,environmentaltemperature,liquid/solidseparationmethods,andtotalnitrogen.

5.4.5.5 Method

Equation5‐35describestheIPCCTier2approachforestimatingCH4emissionsforanaerobicdigesters.TheCH4generatedfromdigestersisassumedtobeflaredorusedasabiogas;theonlyemissionsfromdigestersarefromsystemleakage.

TheB0valuesareobtainedfromtheIPCC(2006)andarelistedinTable5‐19.TheemissionfactorsfortheamountofCH4leakagebytechnologyarelistedinTable5‐30.

Equation5‐35:IPCCTier2ApproachforEstimatingCH4 Emissions

.,

Where:

ECH4 =CH4emissionsperday(kgCH4day‐1)

m =Totaldrymanureperday(kgday‐1)


B0 =MaximumCH4producingcapacityformanurefromdifferentanimal (m3CH4(kgVS)‐1)

0.67 =Conversionfactorfromweighttovolumeofmethane(kgCH4m‐3)

EFCH4,leakage=EmissionfactorforthefractionofCH4producedthatleaksfromtheanaerobicdigester(%)


5-93

Table5‐30:EmissionFactorsfortheFractionofMethaneLeakingfromDigesters

DigesterConfigurations EFCH4,leakage(%)

Digesterswithsteelorlinedconcreteorfiberglassdigesterswithagasholdingsystem(eggshapeddigesters)andmonolithicconstruction

2.8

UASBtypedigesterswithfloatinggasholdersandnoexternalwaterseal 5Digesterswithunlinedconcrete/ferrocement/brickmasonryarchedtypegasholdingsection;monolithicfixeddomedigesters 10

Otherdigesterconfigurations 10Source:CDM(2012).

5.4.6 CombinedAerobicTreatmentSystems

Dealingwiththetotaltreatmentofwastewaterfromeitherswineordairyiscomplex,becausetheliquidandsolidphasesmustbetreated.Inmunicipalsewagetreatmentsystems,thewastewaterisverydilutesothetreatmentofthebiochemicaloxygendemandbyaerationisafundamentalprocess.Incontrast,thesolidscontentoflivestockwastewaterisquitehigh,asisthebiochemicaloxygendemand.Consequently,thecostofstabilizingthebiochemicaloxygendemandwithaerationhasproventobeuneconomical.AsuccessfulsolutiontothisproblemwasdevelopedbyVanottietal.(2007),whousedpolyacrylamideflocculationtoremovemorethan90percentofthesolids(VanottiandHunt,1999;Vanottietal.,2002).Thesolidfractionwasthencomposted(Vanotti,2006).Theremainingliquidwastransferredtoaseparatedwatertankwhereitwassubsequentlyaerated(VanottiandHunt,2000;Vanottietal.,2007;VanottiandSzogi,2008).Duringthesetwophasesoftreatment,morethan90percentoftheGHGemissionsfromstandardanaerobiclagoontreatmentwereavoided(Vanottietal.,2008).Theavoidancewasachievedbyaerobictreatmentofthesolidsviacompostingandnitrification/denitrificationintheliquideffluent.

Afternitrification/denitrification,thetreatedeffluentmovestothesettlingtankandsubsequentlyintothephosphorustreatmentchamber.Herethewastewater,whichhaslowalkalinity,isamendedwithliquidlime,andthepHisraisedtoapproximately10.InthepresenceofhighpHandcalcium,thephosphorusisprecipitatedandthepathogensarekilled(Vanottietal.,2003;Vanottietal.,2005;Vanottietal.,2009).Thetreatedwastewateristhenrecycledintothehouses.Thisprocessprovidesahealthierenvironmentforthepigs(Vanottietal.,2009).Thesystemmustbeoperatedtoensureproperandtimelyflushingofthehouse.Thepolyacrylamideadditionandthesolidsseparationunitsmustbeoperatedproperly.Aerationofthenitrificationtankmustbemaintained,asmusttheadditionofliquidlime.Thepumpsthatmaintaintheinternalrecyclingmustalsobemaintainedandoperatedcorrectly.ThissystemistheonlytreatmentsystemtomeetandbecertifiedforexpansionofswineproductioninNorthCarolina.

MethodforEstimatingEmissionsfromCombinedAerobicTreatmentSystems

Methodistoutilize10percentoftheemissionsresultingfromestimationofemissionsfromLiquidManureStorageandTreatment–AnaerobicLagoons,RunoffHoldingPonds,andStorageTanks.

Methodbasedonresearchfindingsthatsystemsavoid90percentoftheGHGemissionsfromstandardanaerobiclagoontreatment.


5-94

Toestimateemissionsforcombinedaerobictreatmentsystems,themethodologyforanaerobiclagoons,runoffholdingponds,andstoragetanksisappliedtothesystem.GasemissionsofCH4andN2Oareestimatedusing10percentofthevaluesforemissionsfromanaerobiclagoontreatment.

5.4.7 Sand‐ManureSeparation

Sandisoneofthestandardmaterialsfordairycowbedding.Itprovidessuperiorcowcomfort,environmentforudderhealth(andconsequentlybettermilkquality),andtractionwhencomparedwithorganicbeddingmaterials.Sandseparationsystemscanbeclassifiedasmechanicalseparationandsedimentationseparation.Sedimentationseparationusesdilutionwaterandgravitytoallowsandtopassivelysettleinsandtraps.Duetothehighorganicmaterialcontentcontainedinthesettledsand,thesandrecoveredfromthesandtrapneedstobedrainedmultipletimesanddriedpriortoreuse.Mechanicalsand‐manureseparationsystemsuserecycledliquidmanureandaerationtosuspendmanuresolids,settlesandatthebottomoftheseparator,andrecoverthesandusingaheavydutyauger.Sandisgenerallydischargedwithlessthantwopercentorganicmatter.Themechanicallyseparatedsandcanbereusedforbedding.

Sincesand‐manureseparationisrelativelyquick(comparedwithotherstorageandtreatmentmethods),GHGemissionsfromtheoperationareminimal.TheprocessofseparatingsandandmanureisnotassumedtocontributetoGHGemissions.Aftersand‐manureseparation,theseparatedliquidmanureistreatedastheinfluentforthenextstepofstorageandtreatmentoperations.ThevariousstorageandtreatmentoperationoptionsareshowninFigure5‐7.Theparametersofvolatilesolids,totalnitrogen,organicnitrogen,andmanuretemperatureoftheseparatedliquidmanureshouldbemeasured,andusedastheinputstoestimateemissionsofGHGs.

5.4.8 NutrientRemoval

Nitrogenandphosphorusaretheprimaryelementsthatcauseeutrophicationinsurfacewaters.WithincreasedFederal,Stateandlocalattentiononnon‐pointwastesources,moreandmoreanimaloperationswilllikelyusenutrientremovalapproachestotreatliquidmanurebeforelandapplicationandotheruses.Comparedtophosphorus,nitrogeninmanurecontributestoN2Oemission;removingitcansignificantlyalleviateemissions.NitrogeninmanurecomprisesNH3,particulateorganicnitrogen,andsolubleorganicnitrogen.Fivemainnitrogenremoval

MethodforEstimatingEmissionsfromLiquidManureStorageandTreatment–Sand/ManureSeparation

NomethodisprovidedasGHGemissionsarenegligiblefromthesand/manureseparationprocess.However,resultingvolatilesolids,totalnitrogen,organicnitrogen,andmanuretemperatureoftheseparatedliquidmanureshouldbemeasuredandusedastheinputstoestimateemissionsofGHGsforsubsequentstorageandtreatmentoperations.

MethodforEstimatingEmissionsfromLiquidManureStorageandTreatment–NutrientRemoval

NotestimatedduetolimitedquantitativeinformationonGHGsfromnitrogenremovalprocesses.


5-95

approaches—BiologicalNitrogenRemoval(BNR),Anamox,NH3stripping,ionexchange,andstruvitecrystallization—havebeenappliedformunicipalandindustrialwastewater,aswellasforanimalwastestreams.BecauseN2Ooriginatesfromnitrogensources,quantificationofnitrogenremovalisimportanttoestimateemissionsfromanimalmanure.

Becausemostnitrogenremovalmethodsforliquidmanurearecurrentlyintheresearchanddevelopmentstage,verylittlequantitativeinformationisavailableonthenitrogenremovalmethodsmentionedaboveforanimalmanureunderdifferentoperationconditions.Thesuggestedestimationmethodistoconsidertheliquidmanureafternutrientremovalastheinfluentforstorageandtreatmentapproachesthatentitieswillusetofurthertreatliquidmanure.Measurementsofvolatilesolids,totalnitrogen,organicnitrogen,andmanuretemperatureofthetreatedliquidmanureareneededtoestimateCH4andN2Oemissions.

5.4.9 Solid–LiquidSeparation

Solid–liquidmanureseparationhasbeenusedwidelybydairyfarms.Onepurposeofsolid–liquidseparationistophysicallyseparateandremovethelargersolidsfromliquidmanureinordertostoreandtreatthemseparately.Theavailablecommercialmethodsincludegravitysedimentationandmechanicalseparation(withorwithoutcoagulationflocculation).Sedimentationandmechanicalseparationwithoutcoagulationflocculationarethemostpopularmethodsusedbyanimalfarms.Similartosand–liquidmanureseparation,GHGemissionsfromtheoperationareminimal;however,separationhasanimpactonnutrientdistributioninseparatedsolidandliquidmanure,whichwillinfluenceGHGemissionsfromthenextstageofmanurestorageandtreatmentforsolidandliquidmanure.Theseparatedliquidmanureistreatedastheinfluentforthenextstepofstorageandtreatmentoperations.ThepossiblestorageandtreatmentoptionsaredelineatedinFigure5‐7.

Theparametersoftotalsolids(drymanure),totalnitrogen,organicnitrogen,andmanuretemperatureoftheseparatedliquidandsolidmanureshouldbemeasured,andusedastheinputstoestimateGHGsemissioninthesubsequentstorageandtreatmentoperations.Thedistributionoftotalsolidsaftersolid–liquidseparationfortypicalmechanicalseparatorsarelistedinTable5‐317(FordandFleming,2002).

Table5‐31:EfficiencyofDifferentMechanicalSolid‐LiquidSeparation

SeparationTechnique

ManureType

ScreenSize(mm)

Influent(%DM)

TotalSolidRemoval

Efficiency(%)Source

ScreenStationaryinclinedscreen

Swine 1.0 0.0‐0.7 35.2 Shuttetal.(1975)Beef 0.5 0.97‐4.41 1‐13 Heggetal.(1981)Dairy 1.5 3.83 60.9 Chastainetal.(2001)

Vibratingscreen

Swine 0.39 0.2‐0.7 22.2 Shuttetal.(1975)Beef 0.52‐1.91 5.5‐7.4 4‐44 GilbertsonandNienaber(1978)

MethodforEstimatingEmissionsfromLiquidManureStorageandTreatment–Solid–LiquidSeparation

NomethodisprovidedasGHGemissionsarenegligible.However,resultingvolatilesolids,totalnitrogen,organicnitrogen,andmanuretemperatureoftheseparatedliquidandsolidmanureshouldbemeasuredandusedastheinputstoestimateemissionsofGHGsandNH3forsubsequentstorageandtreatmentoperations.


5-96

SeparationTechnique

ManureType

ScreenSize(mm)

Influent(%DM)

TotalSolidRemoval

Efficiency(%)Source

Beef 0.64‐1.57 1.55‐3.19 6‐16 Heggetal.(1981)Dairy 0.64‐1.57 0.95‐1.9 8‐16 Heggetal.(1981)Swine 0.64‐1.57 1.55‐2.88 3‐27 Heggetal.(1981)Swine 0.10‐2.45 1.5‐5.4 11‐67 Holmbergetal.(1983)

Rotatingscreen

Beef 0.75 1.56‐3.68 4‐6 Heggetal.(1981)Dairy 0.75 0.52‐2.95 0‐14 Heggetal.(1981)Swine 0.75 2.54‐4.12 4‐8 Heggetal.(1981)

In‐channelflightedconveyorscreen

Dairy 3 7.1 4.22 Mølleretal.(2000)

Swine 3 5.66 25.8 Mølleretal.(2000)CentrifugalCentrifuge Beef 7.5 25 Glerumetal.(1971)Centrisieve Swine 5‐8 30‐40 Glerumetal.(1971)

Decantercentrifuge

Beef 6.9 64 Chiumentietal.(1987)Beef 6.0 45 Chiumentietal.(1987)Swine 7.58 66 Glerumetal.(1971)Swine 1.9‐8.0 47.4‐56.2 Sneathetal.(1988)

Liquidcyclone

Swine 26.5 Shuttetal.(1975)

Filtration/pressing

RollerpressSwine 5.2 17.3 Posetal.(1984)Dairy 4.8 25 Posetal.(1984)Beef 4.5 13.3 Posetal.(1984)

BeltpressDairy 1‐2 7.1 32.4 Mølleretal.(2000)Swine 1‐2 5.7 22.3 Mølleretal.(2000)

Screwpress

Swine 5 16 Chastainetal.(1998)Swine 1‐5 15‐30 Converseetal.(1999)Dairy 1‐10 15.8‐47 Converseetal.(1999)Dairy 2.6 23.8 Converseetal.(1999)Dairy 4.9 33.4 Converseetal.(1999)

Fournierrotarypressa

Swine 85 FordandFleming(2002)Fournier(2010)

Rotaryvacuumfilter Swine 7.5 51 Glerumetal.(1971)

Pressurefilter Beef 7 76 Chiumentietal.(1987)ContinuousBeltMicroscreeningUnit

Swine 2‐8 40‐60 Fernandesetal.(1988)aWithpolymeraddition.


5-97

5.4.10 ConstructedWetland

Globally,constructedwetlandsareusedforthetreatmentofwastewaters,captureofsediments,

anddrainagewaterabatement(Hammer,1989;KadlecandKnight,1996;Tanneretal.,1997;Huntetal.,2002;Huntetal.,2003;Piceketal.,2007;HarringtonandMcInnes,2009;Mustafaetal.,2009;Soosaaretal.,2009;Elgoodetal.,2010;HarringtonandScholz,2010;VanderZaagetal.,2010;Chenetal.,2011;Lockeetal.,2011;TannerandHeadley,2011;TannerandSukias,2011;Vymazal,2011).Constructedwetlandsaregenerallyclassifiedassub‐surfaceorsurfaceflowwetlands(KadlecandKnight,1996).Thesub‐surfacewetlandstypicallyconsistofwetlandplantsgrowinginabedofhighlyporousmedia,suchasgravelorwoodchips.Theyarecommonlyusedtoimprovedrainagewaterquality.Thesewetlandsaregenerallyrectangularinshapeandonetotwometersindepth.Thereislackofagreementabouttherelativeimpactofmicrobialandplantprocessesinthefunctionofsubsurfacewetlands,includingGHGproductionandemissions.However,itisaccuratetosaythatplantsandmicrobesaretypicallyinterdependentlyinvolved(Piceketal.,2007;Zhuetal.,2007;Wangetal.,2008;Faubertetal.,2010;Luetal.,2010;TannerandHeadley,2011).Themicrobialcommunityadvancesbiogeochemicalprocesses(Tanneretal.,1997;Huntetal.,2003;Zhuetal.,2007;Dodlaetal.,2008;Faulwetteretal.,2009),whiletheplantcommunityadvancestransportedoxygenintothedepthofthewetlands,providesrootsurfacesforrhizospherereactions,andventsgasestotheatmosphere.Theplantprocessesaresignificantlyaffectedbyplantcommunitycompositionandweatherconditions(Towleretal.,2004;SteinandHook,2005;Steinetal.,2006;Zhuetal.,2007;Wangetal.,2008;Tayloretal.,2010).

Surfaceflowwetlandshaveamuchmoredirectinterchangewiththeatmosphereforthesupplyofoxygenandnitrogen,aswellastheemissionsofGHGs.Theycanbevariableinshapeandaregenerallylessthan0.5metersdeep.Surfacewetlandsminimizecloggingproblems,buttheycanhavesignificantlossoftreatmentasaresultofchannelflow.Therearereasonablyfunctionalmodelsforwetlanddesignoptimizedforeithercarbonornitrogenremoval(Stoneetal.,2002;Stoneetal.,2004;Steinetal.,2006;Steinetal.,2007a).ThemanagementofGHGs(principallyCH4andN2O)fromtreatmentwetlandsissomewhatsimilartomanagingGHGsinrice(Freemanetal.,1997;Tanneretal.,1997;Feyetal.,1999;Johanssonetal.,2003;Manderetal.,2005a;Manderetal.,2005b;TeiterandMander,2005;Piceketal.,2007;Maltais‐Landryetal.,2009;Wuetal.,2009).

Ofparticularimportanceisthemaintenanceofwetlandoxidative/reductivepotentialconditionssufficientlypositivetoavoidCH4production(Tanneretal.,1997;InsamandWett,2008;SeoandDeLaune,2010).Thisrequireshigherlevelsofoxygenandlowerlevelsofavailablecarbon.IthasbeenreportedthatthefluxesofN2OandCH4fromtreatmentwetlandsaregenerallybelow10mgN2O‐Nm‐2d‐1and300mgCH4‐Cm‐2d‐1(Manderetal.,2005a;Søviketal.,2006).ThemanagementofN2Oemissionsiscomplicatedbythefactthatnitratesareoftenpresentinthewastewatersordrainagewaters.Thisnitratewillbedenitrifiedundertheprevailinganaerobicconditionofthetreatmentwetlands—itisoneoftreatmentwetland’scriticalfunctions.However,itisimportantthatthepreponderanceofdenitrificationproceedstocompletion,withtheultimateproductionofinertdi‐nitrogengas.Completedenitrificationrequireshighercarbon/nitrogenratios

MethodforEstimatingEmissionsfromLiquidManureStorageandTreatment–ConstructedWetland

Currentlynomethodisprovidedtoestimategasemissionfromconstructedwetlandofanimalmanure,althoughGHGsinksarenotedtolikelybegreaterthanCH4andN2Oemissions,whichareconsiderednegligible.


5-98

(Klemedtssonetal.,2005;Hwangetal.,2006;Huntetal.,2007).Thus,thereisanimportantbalancebetweensufficientcarbonforcompletedenitrificationandcopiouscarbonthatcandrivewetlandsintothelowreduction/oxidationconditionsassociatedwithCH4production.

Estimationmethodsareverycomplicatedandcase‐based.Inanapproximateestimationmannerthatconsiderswetlandsverysimilartocropland,treatmentwetlandsofanimalmanureareGHGsinksmorethansources.TheCH4andN2Oemissionfromwetlandtreatmentofanimalmanurecouldbenegligible.Thecriticalactivitydataincludehydraulicload;inflowwatercomposition,especiallycarbonandnitrogen;pretreatmentssuchassolidsremovalornitrification;amendments;anddryingcycles.Criticalancillarydataincluderainfall,temperature,windspeed,stormevents,changesinlivestockstockingrates,cropping/tillagesystems,andfertilizationtiming/rates.

5.4.11 Thermo‐ChemicalConversion

Combustion,themostprimitiveandexothermicformofthermochemicaltreatmentoflivestockwaste,hasbeeninusesinceantiquity;however,itsuseforlarge‐scalelivestockwastetreatmenthasgenerallybeenhamperedbyeconomic,health,andenvironmentalqualityissues(Florinetal.,2009).Principalamongtheseissueshasbeencomponentsthatdegradeairquality,includingGHGs(mainlyCO2).Nonetheless,thermochemicaltreatmentoflivestockmanurehasattributesthatcontinuetoattracteffortstomakeiteconomicallyandenvironmentallyeffective(Ramanetal.,1980;Heetal.,2000;Heetal.,2001;Ocfemiaetal.,2006;Roetal.,2007;Cantrelletal.,2008a;Cantrelletal.,2008b;Powlsonetal.,2008;Cantrelletal.,2009;Dongetal.,2009;Jinetal.,2009;Roetal.,2009;Xiuetal.,2009;Cantrelletal.,2010a;Cantrelletal.,2010b;Stoneetal.,2010;Wangetal.,2011;Xiuetal.,2011).

Recently,pyrolysis/gasificationhasreceivedmuchinterestforitstreatmentoflivestockwaste.Therehavealsobeenadvancesinthecleaningofexhaustgases(Heetal.,2001;Roetal.,2007;Cantrelletal.,2008a;Dongetal.,2009;Xiuetal.,2009;Xiuetal.,2011).Pyrolysis/gasificationoffersthreeprincipalendproducts:syngas,bio‐oil,andbiochar(Cantrelletal.,2008a;Xiuetal.,2011).Thequalityandquantityofendproductswillvarywithfeedstock,exposuretime,andpyrolysis/gasificationtemperature.Thesyngascanbeusedfordirectcombustionortorunanelectricalgenerator(Roetal.,2010).ItcanalsobeusedviaFischer‐Tropschconversionforproductionofliquidfuel(Cantrelletal.,2008a).Pyrolysis/gasificationforsyngasandeventualliquidfuelproductionisaveryattractivepotentialbusinessmodelforspecificagriculturalfuels.

IntermsofGHGemission,treatmentoffluegasfromcombustionandutilizationofsyngasfrompyrolysis/gasificationarecritical.Thethermalprocesseswithafluegasclean‐upunitandsyngasutilizationunitshouldminimizetheGHGemissionfromthethermalconversionprocesses.

InordertoestimatethedailyemissionsofCH4andN2Othefollowinginformationisneeded:typeofthermalconversionprocesses;detailedinformationontheprocess,suchaswith/withoutfluegasclean‐upunitorsyngasutilizationunit;inflowcomposition,suchasmoisture,carbon,andnitrogen;andmassflowthroughtheprocess,includingmassin,fluegas/syngas,andash/biochar.Themeasurementscanbebasedondietarychangesorseasonaltimeframe,whichisdecidedbyindividualfarmentity.However,duetothedynamicnatureofmanurepilesandtherapidchangesthatcanoccurinchemicalandphysicalcomposition,frequentmeasurementsarerecommendedtoensureaccuracyoftheestimation.Thetotalenergybalanceofthesystemshouldalsobeknown.For

MethodforEstimatingEmissionsfromSolidManureStorageandTreatment–ThermochemicalConversion

NomethodisprovidedasCH4andN2Oemissionsareconsiderednegligible.


5-99

instance,thecarboncreditsofbiocharcannotbeclaimedwhileignoringtheenergyrequiredtocreatethebiochar.Theeffectivenessoftheexhaustgascleaningprocessinremovingairqualitydegradingcomponentsmustbecertified.

Duetothenatureofthermalconversion,muchloweremissions(CH4andN2O,)aregeneratedfromthethermalconversioncomparedwithotherstorageortreatmentmethods.TheCH4andN2Oemissionsfromcompletethermalconversionprocessesarerelativelysmallandnegligible.

5.4.12 LimitationsandUncertaintyinManureManagementEmissionsEstimates

Fortemporaryandlong‐termstorage,composting,andaerobiclagoons,theIPCCTier2methodologyisusedtoestimateCH4emissions.ThemaximumCH4productioncapabilities(B0)forruminantanimalsareU.S.specificvaluesfromtheU.S.EPAInventoryofU.S.GHGEmissionsandSinks.IPCCestimatesthattheuncertaintyassociatedwiththesecountry‐specificfactorsis±20percent.B0valuesforotheranimalvaluesareIPCCdefaultsandhaveanassociateduncertaintyof±30percent.TheMCFsprovidedintheGuidelinesforsolid,slurry,andsolid/slurrymanurearefromtheIPCCGuidanceandhaveanestimateduncertaintyof±30percent.TheB0andMCFvaluesprovidedareintendedforuseatthenationallevel,thusapplicationofthesefactorsattheentitylevelmayresultinhigheruncertainty.

AmodifiedTier2approachisprovidedforestimatingCH4emissionsfromanaerobicdigesters.TheleakratesfordifferentdigestertypesistakenfromtheCleanDevelopmentMechanism’smethodologicaltoolforprojectandleakageemissionsfromanaerobicdigesters(CDM,2012).TheCleanDevelopmentMechanism’sleakratesarebasedonIPCC(2006),Fleschetal.(2011),andKurup(2003).TheleakageratetakenfromFleschetal.(2011)isbasedonmeasurementstakenfromanIntegratedManureUtilizationSysteminstalledinAlberta,Canada.Thesystemprocesses100metrictonsofmanuredailyandwasthemosttechnologicallyadvancedsystemavailableatthetimeofthestudy.ThestudiesperformedbyKurup(2003)werebasedonasystemlocatedinKerala,India.Nouncertaintyestimatesareprovidedfortheseleakrates;however,theactualleakrateofanentitymaydifferduetodifferencesintechnology,maintenance,orotherfactors.

TheSommermodel(Sommeretal.,2004)isrecommendedforestimatingCH4emissionsfromanaerobiclagoons,runoffholdingponds,andstoragetanks.SimilartotheIPCCTier2methodsusedforstockpiles,composting,andaerobiclagoons,theSommermodelrequiresB0valuesfromIPCC.ThedegradableandnondegradablevolatilesolidscanbecalculatedusingtheB0andpotentialCH4yieldoradefaultvaluefromMølleratal.(2004).ThedefaultvaluespresentedarebasedontypicalconcentrationsonDanishcattleandpigslurries;valuesdonotdifferentiatebetweentypeofcattleordietoftheanimalandthusthereishigherrelativeuncertaintyassociatedwithusingthedefaultvalues.

Sommeretal.(2004)performedananalysistodeterminethesensitivityofemissionestimatestowardsdifferentfactors.OnefactorconsideredistheeffectofslurrystoragetemperatureonCH4emissions.Sommeretal.(2004)appliedaveragemonthlytemperaturesforsevendifferentlocations(allNordiccountries)atconstantvolatilesolidsandmanagement.WhencomparedtothemodelresultsforDenmark(whicharecalibratedtocorrespondwithIPCCmethodology),theemissionsestimatesvariedfrom‐1to+36percentforpigslurryand‐23to+1percentforcattleslurry.GiventhattheclimaticconditionsoftheUnitedStatesdiffersfromNordiccountries,thevariationasaresultofslurrystoragetemperatureisexpectedtobegreater.

IPCCmethodologyormodifiedmethodologyisusedtoestimatetheN2Oemissionsfromtemporarystackandlong‐termstorage,composting,andaerobiclagoons.IPCCreportslargeuncertaintieswiththedefaultemissionfactorsapplied(‐50percentto+100percent).Theseemissionfactorswereintendedforuseatthenationallevelanddonottakeintoaccountvaryingtemperature,moisture


5-100

content,aeration,manurenitrogencontent,metabolizablecarbon,durationofstorage,andotheraspectsoftreatmentfordifferententities,thustheuncertaintyisexpectedtobehigherthanreportedbyIPCC.

Themethodsrecommendthattheusersendmanuresamplestoalaboratorytoobtainanestimateofthevolatilesolids,NH3,andnitrogencontentofmanure.Ameasurementofmanurecharacteristicscanhelpminimizeuncertaintybyprovidinganentity‐specificvaluethattakesintoaccountanimalanddietcharacteristics.Iflaboratory‐testedvolatilesolidsvaluesarenotavailable,defaultvaluesfromtheAmericanSocietyofAgriculturalandBiologicalEngineers(ASABE)canbeapplied.ASABEprovidesdefaultmanurecharacteristicsbasedondatafrompublishedandunpublishedinformation.Thesevaluesarearithmeticaveragesandmaynotrepresentthedifferencesinanimalage,diet,usage,productivity,andmanagement.ThereisahigheramountofuncertaintyassociatedwiththeuseofASABEvaluesbutthereisnoquantifieduncertaintyprovidedforthesevalues.Notethatwithinthestandardcitedbelowthereareequationsprovidedthatallowforfarm‐specificvaluestobedeterminedbasedonanimalcharacteristicsanddietcomposition.Thetablebelowisintendedtoprovide‘average’values,butwherefarmdataareavailable,equationsshouldbeusedinordertoprovidemoreestimatesthatbetterreflectfarmconditionsandpractices.

AvailabledefaultvaluesanduncertaintyinformationisincludedinTable5‐32.

Table5‐32:AvailableUncertaintyDataforEmissionsfromManureManagement

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue

RelativeuncertaintyLow

(%

)

RelativeuncertaintyHigh

(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

TotalDryManure–BeefFinishingCattle

kgdrymanure/animal/day 2.4 ‐20 20 ASABE(2005)

TotalDryManure–BeefCow(confinement)


TotalDryManure–BeefGrowingcalf(confinement)


TotalDryManure–DairyLactatingcow

kgdrymanure/animal/day 8.9 ‐20 20 8.7 11.3 ASABE(2005)

TotalDryManure–DairyDrycow kgdrymanure/animal/day 4.9 ‐20 20 8.8 11.2 ASABE(2005)

TotalDryManure–DairyHeifer kgdrymanure/animal/day 3.7 ‐20 20 ASABE(2005)

TotalDryManure–DairyVeal118kg kgdrymanure/animal/day 0.12 ‐20 20 ASABE(2005)

TotalDryManure–HorseSedentary500kg


TotalDryManure–HorseIntenseexercise500kg


TotalDryManure–PoultryBroiler kgdrymanure/animal/day 0.03 ‐20 20 ASABE(2005)TotalDryManure–PoultryTurkey(male)


TotalDryManure–PoultryTurkey(females)


TotalDryManure–PoultryDuck kgdrymanure/animal/day 0.04 ‐20 20 ASABE(2005)TotalDryManure–Layer kgdrymanure/animal/day 0.02 ‐20 20 ASABE(2005)TotalDryManure–SwineNurserypig(12.5kg)



5-101

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

TotalDryManure–SwineGrowfinish(70kg)


TotalDryManure–Swinegestatingsow200kg


TotalDryManure–SwineLactatingsow192kg


TotalDryManure–SwineBoar200kg


Volatilesolids–BeefFinishingcattle VS kgVS/kgdrymanure 0.81 ‐25 25 ASABE(2005)Volatilesolids–BeefCow(confinement)

VS kgVS/kgdrymanure 0.89 ‐25 25 ASABE(2005)

Volatilesolids–BeefGrowingcalf(confinement)


Volatilesolids–DairyLactatingcow VS kgVS/kgdrymanure 0.84 ‐25 25 ASABE(2005)Volatilesolids–DairyDrycow VS kgVS/kgdrymanure 0.85 ‐25 25 ASABE(2005)Volatilesolids–DairyHeifer VS kgVS/kgdrymanure 0.86 ‐25 25 ASABE(2005)

Volatilesolids–DairyVeal118kg VS kgVS/kgdrymanure ‐25 25 ASABE(2005)

Volatilesolids–HorseSedentary500kg


Volatilesolids–HorseIntenseexercise500kg


Volatilesolids–PoultryBroiler VS kgVS/kgdrymanure 0.73 ‐25 25 ASABE(2005)Volatilesolids–PoultryTurkey(male)


Volatilesolids–PoultryTurkey(females)


Volatilesolids–PoultryDuck VS kgVS/kgdrymanure 0.58 ‐25 25 ASABE(2005)Volatilesolids–Layer VS kgVS/kgdrymanure 0.73 ‐25 25 ASABE(2005)Volatilesolids–SwineNurserypig(12.5kg)


Volatilesolids–SwineGrowfinish(70kg)


Volatilesolids–Swinegestatingsow200kg


Volatilesolids–SwineLactatingsow192kg


Volatilesolids–SwineBoar200kg VS kgVS/kgdrymanure 0.89 ‐25 25 ASABE(2005)Totalnitrogenatagivenday–beeffinishingcattle

kgN/kgdrymanure 0.07 ASABE(2005)

Totalnitrogenatagivenday–beefcow(confinement)


Totalnitrogenatagivenday–beefgrowingcalf(confinement)


Totalnitrogenatagivenday–dairylactatingcow


Totalnitrogenatagivenday–dairydrycow


Totalnitrogenatagivenday–dairyheifer


Totalnitrogenatagivenday–dairyveal118kg


Totalnitrogenatagivenday–HorseSedentary500kg


Totalnitrogenatagivenday–HorseIntenseExercise



5-102

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

Totalnitrogenatagivenday–poultry,broiler


Totalnitrogenatagivenday–poultry,turkey(male)


Totalnitrogenatagivenday–poultry,turkey(females)


Totalnitrogenatagivenday–poultry,duck


Totalnitrogenatagivenday–layer kgN/kgdrymanure 0.07 ASABE(2005)Totalnitrogenatagivenday–swinenurserypig(12.5kg)


Totalnitrogenatagivenday–swinegrowfinish(70kg)


Totalnitrogenatagivenday–swinegestatingsow200kg


Totalnitrogenatagivenday–swinelactatingsow192kg


Totalnitrogenatagivenday–swineboar200kg


MethaneConversionFactor(MCF)a–DairyCow

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Cattle MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Buffalo MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–MarketSwine

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–BreedingSwine

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Layer(Dry)

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Broiler MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Turkey MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Duck MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Sheep MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Goat MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Horse MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Mule/Ass

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Buffalo MCF % ‐30 30 IPCC(2006)MethaneConversionFactora–Invesselmanurecomposting

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Staticpilemanurecomposting

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Intensivewindrow

MCF % ‐30 30 IPCC(2006)

MethaneConversionFactora–Passivewindrow

MCF % ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–BeefReplacementHeifers

Bo m3CH4/kgVS 0.33 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–DairyReplacement Bo m3CH4/kgVS 0.17 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–MatureBeefCows

Bo m3CH4/kgVS 0.33 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–Steers(>500lbs)

Bo m3CH4/kgVS 0.33 ‐20 20 U.S.EPA(2011)


5-103

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

MaximumMethaneProducingCapacities–Stockers(All)

Bo m3CH4/kgVS 0.17 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–CattleonFeed

Bo m3CH4/kgVS 0.33 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–DairyCow

Bo m3CH4/kgVS 0.24 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–Cattle

Bo m3CH4/kgVS 0.19 ‐20 20 U.S.EPA(2011)

MaximumMethaneProducingCapacities–Buffalob

Bo m3CH4/kgVS 0.1 IPCC(2006)

MaximumMethaneProducingCapacities–MarketSwine Bo m3CH4/kgVS 0.48 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–BreedingSwine

Bo m3CH4/kgVS 0.48 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Layer(dry) Bo m3CH4/kgVS 0.39 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Layer(wet)

Bo m3CH4/kgVS 0.39 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Broiler Bo m3CH4/kgVS 0.36 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Turkey

Bo m3CH4/kgVS 0.36 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Duck Bo m3CH4/kgVS 0.36 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Sheep

Bo m3CH4/kgVS 0.19 ‐20 20 IPCC(2006)

MaximumMethaneProducingCapacities–Feedlotsheep Bo m3CH4/kgVS 0.36 ‐20 20 IPCC(2006)

MaximumMethaneProducingCapacities–Goat

Bo m3CH4/kgVS 0.17 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Horse Bo m3CH4/kgVS 0.3 ‐30 30 IPCC(2006)

MaximumMethaneProducingCapacities–Mule/Ass

Bo m3CH4/kgVS 0.33 ‐30 30 IPCC(2006)

EmissionfactorforthefractionofCH4producedthatleaksfromtheanaerobicdigester–Digesterswithsteelorlinedconcreteorfiberglassdigesterswithagasholdingsystem(eggshapeddigesters)andmonolithicconstruction

EFCH4,leakage

% 2.8 CDM(2012)

EmissionfactorforthefractionofCH4producedthatleaksfromtheanaerobicdigester–UASBtypedigesterswithfloatinggasholdersandnoexternalwaterseal

EFCH4,leakage

% 5 CDM(2012)

EmissionfactorforthefractionofCH4producedthatleaksfromtheanaerobicdigester–Digesterswithunlinedconcrete/ferrocement/brickmasonryarchedtypegasholdingsection;monolithicfixeddomedigesters

EFCH4,leakage

% 10 CDM(2012)


5-104

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

EmissionfactorforthefractionofCH4producedthatleaksfromtheanaerobicdigester–Otherdigesterconfigurations

EFCH4,leakage

% 10 CDM(2012)

Temporarystorageofliquid/slurrymanure–N2Oemissionfactorc

EFN20 kgN2O‐N/kgN 0.005 ‐50 100 U.S.EPA(2011)

Long‐termstorageofsolidmanure–N2Oemissionfactorc


Long‐termstorageofslurrymanure–N2Oemissionfactorc


CattleandSwineDeepBedding(ActiveMix)‐N2Oemissionfactorc

EFN20 kgN2O‐N/kgN 0.07 IPCC(2006)

CattleandSwineDeepBedding(NoMix)‐N2Oemissionfactorc


PitStorageBelowAnimalConfinements‐N2Oemissionfactorc


Naturalaerationaerobiclagoons–N2Oconversionfactorc

EFN20 kgN2O‐N/kgN 0.01 ‐50 100 IPCC(2006)

Forcedaerationaerobiclagoons–N2Oconversionfactorc


N2Oemissionfactorforliquidstorage–uncoveredliquidmanurewithacrustc


N2Oemissionfactorforliquidstorage–uncoveredliquidmanurewithoutacrustc

EFN20 kgN2O‐N/kgN 0 ‐50 100 IPCC(2006)

N2Oemissionfactorforliquidstorage–coveredliquidmanurec

EFN20 kgN2O‐N/kgN 0 ‐50 100 IPCC(2006)

ManureManagement–MultipleSources–collectionefficiency,coveredstorage(withorwithoutcrust)

η Percentage 1 Sommeretal.(2004)

ManureManagement–MultipleSources–collectionefficiency,uncoveredstoragewithcrustformation

η Percentage 0

Sommeretal.(2004)

ManureManagement–MultipleSources–collectionefficiency,uncoveredstoragewithoutcrustformation

η Percentage ‐0.40

Sommeretal.(2004)

ManureManagement–MultipleSources–Ratecorrectingfactors(b1)

b1 Dimensionless 1 Sommeretal.(2004)

ManureManagement–MultipleSources–Ratecorrectingfactors(b2)

b2 Dimensionless 0.01Sommeretal.(2004)

ManureManagement–MultipleSources–Arrheniusparameter,cattle

A gCH4/kgVS/hr 43.33 Sommeretal.(2004)

ManureManagement–MultipleSources–Arrheniusparameter,swine

A gCH4/kgVS/hr 43.21Sommeretal.(2004)

Potentialmethaneyieldofthemanurecattle

ECH4,pot‐

kgCH4/kgVS 0.48 Sommeretal.(2004)

Potentialmethaneyieldofthemanure‐swine

ECH4,pot

kgCH4/kgVS 0.5Sommeretal.(2004)


5-105

Parameter

Abbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

Temporarystackandlong‐termstockpile–Ratiodegradablevolatilesolidstototalvolatilesolids‐cattleliquidmanure

VSd/VST

Unitless 0.46 Mølleretal.(2004)

Temporarystackandlong‐termstockpile–Ratiodegradablevolatilesolidstototalvolatilesolids‐swineliquidmanure

VSd/VST


Temporarystackandlong‐termstockpile–RatioNon‐degradablevolatilesolidstototalvolatilesolids‐cattleliquidmanure

VSnd/VST


Temporarystackandlong‐termstockpile–Rationon‐degradablevolatilesolidstototalvolatilesolids–swineliquidmanure

VSnd/VST


aThevaluesformethaneconversionfactor(MCF)varydependingonthetemperatureandthemanuremanagementsystem.IPCC(2006)providesestimateduncertaintyrangesfortheseMCFs.bTherearenodataforNorthAmericaregion;thedatafromWesternEuropeareusedtocalculatetheestimation.Thereisnoreporteduncertaintyforthisadaptedvalue.cIPCC(2006)reportslargeuncertaintieswithdefaultN2Oemissionfactors.TheN2OEFvaluesvarydependingontheanimalspeciesandtemperatureofthemanuremanagementsystem.

5.5 ResearchGaps

Researchgapshavebeenidentifiedforanimalproductionsystems,coveringactivitydata,aswellaskeyareasthatwouldfacilitatemoreaccurateestimationofemissionsfromentericfermentationandmanuremanagementsystems.Recommendationsarediscussedbelow.

5.5.1 EntericFermentation

CattleFutureresearchrelatedtoimprovingemissionsestimatesshouldbeaimedatexpandingtheoptionswithinexistingmodelstobetterdescribeanindividualfarmsystemandincorporatemoreoptionsformitigationstrategiestoseehowemissionsmightchangewithimplementationofthesestrategiesaswellasconsidertheinteractiveeffectsofmultiplestrategies.

BeefCow‐Calf,Bulls,Stocker,andSheepKeydataneedsincludemeasurement/predictionoffeedintakeonpasture,measurement/predictionofCH4fromgrazinganimals(largernumbersofanimals),andmethodsbywhichtocharacterizerangeforageandintakeunderproductionconditions.

FeedlotThereisaneedforequationsandmodelstoaccuratelypredictentericCH4emissionsfromcattleandsheepfedhigh‐concentratefinishingdiets.


5-106

DairyOneofthelargestresearchgapsisthelackofbasicdatarelatedtoemissionsfromcalves,heifers,anddrycowhousingsystems.Inaddition,thereisaneedforequallyconsistentandreliablemethodsformeasuringrelativedifferencesinemissionsassociatedwiththeimplementationofavarietyofmanagementpractices.Furthermodeldevelopmentforestimatingemissionsshouldincludeanexpansionofoptionstodescribetheproductionfacilityandinclusionofmanagementpracticesthatcanbeadoptedtomitigateemissions.

SwineFutureresearchrelatedtoimprovingemissionsestimatesshouldbeaimedatexpandingtheoptionswithinthesemodelstobetterdescribeanindividualfarmsystemandincorporatemoreoptionsformanagementandmitigationstrategiestoseehowemissionsmightchangewithimplementationofdifferentpractices.Minimally,thedietconsiderationsinHolosneedtobeincorporatedintotheMANUREmodelandexpandedtoreflectproductionphase.

PoultryFutureresearchrelatedtoimprovingemissionsestimatesshouldbeaimedatexpandingtheoptionswithinthesemodelstobetterdescribeanindividualfarmsystemandincorporatemoreoptionsformanagementandmitigationstrategiestoseehowemissionsmightchangewithimplementationofdifferentpractices.

5.5.2 ManureManagement

Greenhousegasemissionsfromavarietyofmanuremanagementsystemshavebeendevelopedfromalimitednumberofstudiesandalimitednumberofpotentialvariationsinmanagementandtheenvironmentalconditionsaroundaparticularmanuremanagementsystem.ThelargestdeficiencyinthecurrentGHGstudiesisthelackofcharacterizationofthetemporalvariationintheGHGemissionsfromdifferentsystemsandthespatialvariationinGHGemissionsinducedbymeteorologicalconditionsamongspecificlocations.Ingeneral,theresearchneededtodevelopamorecompleteunderstandingoftheGHGemissionscanbesummarizedas:

Developdatabasesfromresearchobservationsofcommercialfacilitiesthatcharacterizethestoragesystem,timeinstorage,environmentalconditionsandlocation,andtheattributesofthemanuresource,e.g.,typeofanimal,diet,loadingrate.

UtilizethedatabasestoderivesimulationmodelstoquantifytheGHGemissionsfromdifferentmanuremanagementsystems.

ValidatethemodelsusingindependentobservationsfrommanuremanagementsystemsdistributedaroundtheUnitedStates.

Developoperationalmodelscapableofbeingappliedtoproductionscalesystemswhichutilizesimpleparametersasinputvariablesandproduceresultsinagreementwiththemorecomplexsimulationmodels.

UtilizethesemodelstodeveloppotentialstrategieswhichcouldbeemployedtomitigateGHGemissionsfrommanuremanagementsystems.

TemporaryStackandLong‐TermStockpileMethaneemissiondatafromsolidstoragesindifferentregionsunderdifferentclimatesarelimited.InordertodevelopamoreaccuratemodeltoestimatetheCH4emissionfromsolidmanurestorages,in‐depthstudiesareneededtointegratetemperature,storagetime,storagemethod,andmassflowwithCH4emissionindifferentregions.AsforN2Oemission,systematicallycollectingmoreintensedata(avarietyofspatialandtemporalscales)fromdifferentregionswillbeagoodfirststeptowardaccurateN2Oemissionmodels.Oncethesedataarecollectedandusedtodevelop/validatemodels,workwilllikelybeneededtodevelopfarmer‐friendlymodelsusing


5-107

simplefarmparametersasinputvariables,resultinginemissionsestimatesthatarecorrelatedwiththoseofmorecomplexmodels.Forexample,thesemodels,ifsynchronized,couldformpartofacomprehensivemanurestewardshiptoolkit.

ThereisapaucityofdataonCH4andN2Oemissionsfromopenlot(beeffeedlotsanddairies)pensurfacesandrunoffcontrolstructuresandonthechemicalandphysicalfactorscontrollingthoseemissions.

CompostingGreenhousegasemissionsdatafromcompostingindifferentregionsunderdifferentoperationalconditionsarelimited.AgoodfirststeptowardanaccurateGHGemissionsmodelwouldbetocollectmoredatafromdifferentregionsanddifferentoperationalconditions.Consequently,in‐depthstudiesintegratingcompostpilesize/surfacearea,pileshape,aerationrate,storagetime,compostingtemperature,etc.,withGHGemissionsneedtobeconductedtodevelopcomplexmodelsdescribingGHGemissionsfromcomposting.Furthermore,workwilllikelybeneededtodevelopfarmer‐friendlymodelsusingsimplefarmparametersasinputvariables,resultinginemissionestimationsthatarecorrelatedwiththoseofmorecomplexmodels.

TherehavebeensomestudiesperformedtoestimatetheemissionfactorsforN2Ofromcompostingmanureindifferentsystemsandfordifferentlivestockcategories.(Fukummotoetal.,2003;Szantoetal.,2006)haveconductedstudiesoncompostingswinemanureatspecificambienttemperatures.Factorshavebeenpresentedinthestudiesbutthereissignificantuncertaintyduetothelimiteddataavailable.Furtherresearchisneededtorefinetheseemissionfactorsaswellasdevelopfactorsforotheranimals.

AerobicLagoonIn‐depthstudiesareneededtointegratelagoondepths,aerationrate,pH,temperature,andnutrientconditionsofmanurewithGHGemissions,whichwillfacilitatethedevelopmentofcomprehensivemodelstopredictGHGemissionsunderdifferentoperationalandclimateconditions.Simplifiedandfarm‐friendlymodelsusingfarmoperationalparametersasinputsshouldbedevelopedtohelpfarmsestimatetheGHGemissionsattheentitylevel.

AnaerobicLagoon,RunoffHoldingPond,andStorageTanksAllmodelstoestimateGHGemissionsfromliquidmanurestoragearerelativelyinaccurate,duetothecomplexityandvarietyoflivestockmanureoperations.Inordertodevelopamoreaccuratemodeltoestimateemissionsfromliquidmanurestorages,in‐depthstudiesareneededtointegratemanurestorageconfiguration,temperature,storagetime,storagemethod,massflow,andsurfaceturbulencewithemissionsindifferentregions.Inaddition,systematicallycollectingmoredatafromdifferentregionswillbeveryhelpfultodevelopmorestatisticallyaccuratemodelstoestimateGHGemissions.

AnaerobicDigestionChangesinchemicaloxygendemand,volatilesolids,totalsolids,andnitrogenintheanaerobicdigestionprocessareindirectlylinkedtoGHGemissionsfrompost‐treatmentofanaerobicdigestioneffluent.TheeffectivenessofanaerobicdigestionatmitigatingGHGemissionshasbeenstudiedintensively.However,anaerobicdigestioneffluentcanleadtoGHGemissions.Morein‐depthstudiesareneededtodevelopintegratedmodelsthatcanaccuratelypredicttheoverallGHGemissionfromthecombinationofanaerobicdigestionandpost‐treatmentapproaches.

CombinedAerobicTreatmentSystemsMethodsandtechniquestoreducethecapitalandoperatingcostsareneeded.Thereisalsoaneedtodevelopbetterwaystoconserveandderiveenergyfromthewastematerial.Thereisapaucityof


5-108

dataonGHGemissionsfromthesesystemsanddevelopmentofemissionmodelswillrequireintegrationofdatacharacterizingthesesystemsandtheclimaticconditionsinordertodevelopthesemodels.Thesemodelswillneedtobevalidatedagainstobserveddata.

NutrientRemovalVariousmethodsofnitrogenremoval,suchasbiologicalnitrogenremoval,Anamox,NH3stripping,ionexchange,andstruvitecrystallization,shouldbeinvestigatedatcommercial‐scaleanimaloperationsunderdifferentclimateconditions.Characteristicsofmanure,massflow,andgasemissionsshouldbecloselymonitoredinordertoprovidethedataneededtoconstructrelativelypreciseestimationmodels.Inaddition,furtherresearchisneededtopilotinnovativebeefanddairyGHGemissionreductionstrategiesinfeedlotsanddairies.

ConstructedWetlandAlthoughtherearenumerouspaperspublishedaboutvariousaspectsoftreatmentwetlandeffectivenessandemissions,therecurrentlyisnotanestablishedmethodforcalculationofGHGemissionsfromanyofthetreatmentwetlandtypes.Moreover,therearenotsufficientunifyingpublicationstosuggestthatareliablemethodcouldbeestablishedwithinthescopeofthisreport.AmorerobustandextensivedatabaseonGHGemissionsfromtreatmentwetlandsisneeded.Concomitantly,thereisaneedforbetterpredictiveequationandmodels.

Thermo‐ChemicalConversionMorestudiesareneededontheeffectsofthermalconversionofanimalmanureonGHGemissioninordertoconcludedetailedemissionprofilescorrespondingtodifferenttypeofmanure.ThesestudieswouldentaildetailedobservationsofthemanureconversionsystemalongwithGHGemissionsandinformationontheenvironmentalconditions.


5-109

Appendix5‐A:EntericCH4fromFeedlotCattle–MethaneConversionFactor(Ym)AsnotedintheBeefProductionSystemssection(Section5.3.2.2),amodifiedIPCC(2006)methodisproposedtoestimateentericCH4emissionsfromfinishingbeefcattle.Forthisreport,abaselinescenariobasedontypicalU.S.beefcattlefeedingconditionswasestablishedandbaselinevaluesweresetbasedonpublishedresearch.Toestimatemethaneemissions,emissionvaluesaremodifiedusingadjustmentfactorsthatarebasedonchangesinanimalmanagementandfeedingconditionsfromthebaselinescenario.Thisappendixpresentsbackgroundinformationonthebaselinescenarioandadjustmentfactors.

ThefollowingbaselinescenariosareestablishedforbeefcattleinU.S.feedlots:

1. Mediumtolargeframesteer(orheifer)yearlingsarefedahighconcentratefinishingdietcontaining<=10percentforageindietdrymatter(=to8to18percentNDF)indry‐lot,soil‐surfacedpens.

2. Thegrainportionofthedietisatleast70percentofdietdrymatter.3. Thegrainsourceissteamflaked(SFC)orhighmoisturecorn(HMC).4. Thedietarycrudeproteinconcentrationis12.5to13.5percentofdietdrymatter

(VasconcelosandGalyean,2007).5. Thedietaryruminallydegradableprotein(DIPorRDP)concentrationis7.5to9percentof

dietdrymatter(VasconcelosandGalyean,2007).6. Thedietcontainsmonensin(Rumensin,ElancoAnimalHealth)atrecommended

concentrations(VasconcelosandGalyean,2007).7. Dietsforheiferscontainmelengestrolacetate(MGA)attherecommendedconcentrations

(VasconcelosandGalyean,2007).8. Cattleareimplantedwithanestrogenicimplantthroughoutthefeedingperiod(Vasconcelos

andGalyean,2007).9. Nobeta‐agonistisfed.10. Thedietcontainsnosupplementalfat(vegetableoil,yellowgrease,etc.)andhasatotalfat

concentrationoflessthan4.5percentofdietdrymatter.11. EntericCH4emissionisthreepercentofgrossenergyintake(GEI:(IPCC,2006).12. Thedietaryforageischoppedalfalfa,sorghum,orgrasshayatsevento10percentofdiet

drymatter.13. Thedietcontainsmineralsandvitaminsattherecommendedlevel(NRC,2000).14. Temperaturesaremild/moderateduringthefeedingperiod.15. Cattleareslaughteredatanaveragebodyweightofapproximately582kg(1,280lb.)(KSU,

2012).16. Averagedressingpercentis61percent.17. Cattlearefed150days.

TheYmadjustmentfactorsforfeedlotcattlefedhigh‐concentratedietsinTable5‐11weredeterminedbasedonthefollowingliteraturereviewsandanalyses.

Ionophores:Onaverage,thefeedingofionophoresdecreasesDMIbyaboutfivepercent(Delfinoetal.,1988;Vogel,1995;RobinsonandOkine,2001;Tedeschietal.,2003)anddecreasesADGbyabouttwopercent(Delfinoetal.,1988;Tedeschietal.,2003).Feedingionophoresdecreasesentericmethaneemissionsapproximately20percentforthefirsttwotofourweeksonfeed(Tedeschietal.,2003;Guanetal.,2006).Therefore,overa150‐dayfeedingperiod,overallentericmethane


5-110

emissionsaredecreasedapproximately4percent.Becauseofanincreaseinthegain:feedratio,entericmethaneemissionsperunitofproductionaredecreasedwhenionophoresarefed.

SupplementalFat:Foreachonepercentincreaseinsupplementalfat(uptoamaximumoffourpercentaddedfat),entericmethaneemissions(asapercentageofgrossenergyintake)decreaseapproximately3.8to5.6percent(ZinnandShen,1996;Beaucheminetal.,2008;Martinetal.,2010).AconservativevalueoffourpercentperonepercentincreaseinsupplementalfatisrecommendedbecausemanyfatsourcesusedintheindustryarepartiallysaturatedandmayhavelesseffectonentericCH4productionthanthehighlyunsaturatedfatsusedinmoststudies.Forexampleifthreepercentsupplementalfatisaddedtothediet,thenCH4productionisdecreased12percent(threepercentaddedfattimesfourpercentisequivalenttoa12percentdecrease).TherevisedentericCH4emissionis2.64percentofGEI(threepercentbaseline*0.88=2.64percentofGEI).Manydistiller’sgrainscontainapproximately8to12percentfat.Additionofdistiller’sgrainmayserveasasourceofsupplementalfat,andthusdecreaseentericCH4(McGinnetal.,2009).HoweverHalesetal.(2013)notedthatfeedingincreasingconcentrationsofWetDistillersGrainswithSolubles(WDGS)inequal‐fatdietsincreasedentericCH4,likelyduetotheincreasedNDFintake.12

Grainprocessing&Grainsource:GrainprocessingdirectlyaffectsentericCH4productionviaitseffectsonruminalfermentation.EntericCH4emissions,asapercentofGEI,are20percentgreaterwithdietsbasedonDRCthanindietsbasedonsteam‐flakedcorn(SFC)orhighmoisturecorn(HMC)(Archibequeetal.,2006;Halesetal.,2012).Moreextensivegrainprocessingmayalsoimprovethegain:feedratioabout10percent(Owensetal.,1997;ZinnandBarajas,1997)andmay,decreasemanureCH4emissionsviadecreasedfecalstarchexcretion(ZinnandBarajas,1997;Halesetal.,2012).EntericCH4emissionsare20to40percentgreaterwithfinishingdietsbasedonbarleythandietsbasedoncorn;presumablybecauseofthelowerstarchandhigherfibercontentofbarley(Benchaaretal.,2001;BeaucheminandMcGinn,2005).Amean(30%)forthesestudiesisrecommendedforabarleyadjustmentfactor.

DietaryForageandGrainConcentrationeffects:LimiteddataexiststoevaluateeffectsofdietaryforageandgrainconcentrationonentericmethaneproductionfrombeefcattlethatarefedtypicalU.S‐based,highconcentratefinishingdiets.EquationsfromEllisetal.(2007;2009)illustratetheeffectsofdietaryforage,NDF,andstarchonentericCH4production.Inparticular,thefollowing10equationsillustratetherelationships:

CH4(MJ/day)=3.96+0.561×DMI(kg/day) CH4(MJ/day)=4.79+0.0492×Forage(%) CH4(MJ/day)=5.58+0.848×NDF(kg/day) CH4(MJ/day)=5.70+1.41×ADF(kg/day) CH4(MJ/day)=2.29+0.670×DMI(kg/day) CH4(MJ/day)=4.72+1.13×Starch(kg/day) CH4(MJ/day)=‐1.01+2.76×NDF(kg/day)+0.722×Starch(kg/day) CH4(MJ/day)=2.68–1.14(Starch:NDF)+0.786×DMI(kg/day) CH4(MJ/day)=2.50=0.367×Starch(kg/day)+0.766×DMI(kg/day) CH4(MJ/day)=2.70+(1.16×DMI(kg/day))–(15.8×etherextract(kg/day))

12Ymisadjustedfordistillergrainsbychangesinfatcontentandgrainconcentration.Forexample,a30percentconcentrationofdistillergrainsinthefinishingdietwilltypicallyincreasethedietaryfatlevelby2to3percentanddecreasethegraincontentby25to30percent.TheresultingchangeinYmisadecreaseby8percenttoaccountforincreaseinfatcontentandanincreaseof10percenttoaccountforadecreaseingraincontent(i.e.,Ym=3%x0.92x1.10=3.036%).


5-111

Todevelopadjustmentfactorsforgrainconcentrationsindiets,artificialdatasetswerecreatedthatvariedinforage(rangeof5to25percent),NDF(range10to20percent),fat(rangeof3to6percent),andstarch(rangeof30to60percentofdietdrymatter)content.Usingthesedatasets,entericCH4emissionswereestimatedusingtheappropriateequation(s)ofEllisetal.(2007;2009).EffectsofdietarychangesonentericCH4werethendeterminedbylinearregressionanalysis.Onaverage,entericCH4production(MJ/day)increasedfivepercentforeachonepercentincreaseindietaryforageconcentration;increased13percentforeachonekgincreaseindietaryNDFintake,increasedfivepercentforeachonekgincreaseinstarchintakeanddecreasedfivepercentforeachoneunitincreaseinthedietarystarch:NDFratio.SmallincreasesinforageconcentrationfromthebaselinevaluehadsmalleffectsonYm;whereas,greaterincreaseshadalargereffect(Halesetal.,2012;Halesetal.,2014).AnevaluationofthesefactorsindicatedanentericCH4Ymadjustmentfactorof10%forsmallincreasesinforage(anddecreasesingrainconcentration)andalargercorrectionfactorof40percentforgreaterchanges(dietconcentratelessthan45percent).Thesefactorsarerecommendedforaccountingforthegrainconcentrationinfinishingdiets.

NoYmadjustmentfactorwasexplicitlymodeledtoaccountforthefollowingdietarymanagementfactors:13

Beta‐agonists:Beta‐agonistsdonotdirectlyaffecttheYm(i.e.,entericCH4emissionsperunitofgrossenergyintake),thereforenoadjustmentfactorisrecommended.However,becauseofa4percentincreaseinfeedefficiency,a2.5to3.5%increaseinhotcarcassweight(HCW),andanincreaseinlivebodyweight(Vasconcelosetal.,2008;Elametal.,2009;Montgomeryetal.,2009;Delmoreetal.,2010;Radunz,2011),entericCH4emissionsperunitofproductionaredecreasedwhenbeta‐agonistsarefed.

Melengestrolacetate(MGA:heifersonly):FeedingMGAtoheifersdoesnotdirectlyaffectentericCH4emissions.However,becauseofaninepercentincreaseinthegain:feedratio(Hilletal.,1988;KreikemeierandMader,2004)entericCH4emissionsperunitofproductionaredecreasedwhenMGAisfed.

DirectFedMicrobials:MostdirectfedmicrobialsdonotappeartodirectlyaffectentericCH4emissionsandeffectsonanimalperformancearesomewhatvariable(Krehbieletal.,2003).Noadjustmentfactorisrecommendedforthefeedingofdirectfedmicrobials.

DietaryCrudeProteinandRuminalDegradableProtein(RDP):DietaryproteinmaypotentiallyaffectanimalperformanceandentericCH4emissionsviaeffectsonruminalfermentation.However,thereisnoreadilyavailabledatawithmodernfeedlotdietswithwhichtocompare(BergerandMerchen,1995;RobinsonandOkine,2001;Gleghornetal.,2004;Coleetal.,2006;Wagneretal.,2010).ThereisnorecommendedYmadjustmentfactorfordietaryprotein.Dietaryproteinmayaffectemissionsofmanuregreenhousegases(N2O)anddefinitelyaffectsNH3emissions(Toddetal.,2013).

Implantingregimens:ImplantsdonotdirectlyaffectentericCH4emissions.Howeverbecauseofanincreaseinfeedefficiency,livebodyweight,andHCW(Herschleretal.,1995;RobinsonandOkine,2001;Wilemanetal.,2009),entericCH4emissionsperunitofproductionaredecreasedwhenimplantsareused.

Ambienttemperature:ColdandhottemperaturesmaypotentiallyaffectentericCH4emissionduetoeffectsonfeedintake,ruminaldigestionandrateofpassage(Young,1981);however,theactualeffectsarenotclear.Thereforenoadjustmentfactorforenvironmentaltemperatureisused.ColdtemperaturesmaydecreaseCH4,N2OandNH3lossesfrompen

13AlthoughthesemanagementfactorsarenotmodeledtoimpactYm,someofthemdoimpactentericCH4perunitofproduction.Hence,inevaluatingmethaneintensityperunitofproduction,thesefactorswouldhaveanimpact.


5-112

surfacesviaeffectsonmicrobialactivityinthemanure.Conversely,warmtemperaturesmayincreaseemissionsfrommanureviaincreasedmicrobialactivity.

TheIPCCTier2modeliscurrentlythemostusefulforpredictingemissionsfromcow‐calfandstockerproduction,aswell,asnotedintheearliercow‐calfandstockerSections(5.3.2.2).EntericemissionsfromallcattleotherthandairycowsanddairyheifersareestimatedusingtheIPCCTier2equationorthemodifiedIPCCTier2previouslydiscussedforfeedlotcattle.Tousetheseequations,itisnecessarytomakesuretheinputstotheequationsareasaccurateaspossible.ForDE(asapercentageofGE),werecommendusingthefeedstuffscompositiontableprovidedinNRC(1989)andEwan(1989).SeveralfeedstuffsfromthetableareincludedinTable5‐C‐1.Afterreviewofthemodels,theirstrengthsandlimitations,modelsbasedontheMillsequations(e.g.,DairyGEM,COWPOLL,IFSM)appeartobethemostusefulforpredictingemissionsfromdairycattle.TheMits3equationrecommendedforcalculatingentericCH4emissionsfromdairycowsanddairyheifers(usedinDairyGEM/IFSM)requiresdifferentdietaryinputinformationthanthatrequiredfortheIPCCTierIIequation.Specifically,DairyGEM/IFSMrequiresthestarchandADFcontentoffeeds.BecausestarchisnearlyequivalenttoNFC(whichisstarch+sugar+pectin)inhighforagediets(dairydiets),weuseNFCintheMits3equation(NFC=100–(NDF+CP+EE+Ash)).ThesevaluescanbefoundinAppendix5‐B.


5-113

Appendix5‐B:FeedstuffsCompositionTableThistableprovideddatainputsforentericfermentationemissionscalculationsforcattleandsheep.

Table5‐B‐1:FeedstuffsCompositionTable(Preston2013,exceptwherenotedfordigestibleenergy)

Feedstuff DM %

Energy Protein Fiber

EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Alfalfa Cubes x91 57 57 25 57 18 30 29 36 46 40 2.0 11 1.30 0.23 1.9 0.37 0.33 20

Alfalfa Dehydrated

17% CP 92 61 62 31 61 65.16 19 60 26 34 45 6 3.0 11 1.42 0.25 2.5 0.45 0.28 21

Alfalfa Fresh 24 61 62 31 61 62.54

b 19 18 27 34 46 41 3.0 9 1.35 0.27 2.6 0.40 0.29 18

Alfalfa Hay Early Bloom

90 59 59 28 59 63.72 19 20 28 35 45 92 2.5 8 1.41 0.26 2.5 0.38 0.28 22

Alfalfa Hay Midbloom

89 58 58 26 58 61.79 17 23 30 36 47 92 2.3 9 1.40 0.24 2.0 0.38 0.27 24

Alfalfa Hay Full Bloom

88 54 54 20 54 55.71 16 25 34 40 52 92 2.0 8 1.20 0.23 1.7 0.37 0.25 23

Alfalfa Hay Mature

88 50 50 12 49 54.18 13 30 38 45 59 92 1.3 8 1.18 0.19 1.5 0.35 0.21 23

Alfalfa Seed Screenings

91 84 92 61 87 34 13 15 10.7 6 0.30 0.67

Alfalfa Silage 30 55 55 21 55 60.71

c 18 19 28 37 49 82 3.0 9 1.40 0.29 2.6 0.41 0.29 26

Alfalfa Silage Wilted

39 58 58 26 58 60.71

d 18 22 28 37 49 82 3.0 9 1.40 0.29 2.6 0.41 0.29 26

Alfalfa Leaf Meal

89 60 60 30 60 26 15 16 24 34 35 3.0 10 2.88 0.34 2.2 0.32 39

Alfalfa Stems 89 47 47 7 46 11 44 44 51 68 100 1.3 6 0.90 0.18 2.5

Almond Hulls 89 56 56 23 56 59.90 3 60 16 29 36 100 3.1 7 0.24 0.10 2.0 0.03 0.07 20

Ammonium Chloride

99 0 0 0 0 163 0 0 0 0 0 0.0 0.00 0.00 0.0 66.00 0.00 0

Ammonium Sulfate

99 0 0 0 0 132 0 0 0 0 0 0.0 24.15

Apples 17 70 73 44 71 3 10 7 9 25 10 2.2 2 0.06 0.60 0.8

Apple Pomace Wet

20 68 70 41 69 5 10 18 27 36 27 5.2 3 0.13 0.12 0.5 0.04 11

Apple Pomace Dried

89 67 69 40 68 56.69 5 15 18 28 38 29 5.2 3 0.13 0.12 0.5 0.04 11

Artichoke Tops (Jerusalem)

27 61 62 31 61 6 18 30 41 40 1.1 10 1.62 0.11 1.4

Avocado Seed Meal

91 52 52 16 51 20 19 24 1.2 16

Bahiagrass Hay 90 53 53 18 53 54.85 6 37 32 41 72 98 1.8 7 0.47 0.20 1.4 0.21

Bakery Product Dried

90 90 100 68 94 81.31 11 30 3 9 30 0 11.5 4 0.16 0.27 0.4 2.25 0.15 33

Bananas 24 84 92 61 87 4 4 5 0.8 3 0.03 0.11 1.5 8

Barley Hay 90 57 57 25 57 60.89 9 28 37 65 98 2.1 8 0.30 0.28 1.6 0.19 25

Barley Silage 35 59 58 26 58 12 22 34 37 58 61 3.0 9 0.46 0.30 2.4 0.22 28

Barley Silage Mature

35 58 58 26 58 12 25 30 34 50 61 3.5 9 0.30 0.20 1.5 0.15 25

Barley Straw 90 44 44 1 43 43.98 4 70 42 55 78 100 1.9 7 0.32 0.08 2.2 0.67 0.16 7

Barley Grain 89 84 92 61 87 12 28 5 7 20 34 2.1 3 0.06 0.38 0.6 0.18 0.16 23

Barley Grain, Steam Flaked

85 90 100 70 100 12 39 5 7 20 30 2.1 3 0.06 0.35 0.6 0.18 0.16 23


5-114

Feedstuff DM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Barley Grain Steam Rolled

86 84 92 61 87 12 38 5 7 20 27 2.1 3 0.06 0.41 0.6 0.18 0.17 30

Barley Grain 2-row

87 84 92 61 87 12 6 8 24 34 2.3 2 0.05 0.31 0.6 0.18 0.17

Barley Grain 6-row

87 84 92 61 87 11 6 8 24 34 2.2 3 0.05 0.36 0.6 0.18 0.15

Barley Grain Lt. Wt. (42-44

lb/bu) 88 78 83 54 80 13 30 9 12 30 34 2.3 4

Barley Feed Pearl Byproduct

90 74 78 49 76 15 25 12 15 3.9 5 0.05 0.45 0.7 0.06

Barley Bran 91 59 59 28 59 12 28 21 27 36 6 4.3 7

Barley Grain Screenings

89 71 74 46 73 12 9 11 2.6 4 0.35 0.33 0.9 0.15

Beans Navy Cull

90 84 92 61 87 84.52 24 25 5 8 20 0 1.4 5 0.15 0.60 1.4 0.06 0.26 45

Beet Pulp Wet 17 77 82 53 79 75.09 9 35 20 25 45 30 0.7 5 0.65 0.08 0.9 0.40 0.22 21

Beet Pulp Dried 91 76 81 52 78 79.81 9 44 21 26 46 33 0.7 5 0.65 0.08 0.9 0.40 0.22 21

Beet Pulp Wet with Molasses

24 77 82 53 79 11 25 16 21 39 33 0.6 6 0.60 0.10 1.8 0.42 11

Beet Pulp Dried with Molasses

92 77 82 53 79 82.52 11 34 17 23 40 33 0.6 6 0.60 0.10 1.8 0.42 11

Beet Root (Sugar)

23 80 86 56 83 4 5 7 16 0.4 3

Beet Tops (Sugar)

19 58 58 26 58 14 11 14 25 41 1.3 24 1.10 0.22 5.2 0.20 0.45 20

Beet Top Silage 25 52 52 16 51 12 12 2.0 32 1.38 0.22 5.7 0.57 20

Bermudagrass Coastal

Dehydrated 90 62 63 33 63 16 40 26 29 40 10 3.8 7 0.40 0.25 1.8 0.72 0.23 18

Bermudagrass Coastal Hay

89 56 56 23 56 53.05 10 20 30 36 73 98 2.1 6 0.47 0.21 1.5 0.70 0.22 16

Bermudagrass Hay

89 53 53 18 53 50.79 10 18 29 37 72 98 1.9 8 0.46 0.20 1.5 0.70 0.25 31

Bermudagrass Silage

26 50 50 12 49 10 15 28 35 71 48 1.9 8 0.46 0.20 1.5 0.72 0.25 31

Birdsfoot Trefoil Fresh

22 66 68 38 67 21 20 21 31 47 41 4.4 9 1.78 0.25 2.6 0.25 31

Birdsfoot Trefoil Hay

89 57 57 25 57 16 22 31 38 50 92 2.2 8 1.73 0.24 1.8 0.25 28

Biuret 99 0 0 0 0 248 0 0 0 0 0 0.0 0 0.00 0.00 0.0 0.00 0.00 0

Blood Meal, Swine/Poultry

91 66 68 38 67 92 82 1 2 10 0 1.4 3 0.32 0.28 0.2 0.30 0.70 22

Bluegrass KY Fresh Early

Bloom 36 69 71 43 70 75.62 15 20 27 32 60 41 3.9 7 0.37 0.30 1.9 0.42 0.19 25

Bluegrass Straw 93 45 45 3 44 6 40 50 78 90 1.1 6 0.20 0.10

Bluestem Fresh Mature

61 50 50 12 49 56.82 6 34 2.5 5 0.40 0.12 0.8 0.05 28

Bread Byproduct

68 90 100 68 94 14 24 1 2 3 0 3.0 3 0.10 0.18 0.2 0.76 0.15 40

Brewers Grains Wet

23 85 93 62 88 62.66 26 52 13 21 45 18 7.5 4 0.30 0.58 0.1 0.15 0.32 78

Brewers Grains Dried

92 84 92 61 87 60.43 25 54 14 24 49 18 7.5 4 0.30 0.58 0.1 0.15 0.32 78

Brewers Yeast Dried

94 79 85 55 81 48 3 1.0 7 0.10 1.56 1.8 0.41 41

Bromegrass Fresh Immature

30 64 65 36 65 78.57 15 22 28 33 54 40 4.1 10 0.45 0.34 2.3 0.21 20


5-115

FeedstuffDM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

%NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Bromegrass Hay

89 55 55 21 55 62.19

e 10 33 35 41 66 98 2.3 9 0.40 0.23 1.9 0.40 0.19 19

Bromegrass Haylage

35 57 57 25 57 11 26 36 44 69 61 2.5 8 0.38 0.30 2.0 0.20 19

Buckwheat Grain

88 75 79 50 77 72.27 12 13 17 2.8 2 0.11 0.36 0.5 0.05 0.16 10

Buttermilk Dried 92 88 98 65 91 34 0 5 0 0 0 5.0 10 1.44 1.00 0.9 0.09 44

Cactus, Prickly Pear

23 61 62 31 62 5 16 20 28 2.1 18 4.00 0.10 1.5 0.20

Calcium Carbonate

99 0 0 0 0 0 0 0 0 0 0.0 99 38.50 0.04 0.1 0.00 0

Canarygrass Hay

91 53 53 18 53 9 26 32 34 67 98 2.7 8 0.38 0.25 2.7 0.14 18

Canola Meal, Solv. Ext.

90 72 75 47 74 41 30 11 19 29 23 2.0 8 0.74 1.14 1.1 0.07 0.78 68

Carrot Pulp 14 62 63 33 63 6 19 23 40 0 7.8 9

Carrot Root Fresh

12 83 90 60 86 92.29 10 9 11 20 0 1.4 10 0.55 0.32 2.5 0.50 0.17

Carrot Tops 16 73 77 48 75 13 18 23 45 41 3.8 15 1.94 0.19 1.9

Cattle Manure Dried

92 38 40 0 36 30.58 15 35 42 55 0 2.5 14 1.15 1.20 0.6 1.78 240

Cheatgrass Fresh Immature

21 68 70 41 69 16 23 2.7 10 0.60 0.28

Citrus Pulp Dried

90 78 83 54 80 7 38 13 20 21 33 2.9 7 1.81 0.12 0.8 0.04 0.08 14

Clover Ladino Fresh

19 69 71 43 70 73.22 25 20 14 33 35 41 4.8 11 1.27 0.38 2.4 0.20 20

Clover Ladino Hay

90 61 62 31 61 63.40 21 25 22 32 36 92 2.0 9 1.35 0.32 2.4 0.30 0.20 17

Clover Red Fresh

24 64 65 36 65 18 21 24 33 44 41 4.0 9 1.70 0.30 2.0 0.60 0.17 23

Clover Red Hay 88 55 55 21 55 58.33 15 28 30 39 51 92 2.5 8 1.50 0.25 1.7 0.32 0.17 17

Clover Sweet Hay

91 53 53 18 53 16 30 30 38 50 92 2.4 9 1.27 0.25 1.8 0.37 0.46

Coconut Meal, Mech. Ext.

92 76 81 52 78 79.66 21 56 13 21 56 23 6.8 7 0.40 0.30 1.0 0.33 0.04

Coffee Grounds 88 20 36 0 16 13 41 68 77 10 15.0 2 0.10 0.08

Corn Whole Plant Pelleted

91 63 64 34 64 9 45 21 24 40 6 2.4 6 0.50 0.24 0.9 0.14

Corn Fodder 80 65 66 37 66 9 45 25 29 48 100 2.4 7 0.50 0.25 0.9 0.20 0.14

Corn Stover Mature (Stalks)

80 54 54 20 54 5 30 35 43 70 100 1.3 7 0.45 0.15 1.2 0.30 0.14 22

Corn Silage, Milk Stage

26 65 66 37 66 8 18 26 32 54 60 2.8 6 0.40 0.27 1.6 0.11 20

Corn Silage, Mature Well

Eared 34 72 75 47 74 72.88 8 28 21 27 46 70 3.1 5 0.28 0.23 1.1 0.20 0.13 22

Corn Silage, Sweet Corn

24 65 66 37 66 11 20 32 57 60 5.0 5 0.24 0.26 1.2 0.17 0.16 39

Corn Grain, Whole

88 88 98 65 91 88.85 9 58 2 3 9 60 4.3 2 0.02 0.30 0.4 0.05 0.14 18

Corn Grain, Rolled

88 88 98 65 91 9 54 2 3 9 34 4.3 2 0.02 0.30 0.4 0.05 0.14 18

Corn Grain, Steam Flaked

85 93 104 71 97 95.44 9 59 2 3 9 40 4.1 2 0.02 0.27 0.4 0.05 0.14 18

Corn Grain, High Moisture

74 93 104 71 97 91.64 10 42 2 3 9 0 4.0 2 0.02 0.30 0.4 0.06 0.14 20

Corn Grain, High Oil

88 91 102 69 95 8 54 2 3 8 60 6.9 2 0.01 0.30 0.3 0.05 0.13 18


5-116

Feedstuff DM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Corn Grain, Hi-Lysine

92 87 96 64 90 12 58 4 4 11 60 4.4 2 0.03 0.24 0.4 0.05 0.11 18

Corn and Cob Meal

87 82 89 59 85 83.15 9 52 9 11 26 56 3.7 2 0.06 0.27 0.5 0.05 0.13 16

Corn Cobs 90 48 48 9 47 53.18 3 70 36 39 88 56 0.6 2 0.12 0.04 0.8 0.27 5

Corn Screenings

86 91 102 69 95 10 52 3 4 9 20 4.3 2 0.04 0.27 0.4 0.05 0.12 16

Corn Bran 91 76 81 52 78 11 10 17 51 0 6.3 3 0.04 0.15 0.1 0.13 0.08 18

Corn Germ, Full-fat

97 135 198 160 198 12 55 6 11 36 20 44.9 2 0.02 0.28 0.1 0.02 0.17 60

Corn Gluten Feed

90 80 86 56 83 78.47 22 25 9 12 38 36 3.2 7 0.11 0.84 1.3 0.25 0.47 84

Corn Gluten Meal 41% CP

91 85 93 62 88 46 63 5 9 32 23 3.2 3 0.13 0.55 0.2 0.07 0.62 35

Corn Gluten Meal 60% CP

91 89 99 67 93 75.29 67 65 3 6 11 23 2.5 2 0.06 0.54 0.2 0.10 0.90 40

Corn Cannery Waste

29 68 70 41 69 8 15 28 36 59 0 3.0 5 0.10 0.29 1.0 0.13 25

Cottonseed, Whole

91 95 107 73 99 23 38 27 37 47 100 19.4 5 0.16 0.64 1.0 0.06 0.24 34

Cottonseed, Whole, Delinted

90 95 107 73 99 24 39 19 28 40 100 22.9 5 0.12 0.54 1.2 0.24 36

Cottonseed, Whole,

Extruded 92 87 98 67 91 26 50 32 44 53 33 9.5 5 0.17 0.68 1.3 0.24 38

Cotton Gin Trash (Burrs)

91 42 43 0 40 9 35 50 70 100 2.0 14 1.40 0.18 1.9 0.14 25

Cottonseed Hulls

90 45 45 3 44 44.30 5 45 48 70 87 100 1.8 3 0.15 0.08 1.0 0.02 0.05 10

Cottonseed Meal, Solv. Ext.

41% CP 90 77 82 53 79 72.85 47 42 13 18 25 23 1.5 7 0.22 1.23 1.6 0.05 0.44 66

Cottonseed Meal, Mech. Ext. 41% CP

92 79 85 55 81 71.71 46 50 13 19 31 23 5.0 7 0.21 1.18 1.6 0.05 0.42 64

Crab Waste Meal

91 29 37 0 30 32 65 11 13 3.0 43 15.00 1.88 0.5 1.63 0.27 107

Crambe Meal, Solv. Ext.

91 81 88 58 84 31 45 25 35 47 23 1.4 8 1.27 0.86 1.1 0.70 1.26 44

Crambe Meal, Mech. Ext.

92 88 98 65 91 28 50 24 33 42 25 17.0 7 1.22 0.78 1.0 0.65 1.18 41

Cranberry Pulp Meal

88 49 49 11 48 7 26 47 54 33 15.7 2

Crawfish Waste Meal

94 25 36 0 29 35 74 12 15 42 13.10 0.85

Curacao Phosphate

99 0 0 0 0 0 0 0 0 0 0.0 95 34.00 15.00

Defluorinated Phosphate

99 0 0 0 0 0 0 0 0 0 0.0 95 32.60 18.07 1.0 100

Diammonium Phosphate

98 0 0 0 0 115 0 0 0 0 0 0.0 35 0.52 20.41 0.0 2.16

Dicalcium Phosphate

96 0 0 0 0 0 0 0 0 0 0.0 94 22.00 18.65 0.1 1.00 70

Distillers Grains, Wet

25 91 102 69 95 28 52 8 18 40 4 9.6 5 0.10 0.70 1.0 0.20 0.60 95

Distillers Grain, Barley

90 75 79 50 77 30 56 16 20 44 4 8.5 4 0.15 0.67 1.0 0.18 0.43 50

Distillers Grain, Corn, Dry

91 95 106 72 99 76.86 30 58 8 16 44 4 9.5 4 0.09 0.75 0.9 0.14 0.70 65


5-117

Feedstuff DM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Distillers Grain, Corn, Wet

36 97 109 74 102 30 47 8 16 44 4 9.5 4 0.09 0.75 0.9 0.14 0.70 65

Distillers Grain, Corn with Solubles

89 98 111 76 103 81.50 30 54 8 16 38 4 11.9 6 0.20 0.75 0.9 0.18 0.80 85

Distillers Dried Solubles

93 87 96 64 91 79.45 31 47 4 7 22 4 13.0 8 0.35 1.20 1.8 0.28 1.10 91

Distillers Corn Stillage

7 92 103 70 96 22 55 8 10 21 0 8.1 5 0.14 0.72 0.2 0.60 60

Distillers Grain, Sorghum, Dry

91 84 92 61 87 72.85 33 62 13 20 44 4 10.0 4 0.20 0.68 0.3 0.50 50

Distillers Grain, Sorghum, Wet

35 86 95 63 89 33 55 13 19 43 4 10.0 4 0.20 0.68 0.3 0.50 50

Distillers Grain, Sorghum with

Solubles 92 85 93 62 88 33 53 12 18 42 4 10.0 4 0.23 0.70 0.5 0.70 55

Elephant (Napier) Grass Hay, Chopped

92 55 55 21 54 9 24 46 63 85 2.0 10 0.35 0.30 1.3 0.10

Fat, Animal, Poultry,

Vegetable 99 195 285 230 285

80.08f

0 0 0 0 0 99.0 0 0.00 0.00 0.0

Feather Meal Hydrolyzed

93 67 69 40 68 87 68 1 14 42 23 7.0 3 0.48 0.45 0.1 0.20 1.82 90

Fescue KY 31 Fresh

29 64 65 36 65 15 20 25 32 64 40 5.5 9 0.48 0.37 2.5 0.18 22

Fescue KY 31 Hay Early

Bloom 88 60 60 30 60 53.57 18 22 25 31 64 98 6.6 8 0.48 0.36 2.6 0.27 24

Fescue KY 31 Hay Mature

88 52 52 16 51 11 30 30 42 73 98 5.0 6 0.45 0.26 1.7 0.14 22

Fescue (Red) Straw

94 43 44 0 41 4 41 1.1 6 0.00 0.06

Fish Meal 90 74 78 49 76 66 60 1 2 12 10 9.0 20 5.55 3.15 0.7 0.76 0.80 130

Flax Seed Hulls 91 38 40 0 36 9 32 39 50 98 1.5 10

Garbage Municipal Cooked

23 80 86 56 83 16 9 50 59 30 20.0 10 1.20 0.43 0.6 0.67

Glycerol (Glycerin)

88 90 100 68 94 0 0 0 0 0 0 0.0 6 4.00

Grain Screenings

90 65 66 37 66 14 14 5.5 9 0.25 0.34 30

Grain Dust 92 73 77 48 75 10 11 2.2 10 0.30 0.18 42

Grape Pomace Stemless

91 40 42 0 38 27.50 12 45 32 46 54 34 7.6 9 0.55 0.07 0.6 0.01 24

Grass Hay 88 58 58 26 58 10 30 33 41 63 98 3.0 6 0.60 0.21 2.0 0.20 28

Grass Silage 30 61 62 31 61 11 24 32 39 60 61 3.4 8 0.70 0.24 2.1 0.22 29

Guar Meal 90 72 75 47 74 39 34 16 3.9 5

Hominy Feed 90 89 99 67 93 11 48 5 8 21 9 6.5 3 0.04 0.55 0.6 0.06 0.10 32

Hop Leaves 37 49 49 11 48 15 15 3.6 35 2.80 0.64

Hop Vine Silage 30 53 53 18 53 15 21 24 3.1 20 3.30 0.37 1.8 0.22 44

Hops Spent 89 35 39 0 33 23 26 30 4.6 7 1.60 0.60

Kelp Dried 91 32 38 0 29 54.67 7 7 10 0.5 39 2.72 0.31

Kenaf Hay 92 48 48 9 47 10 31 44 56 98 2.9 12

Kochia Fresh 29 55 55 21 55 65.11 16 23 1.2 18 1.10 0.30

Kochia Hay 90 53 53 18 53 14 27 1.7 14 1.00 0.20

Kudzu Hay 90 54 54 20 54 16 33 2.6 7 3.00 0.23


5-118

FeedstuffDM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

%NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Lespedeza Fresh Early

Bloom 25 60 60 30 60 16 50 32 2.0 10 1.20 0.24 1.1 0.21

Lespedeza Hay 92 54 54 20 54 14 60 30 3.0 7 1.10 0.22 1.0 0.19 29

Limestone Ground

98 0 0 0 0 0 0 0 0 0 0 0.0 98 34.00 0.02 0.03

Limestone Dolomitic Ground

99 0 0 0 0 0 0 0 0 0 0 0.0 98 22.30 0.04 0.4

Linseed Meal, Solv. Ext.

91 77 82 53 79 38 36 10 18 25 23 1.7 6 0.43 0.91 1.5 0.04 0.47 60

Linseed Meal, Mech. Ext.

91 82 89 59 85 37 40 10 17 24 23 6.0 6 0.42 0.90 1.4 0.04 0.46 59

Meadow Hay 90 50 50 12 49 63.37 7 23 33 44 70 98 2.5 9 0.61 0.18 1.6 0.17 24

Meat Meal, Swine/Poultry

93 71 74 46 73 56 64 2 7 48 0 10.5 24 9.00 4.42 0.5 1.27 0.48 190

Meat and Bone Meal,

Swine/Poultry 93 72 75 47 74 56 24 1 5 34 0 10.0 29 13.50 6.50

Milk, Dry, Skim 94 87 96 64 90 36 0 0 0 0 0 0.9 8 1.36 1.09 1.7 0.96 0.34 41

Mint Slug Silage 27 55 55 21 55 14 24 1.8 16 1.10 0.57

Molasses Beet 77 75 79 50 77 91.95 8 0 0 0 0 0 0.2 12 0.14 0.03 6.0 1.64 0.60 18

Molasses Cane 77 74 78 49 76 86.63 6 0 0 0 0 0 0.5 14 0.95 0.09 4.2 2.30 0.68 15

Molasses Cane Dried

94 74 78 49 76 82.12 9 0 2 3 7 0 0.3 14 1.10 0.15 3.6 3.00 30

Molasses, Cond.

Fermentation Solubles

43 69 71 43 70 16 0 0 0 0 0 1.0 26 2.12 0.14 7.5 2.73 0.93 30

Molasses Citrus 65 75 79 50 77 84.11 9 0 0 0 0 0 0.3 8 1.84 0.15 0.2 0.11 0.23 137

Molasses Wood,

Hemicellulose 61 70 73 44 71 1 0 1 2 4 0 0.6 7 1.10 0.10 0.1 0.05

Monoammonium Phosphate

98 0 0 0 0 70 0 0 0 0 0 0.0 24 0.30 24.70 0.0 1.42 81

Mono-Dicalcium Phosphate

97 0 0 0 0 0 0 0 0 0 0.0 94 16.70 21.10 0.1 1.20 70

Oat Hay 90 54 54 20 54 59.36 10 25 31 39 63 98 2.3 8 0.40 0.27 1.6 0.42 0.21 28

Oat Silage 35 60 60 30 60 64.00

g 12 21 31 39 59 61 3.2 10 0.34 0.30 2.4 0.50 0.25 27

Oat Straw 91 48 48 9 47 49.64 4 40 41 48 73 98 2.3 8 0.24 0.07 2.5 0.78 0.22 6

Oat Grain 89 76 81 52 78 75.63 13 18 11 15 28 34 5.0 4 0.05 0.41 0.5 0.11 0.20 40

Oat Grain, Steam Flaked

84 88 98 65 91 13 26 11 15 30 32 4.9 4 0.05 0.37 0.5 0.11 0.20 40

Oat Groats 91 91 102 69 95 88.29 18 15 3 6.6 2 0.08 0.47 0.4 0.10 0.20

Oat Middlings 90 91 102 69 95 16 20 4 6 6.0 3 0.07 0.48 0.5 0.23

Oat Mill Byproduct

89 33 38 0 30 7 27 37 2.4 6 0.13 0.22 0.6 0.24

Oat Hulls 93 38 40 0 36 38.39 4 25 33 41 75 90 1.6 7 0.16 0.15 0.6 0.08 0.14 31

Orange Pulp Dried

89 79 85 55 81 9 9 16 20 33 1.8 4 0.71 0.11 0.6 0.05

Orchardgrass Fresh Early

Bloom 24 65 66 37 66 60.13 14 23 30 32 54 41 4.0 9 0.33 0.39 2.7 0.08 0.20 21

Orchardgrass Hay

88 59 59 28 59 64.29

h 10 27 34 40 67 98 3.3 8 0.32 0.30 2.6 0.41 0.20 26

Pea Vine Hay 89 59 59 28 59 11 32 50 62 92 2.0 7 1.25 0.24 1.3 0.20 20


5-119

FeedstuffDM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

%NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Pea Vine Silage 25 58 58 26 58 16 29 44 55 61 3.3 8 1.25 0.28 1.6 0.29 32

Pea Vine Straw 89 51 51 14 50 49.62 7 41 49 72 98 1.4 7 0.75 0.13 1.1 0.15

Peas Cull 88 85 93 62 88 23 22 7 9 12 0 1.4 4 0.14 0.46 1.1 0.06 0.26 30

Peanut Hulls 91 22 36 0 18 23.17 7 63 65 74 98 1.5 5 0.20 0.07 0.9

Peanut Meal, Solv. Ext.

91 77 82 53 79 71.90 51 27 9 16 27 23 2.5 6 0.26 0.62 1.1 0.03 0.30 38

Peanut Skins 92 0 0 0 0 17 13 20 28 0 22.0 3 0.19 0.20

Pearl Millet Grain

87 82 89 59 85 68.04 13 2 6 18 34 4.5 3 0.03 0.36 0.5

Pineapple Greenchop

17 47 47 7 46 8 24 35 64 41 2.4 7 0.28 0.08

Pineapple Bran 89 71 74 46 73 72.43 5 20 33 66 20 1.5 3 0.26 0.12

Pineapple Presscake

21 71 74 46 73 5 24 35 69 20 0.8 3 0.25 0.09

Potato Vine Silage

15 59 59 28 59 15 26 3.7 19 2.10 0.29 4.0 0.37

Potatoes Cull 21 80 86 56 83 10 0 2 3 4 0 0.4 5 0.03 0.24 2.2 0.30 0.09

Potato Waste Wet

14 82 89 59 85 7 0 9 11 18 0 1.5 3 0.16 0.25 1.2 0.36 0.11 12

Potato Waste Dried

89 85 93 62 88 95.85 8 0 7 9 15 0 0.5 5 0.16 0.25 1.2 0.39 0.11 12

Potato Waste Wet with Lime

17 80 86 56 83 5 0 10 12 16 0 0.3 9 4.20 0.18

Potato Waste Filter Cake

14 77 82 53 79 5 0 2 7.7 3 0.10 0.19 0.2

Poultry Byproduct Meal

93 79 85 55 81 62 49 2 14.5 17 4.00 2.25 0.5 0.58 0.56 129

Poultry Manure Dried

89 38 40 0 36 67.83 28 22 13 15 35 0 2.1 33 10.20 2.80 2.3 1.05 0.20 520

Prairie Hay 91 50 50 12 49 55.53 7 37 34 47 67 98 2.0 8 0.40 0.15 1.1 0.06 0.06 34

Pumpkins, Cull 11 80 86 56 83 15 14 21 30 0 8.9 9 0.24 0.43 3.3

Rice Straw 91 40 42 0 38 51.16 4 38 47 72 100 1.4 13 0.23 0.08 1.2 0.11

Rice Straw Ammoniated

87 45 45 3 44 9 39 53 68 100 1.3 12 0.25 0.08 1.1 0.11

Rice Grain 89 79 85 55 81 83.86 8 30 10 12 16 34 1.9 5 0.07 0.32 0.4 0.09 0.05 17

Rice Polishings 90 90 100 68 94 14 4 5 14.0 9 0.05 1.34 1.2 0.12 0.19 28

Rice Bran 91 71 74 46 73 66.64 14 30 13 18 24 0 16.0 11 0.07 1.70 1.8 0.09 0.19 40

Rice Hulls 92 13 35 0 8 15.91 3 45 44 70 81 90 0.9 20 0.12 0.07 0.5 0.08 0.08 24

Rice Mill Byproduct

91 39 41 0 37 7 32 50 60 0 5.7 19 0.25 0.48 2.2 0.30 31

Rye Grass Hay 90 58 58 26 58 66.07

i 10 30 33 38 65 98 3.3 8 0.45 0.30 2.2 0.18 27

Rye Grass Silage

32 59 59 28 59 14 25 22 37 59 61 3.3 8 0.43 0.38 2.9 0.73 0.23 29

Rye Straw 89 44 44 1 43 33.72 4 44 55 71 100 1.5 6 0.24 0.09 1.0 0.24 0.11

Rye Grain 89 80 86 56 83 84.83 14 20 3 9 19 34 2.5 3 0.07 0.55 0.5 0.03 0.17 33

Safflower Meal, Solv. Ext.

91 56 56 23 56 57.72 24 33 41 57 36 1.3 6 0.35 0.79 0.9 0.21 0.23 65

Safflower Meal Dehulled, Solv.

Ext. 91 75 79 50 77 70.55 47 11 20 27 30 0.8 7 0.38 1.50 1.2 0.18 0.22 36

Safflower Hulls 91 14 35 0 34 4 58 73 90 100 3.7 2

Sagebrush Fresh

50 50 50 12 49 59.04

j 13 25 30 38 9.2 10 1.00 0.25 0.22

Sanfoin Hay 88 61 62 31 62 14 60 24 3.1 9


5-120

Feedstuff DM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Shrimp Waste Meal

90 48 48 9 47 50 60 11 5.5 25 8.50 1.75 1.15

Sodium Tripolyphosphat

e 96 0 0 0 0 0 0 0 0 0 0.0 96 0.00 25.98 0.0 0.00

Sorghum Stover 87 54 54 20 54 5 33 41 65 100 1.8 10 0.50 0.12 1.2

Sorghum Silage 32 59 59 28 59 65.58 9 25 27 38 59 70 2.7 6 0.48 0.21 1.7 0.45 0.11 30

Sorghum Grain (Milo), Ground

89 82 89 59 85 11 55 3 6 15 5 3.1 2 0.04 0.32 0.4 0.10 0.14 18

Sorghum Grain (Milo), Flaked

82 90 100 68 94 11 62 3 6 15 38 3.1 2 0.04 0.28 0.4 0.10 0.14 18

Soybean Hay 89 52 52 16 51 54.10 16 33 40 55 92 3.5 8 1.28 0.29 1.0 0.15 0.24 24

Soybean Straw 88 42 43 0 40 45.98 5 44 54 70 100 1.4 6 1.59 0.06 0.6 0.26

Soybeans Whole

88 92 103 70 96 41 28 8 11 15 100 18.8 5 0.27 0.64 1.9 0.03 0.34 56

Soybeans Whole,

Extruded 88 93 104 71 97 40 35 9 11 15 100 18.8 5 0.27 0.64 2.0 0.03 0.34 56

Soybeans Whole, Roasted

88 93 104 71 97 40 48 9 11 15 100 18.8 5 0.27 0.64 2.0 0.03 0.34 56

Soybean Hulls 90 77 82 52 79 66.86 13 28 39 48 62 28 2.3 5 0.60 0.19 1.3 0.02 0.12 38

Soybean Meal, Solv. Ext. 44%

CP 89 84 92 61 87 79.50 49 35 7 10 15 23 1.5 7 0.36 0.70 2.2 0.07 0.41 62

Soybean Meal, Solv. Ext. 49%

CP 89 87 96 64 90 54 36 4 6 8 23 1.3 7 0.28 0.71 2.2 0.08 0.45 61

Soybean Mill Feed

90 50 50 12 49 15 36 46 1.9 6 0.46 0.19 1.7 0.07

Spelt Grain 88 75 79 50 77 77.18 13 27 10 17 21 34 2.1 4 0.04 0.40 0.4 0.15 47

Sudangrass Fresh Immature

18 70 73 44 71 73.27 17 23 29 55 41 3.9 9 0.46 0.36 2.0 0.11 24

Sudangrass Hay

88 57 57 25 57 62.67 9 30 36 43 67 98 1.8 10 0.50 0.22 2.2 0.80 0.12 26

Sudangrass Silage

31 58 58 26 58 60.29 10 28 30 42 64 61 3.1 10 0.58 0.27 2.4 0.52 0.14 29

Sunflower Meal, Solv. Ext.

92 65 66 37 66 44.89 40 27 18 22 36 23 2.8 8 0.44 0.97 1.1 0.15 0.33 55

Sunflower Meal with Hulls

91 57 57 25 57 31 35 27 32 44 37 2.4 7 0.40 1.03 1.0 0.30 85

Sunflower Seed Hulls

90 40 42 0 38 4 65 52 63 73 90 2.2 3 0.00 0.11 0.2 0.19 200

Sugar Cane Bagasse

91 39 41 0 37 52.15 1 49 60 86 100 0.6 4 0.90 0.29 0.5 0.10

Tapioca Meal, Cassava

Byproduct 89 82 89 59 85 1 5 8 34 0.8 3 0.03 0.05

Timothy Fresh Pre-Bloom

26 64 65 36 65 11 20 31 36 59 41 3.8 7 0.40 0.28 1.9 0.57 0.15 28

Timothy Hay Early Bloom

88 59 59 28 59 60.75 11 22 32 39 63 98 2.7 6 0.58 0.26 1.9 0.51 0.21 30

Timothy Hay Full Bloom

88 57 57 25 57 58.68 8 30 34 40 65 98 2.6 5 0.43 0.20 1.8 0.62 0.13 25

Timothy Silage 34 59 59 28 59 59.32 10 25 34 45 70 61 3.4 7 0.50 0.27 1.7 0.15

Tomatoes 6 69 71 43 70 16 9 11 4.0 6 0.14 0.35 4.2

Tomato Pomace Dried

92 64 65 36 65 53.98 23 26 50 55 34 10.6 6 0.43 0.59 3.6

Triticale Hay 90 56 56 23 56 10 34 41 69 98 0.30 0.26 2.3 25


5-121

Feedstuff DM %


EE%

ASH%

Ca %

P %

K %

Cl%

S %

Zn ppmTDN

% NEm NEg NEl

(Mcal/cwt.)

DE (% of

GE)a

CP%

UIP%

CF%

ADF%

NDF%

eNDF%

Triticale Silage 34 58 58 26 58 14 30 39 56 61 3.6 0.58 0.34 2.7 0.28 36

Triticale Grain 89 85 93 62 88 83.82 14 25 4 5 22 34 2.4 2 0.07 0.39 0.5 0.17 37

Turnip Tops (Purple)

18 68 70 41 69 18 10 13 2.6 14 3.10 0.40 3.0 1.80 0.27

Turnip Roots 9 86 95 63 89 92.94 12 0 11 34 44 40 1.6 9 0.65 0.31 3.1 0.65 0.43 40

Urea 46% N 99 0 0 0 0 288 0 0 0 0 0 0.0 0 0.00 0.00 0.0 0.00 0.00 0

Vetch Hay 89 58 58 26 58 59.44 18 14 30 33 48 92 1.8 8 1.25 0.34 2.4 0.13

Wheat Fresh, Pasture

21 71 74 46 73 76.07 20 16 18 30 50 41 4.0 13 0.35 0.36 3.1 0.67 0.22

Wheat Hay 90 57 57 25 57 62.73 9 25 29 38 66 98 2.0 8 0.21 0.22 1.4 0.50 0.19 23

Wheat Silage 33 59 59 28 59 63.99 12 21 28 37 62 61 3.2 8 0.40 0.28 2.1 0.50 0.21 27

Wheat Straw 91 43 44 0 41 45.77 3 60 43 57 81 98 1.8 8 0.17 0.06 1.3 0.32 0.17 6

Wheat Straw Ammoniated

85 50 50 12 49 9 25 40 55 76 98 1.5 9 0.15 0.05 1.3 0.30 0.16 6

Wheat Grain 89 88 98 65 91 86.45

k 14 23 3 4 12 0 2.3 2 0.05 0.43 0.4 0.09 0.15 40

Wheat Grain Hard

89 88 98 65 91 88.54

l 14 28 3 6 14 0 2.0 2 0.05 0.43 0.5 0.16 45

Wheat Grain Soft

89 88 98 65 91 89.96

m 12 23 3 4 12 0 2.0 2 0.06 0.40 0.4 0.15 30

Wheat Grain, Steam Flaked

85 91 102 69 95 14 29 3 4 12 0 2.3 2 0.05 0.39 0.4 0.15 40

Wheat Grain Sprouted

86 88 98 65 91 12 18 3 4 13 0 2.0 2 0.04 0.36 0.4 0.17 45

Wheat Bran 89 70 73 44 71 71.16 17 28 11 14 46 4 4.4 7 0.13 1.32 1.4 0.05 0.24 96

Wheat Middlings

89 80 86 56 83 18 22 8 11 36 2 4.7 5 0.14 1.00 1.3 0.05 0.20 98

Wheat Mill Run 90 76 81 52 78 79.11 17 28 9 12 37 0 4.5 6 0.11 1.10 1.2 0.07 0.22 90

Wheat Shorts 89 78 83 54 80 19 25 8 10 30 0 5.3 5 0.10 0.93 1.1 0.08 0.20 118

Wheatgrass Crested Fresh Early Bloom

37 60 60 30 60 79.78 11 25 26 28 50 41 1.6 7 0.46 0.32 2.4

Wheatgrass Crested Fresh

Full Bloom 50 55 55 21 55 65.89 10 33 33 36 65 41 1.6 7 0.39 0.28 2.1

Wheatgrass Crested Hay

92 54 54 20 54 56.51 10 33 33 36 65 98 2.4 7 0.33 0.20 2.0 32

Whey Dried 94 82 89 59 85 91.47

n 14 15 0 0 0 0 0.9 10 0.98 0.88 1.3 1.20 0.92 10

Yeast, Brewer's 92 79 85 55 81 73.76 47 30 3 4 0 0.9 7 0.13 1.49 1.8

DM =Drymatter ADF = AciddetergentfiberTDN =Totaldigestiblenutrients NDF = NeutraldetergentfiberNEm =Netenergyformaintenance eNDF = effectiveneutraldetergentfiberNEg =Netenergyforgrowth EE = EtherextractNEl =Netenergyforlactation ASH =AshMcal =Megacalories Ca =Calciumcwt =Centumweight(hundredweight) P =PhosphorousDE =Digestibleenergy K = PotassiumGE =Grossenergy Cl =ChlorineCP =Crudeprotein S =SulfurUIP =Undegradableintakeprotein Zn =ZincCF =Crudefiber ppm =partspermillionaDE(%ofGE)valuesfromEwan(1989)bAverageoffresh,latevegetative;fresh,earlybloom;fresh,midbloom;fresh,fullbloomcAverageofsilagewilted–earlybloom;silagewilted–midbloom;silagewilted–fullbloomdAverageofsilagewilted–earlybloom;silagewilted–midbloom;silagewilted–fullbloom


5-122

eAverageofhay–sun‐cured,latevegetative;hay–sun‐cured,latebloomfAverageoffat,animalpoultry;oil,vegetablegAverageofsilage,latevegetative;silage,doughstagehAverageofhay,sun‐cured,earlybloom;hay,sun‐cured,latebloomiAverageofryegrass,ItalianLoliummultiflorum:hay,sun‐cured,latevegetative;hay,sun‐cured,earlybloom;averageofryegrass,perennialLoliumperenne:hay,sun‐curedjAverageofsagebrush,bigArtemisiatridentate:browse,fresh,stem‐cured;sagebrush,budArtemisiaspinescens:browse,fresh,earlyvegetative;browse,fresh,latevegetative;andsagebrush,fringedArtemisiafrigida:browse,fresh,midbloom;browse,fresh,maturekAverageofwheat,DurumTriticumdurumandwheatTriticumaestivumgrainlAverageofgrain,hardredspring;grain,hardwintermAverageofgrain,softredwinter;grain,softwhitewinter;grain,softwhitewinter,pacificcoastnAverageofdehydrated(cattle)andlowlactose,lowlactose,dehydrated(driedwheyproduct)(cattle)


5-123

Appendix5‐C:EstimationMethodsforAmmoniaEmissionsfromManureManagementSystemsThisappendixpresentsmethodsforestimatingNH3frommanuremanagementsystems.NH3,althoughnotaGHG,isemittedinlargequantitiesfromanimalhousingandmanuremanagementsystemsandisanindirectprecursortonitrousoxide(N2O)emissionsaswellasanenvironmentalconcern.

5‐C.1 MethodforEstimatingAmmoniaEmissionsUsingEquationsfromIntegratedFarmSystemModel

Ammoniaemissionsfrommanurestoragearemainlyfromtotalammoniacalnitrogen(TAN).Formanyanimalconfinementsystems,ithasbeenreportedthatmostoftheureainmanurehasbeenconvertedtoTANandlostasNH3bythetimemanureistransferredtostorage(Rotzetal.,2011b);therefore,onlyorganicnitrogeninthemanureatthestoragestage,whichismineralizedtoTAN,isusedtoestimateNH3release.TherearefourmainstepsrelatedtoNH3releasetotheatmosphere:diffusion,dissociation,aqueoustogaspartitioning,andmasstransportawayfromthemanuresurface(Rotzetal.,2011b).Forsolidmanure,diffusionthroughthemanureisamainconstrainttotheemissionrate.Forliquidmanure,NH3emissionsareafunctionoftheoverallmasstransferrateandthedifferenceintheNH3concentrationbetweenthelagoonandthesurroundingatmosphere.

5‐C.1.1 RationaleforSelectedMethod

Ammoniaemissionsfromtemporarystackandlongtermstockpiles,aerobiclagoons,anaerobiclagoons,runoffholdingponds,andstoragetankscanbecalculatedusingequationsfromtheDairyGEMModel(asubsetoftheIntegratedFarmSystemModel)(Rotzetal.,2011b).TheequationsfromRotzetal.aretheonlyavailablemethodsforestimatingNH3emissionsfromthesesystemsandbestdescribesthequantitativerelationshipamongstactivitydataattheentitylevel.

5‐C.1.2 ActivityData

InordertoestimatethedailyNH3emissionfromtemporarystack,long‐termstockpiles,anaerobiclagoons,runoffholdingponds,andstoragetanks,thefollowinginformationisneeded:

Totalnitrogencontentofmanure ManuretotalNH3‐Ncontent Surfaceareaofmanurepile Temperatures(localambienttemperatureandmanuretemperature) Localambientairvelocity Foraerobiclagoons,thepHofthelagoonisalsoneeded.

Thetimingofmeasurementscanbebasedondietarychangesorseasonaltimeframe,whichisdecidedbyindividualfarmentity.However,duetothedynamicnatureofmanurepilescausingthe

Ammonia

Methodisafunctionofthesurfaceareaofthestorageunit,resistancetomasstransfer,ambientairvelocity,totalNH3andorganicnitrogencontent,rateoforganicnitrogentransformationtototalammoniacalnitrogen,andmanuretemperatureasdefinedbyRotzetal.(2011b).

Ammoniaandorganicnitrogencontentcanbeobtainedfromsamplingandlabtesting.


5-124

changesofthevariables,frequentmeasurementsofmanurecharacteristicsarerecommendedtoensureaccuracyoftheestimation.

5‐C.1.3 AncillaryData

TheancillarydatausedtoestimateNH3emissionfortemporarystoragearekinematicviscosityofair,massdiffusivityofNH3,andresistancetomasstransfer.ThekinematicviscosityofairatstandardatmosphericpressureislistedinTable5‐C‐1.ThemassdiffusivityofNH3isobtainedfromreferences(PaulandWatson,1966;Baker,1969)andlistedinTable5‐C‐2.TheresistancetomasstransferfordifferentsolidmanurestoragesareobtainedfromtheDairyGEMmodel(Rotzetal.,2011a).

5‐C.2 MethodforAmmoniaEmissionsfromTemporaryStack,Long‐TermStockpile,AnaerobicLagoons/RunoffHoldingPonds/StorageTanks,andAerobicLagoons

TemporaryStack,Long‐TermStockpile,andAnaerobicLagoons/RunoffHoldingPonds/StorageTanksAsindicatedinEquation5‐C‐1,NH3emissionsareafunctionoftheoverallmasstransferrateandthedifferenceinNH3concentrationbetweenthemanureandsurroundingatmosphere.ThemeanambientairNH3concentrationis1.3µg/m3basedonpassivemeasurementsfrom35locationsacross24StatesintheU.S.withoneyearormoreofmeasurements(AmmoniaMonitoringNetwork,NationalAtmosphericDepositionProgram).TheHenry’sLawconstantisusedtodefinetheratioofNH3concentrationinasolutioninequilibriumwithgaseousNH3concentrationinairandisexponentiallyrelatedtotemperature.

aAmmoniaconcentrationinambientaircanbeobtainedfromNationalAtmosphericDepositionProgram(nadp.sws.uiuc.edu/amon/).bShapefactors( )arelistedinAppendix5‐D.

Equation5‐C‐2describesthecalculationforHenry’sLawConstant.Themanuretemperatureiscalculatedastheaverageambienttemperatureovertheprevious10days.

Equation5‐C‐1:AmmoniaEmissionsfromTemporaryStack,LongTermStockpiles,andAnaerobicLagoons/RunoffHoldingPonds/StorageTanks

Where:

ENH3 =NH3emissionsperday(kgNH3day‐1)

24 =Hoursperday(hrday‐1)

3,600 =Secondsperhour(shr‐1)

Asurface =Footprintofmanurestorage(m2)×shapefactorb

K =Overallmasstransfercoefficient(ms‐1)asdefinedinEquation5‐C‐3

TANm =Totalammoniacalnitrogeninthemanure(kgm‐3)

TANa =NH3concentrationinambientaira(kgm‐3)

H =Henry’sLawconstantasdefinedinEquation5‐C‐2


5-125

Theoverallmasstransfercoefficientisexpressedasthereciprocaloftheoveralleffectiveresistanceofthemanure.ThemasstransfercoefficientthroughgaseousphaseonthetopofmanureiscalculatedusingEquation5‐C‐3.TheresistancetomasstransferiscalculatedinEquation5‐C‐5.IthasbeenreportedthatthemasstransfercoefficientthroughmanurehasrelativelylittleeffectonthemasstransferofNH3(Ni,1999)andthusthe1/Klisconsiderednegligibleinthefollowingequation.

Themasstransfercoefficientthroughgaseousphase(Equation5‐C‐4)isestimatedfromtheairfrictionvelocityandSchmidtnumberofair.TheTurbulentSchmidtnumberisdependentonthecharacteristicsofthegasandthescalesofatmosphericturbulence.Sinceturbulenceishighlydependentonmanycomplexinteractions,theTurbulentSchmidtnumberwasapproximatedbyonlyaccountingforthegascharacteristics.ThesecharacteristicsareexpressedinthemolecularSchmidtnumber,definedasSC=ν/D,whereνisthekinematicviscosityofair(m2s‐1),andDisthemassdiffusivityofNH3(m2s‐1).InordertocalculateSchmidtnumber,thedynamicviscosityofair,thedensityoftheair,andthemassdiffusivityofNH3aregivenbasedonairtemperatureinTable5‐C‐1andTable5‐C‐2.

Equation5‐C‐2:CalculationHenry’sLawConstant

..

Where:

H=Henry’sLawconstantforNH3(aqueoustogas)

T=Manuretemperature(Kelvindegree)

Equation5‐C‐3:OverallMassTransferCoefficient

Where:

K =Overallmasstransfercoefficient(ms‐1)

H =Henry’sLawconstantforNH3(aqueoustogas)

Rm =Resistancetomasstransfer(sm‐1)

Kg =Masstransfercoefficientthroughgaseousphaseonthetopofmanure(ms‐1)

Kl =Masstransfercoefficientthroughmanure(ms‐1)


5-126

ThemasstransfercoefficientthroughmanurehaslittleeffectonthemasstransferofNH3,soitisnegligible.Theresistancetomasstransferisthesumoftheresistancethroughthemanureandtheresistanceofcovermaterialsoverthemanure(Equation5‐C‐5).ThevaluesforresistancetomasstransferthroughthemanureandresistancetomasstransferthroughthecoverarelistedinTable5‐C‐3fortemporarystackandlong‐termstockpileandinTable5‐C‐4foranaerobiclagoons,runoffholdingponds,andstoragetanks.

Table5‐C‐3:ResistancetoMassTransferforSolidManureStorageTypeofManureStorage Rs(sm‐1) Rc(sm‐1)

Uncoveredsolidmanure(drymatter>15%) 3×105 0Coveredsolidmanure(drymatter>15%) 3×105 2×105Uncoveredslurrymanure(drymater,10‐15%) 2×105 0

Table5‐C‐1:KinematicViscosityofAiratDifferentTemperatureatStandard

AtmosphericPressure

Temperature(°C)KinematicViscosity

(m2/s)x10‐5‐40 1.04‐20 1.170 1.325 1.3610 1.4115 1.4720 1.5125 1.5630 1.6040 1.6650 1.76

Source:White(1999).

Table5‐C‐2:Mass DiffusivityofAmmoniaatStandardAtmosphericPressure

Temperature(°C)DiffusivityofAmmonia

(m2/s)x10‐4‐40 0.1060 0.11030 0.20040 0.20950 0.233

Source:PaulandWatson (1966)andBaker(1969).

Equation5‐C‐4:CalculatingMassTransferCoefficientthroughGaseousPhase

. . . . .

Where:

Kg=Masstransfercoefficientthroughgaseousphaseonthetopofmanure(ms‐1)

Va=Ambientairvelocity(ms‐1)thatcanbeobtainedfromNationalWeatherServicebysearchingthetargetlocation

SC=TurbulentSchmidtnumberofNH3intheairabovemanuresurface(dimensionless)

Equation5‐C‐5:CalculationofResistancetoMassTransfer

Where:

Rm=Resistancetomasstransfer(sm‐1)

Rs=Resistancetomasstransferthroughthemanure(sm‐1)

Rc=Resistancetomasstransferthroughthecover(sm‐1)


5-127

TypeofManureStorage Rs(sm‐1) Rc(sm‐1)Coveredslurrymanure(drymater,10‐15%) 2×105 2×105

Source:Rotzetal.(2011b).Table5‐C‐4:ResistancetoMassTransferForAnaerobicLagoons,RunoffHoldingPonds,andStorageTanks

TypeofCover Rs(sm‐1) Rc(sm‐1)Uncoveredliquidmanure 0 0

Coveredliquidmanure 0 2×105Source:Rotzetal.(2011a).

AerobicLagoonsThemethodforestimatingNH3emissionsfromaerobiclagoons(Equation5‐C‐6)issimilartothatforstockpilesandanaerobiclagoonsbutaccountsfortheconcentrationofNH3intheliquid.

TheoverallmasstransfercoefficientiscalculatedusingEquation5‐C‐3withresistancetomasstransferassumedtobezero.Henry’sLawConstantiscalculatedusingEquation5‐C‐2andthemasstransfercoefficientthroughagaseousphaseiscalculatedusingEquation5‐C‐4.ThemasstransferthroughtheliquidfilmlayeriscalculatedusingEquation5‐C‐7.

Equation5‐C‐8describestheestimationmethodforNH3concentrationintheliquid.TheNH3fractionofTANinthelagoonliquidisafunctionofpHandadissociationconstantaccordingtoEquation5‐C‐9.

Equation5‐C‐6:ResistancetoMassTransferforSolidManureStorage(Rotzetal.,2011b)

Where:

ENH3 =NH3emissionsperday(kgday‐1)

24 =Hoursperday(hrday‐1)

3,600=Secondsperhour(sh‐1)

K =Overallmasstransfercoefficient(ms‐1)

Asurface=Surfaceareaoflagoon(m2)

NH3 =Concentrationintheliquid(kgm‐3)

Equation5‐C‐7:CalculatingtheMassTransferCoefficientthroughtheLiquidFilmLayer

Kl 1.417 10‐12 T4

Where:

Kl=Masstransfercoefficientthroughtheliquidfilmlayer(ms‐1)

T=Manuretemperature(Kelvin)


5-128

5‐C.3 MethodforEstimatingAmmoniaEmissionsfromCompostingUsingIPCCTier2Equations

Compostingisthecontrolledaerobicdecompositionoforganicmaterialintoastable,humus‐likeproduct(USDANRCS,2007).Eghballetal.(1997)reportedthat19to45percentofthenitrogenpresentinmanurewaslostduringcomposting,withthemajorityofthispresumablyasNH3.

5‐C.3.1 RationaleforSelectedMethod

TheIPCCmethodisadaptedforestimatingNH3emissionsandincorporatesNH3emissionfactorsfromastudyofcompostingcattleandswinemanure(HellebrandandKalk,2000).TheIPCCequationistheonlyavailablemethodforestimatingNH3emissionsfromcomposting.Thismethodologybestdescribesthequantitativerelationshipamongstactivitydataattheentitylevel.

Equation5‐C‐8:CalculatingtheAmmoniaConcentrationintheLiquid

Where:

NH3 =Concentrationintheliquid(kgm‐3)

F =NH3ofTANinthelagoonliquid

TAN =Totalammonianitrogeninthemanureliquid(kgm‐3)

Equation5‐C‐9:CalculatingtheAmmoniaFractionofTANintheLagoonLiquid

Where:

F =NH3ofTANinthelagoonliquid

pH =Hydrogenionconcentration

Ka =Dissociationconstant,whereK 10 .

T =Temperature(Kelvin)

Ammonia

IPCCTier2approachadjustedtoestimateNH3emissionsutilizingdataonanNH3emissionfactor,totalinitialnitrogen,anddrymanure.

TheNH3emissionfactorisobtainedfromastudyofcompostingmixtureofcattleandswinemanurebyHellebrandandKalk(2000).

Nitrogencontentcanbeobtainedfromsamplingandlabtesting. Methodistheonlyreadilyavailablemethod.


5-129

5‐C.3.2 ActivityData

InordertoestimatethedailyNH3emissions,thefollowinginformationisneeded:

Totaldrymanureinthestorage Totalnitrogeninmanure

Thetimingofmeasurementscanbebasedondietarychangesoronaseasonaltimeframe,whichisdecidedbyindividualfarmentity.However,duetothedynamicnatureofmanurestoragecausingchangesinthevariables,frequentmeasurementsofmanurecharacteristics(e.g.,volatilesolids,temperature,totaldrymanure)arerecommendedtoimproveaccuracyoftheestimation.

5‐C.3.3 AncillaryData

TheancillarydatausedtoestimateNH3emissionformanurecompostingisNH3emissionfactor(HellebrandandKalk,2000).

5‐C.4 MethodforAmmoniaEmissionsfromComposting

Ammoniaemissionsfromcompostingaredependentonvolatilizationandmineralizationafternitrification,decompositionoforganicnitrogencompounds,orureahydrolysis.AnIPCCTier2approachforestimatingN2OemissionsisadaptedtoestimateNH3emissionsfromcompostingofsolidmanure.TheNH3emissionfactorof0.05isobtainedfromastudyofcompostingmixtureofcattleandswinemanure(HellebrandandKalk,2000).Equation5‐C‐10providestheequationsforestimatingNH3emissions.

5‐C.5 UncertaintyinAmmoniaEmissionsEstimates

EstimationmethodsfromRotzetal.(2011b)areusedtoestimateNH3emissionsfromtemporarystackandlong‐termstockpilesandaerobiclagoons.Rotzetal.takesintoaccounttheamountofemissivesurfaceareaofthepileorlagoon.Giventhedifficultyofmeasuringthesurfaceareaofamanurepile,shapefactorshavebeendevelopedtoapproximatesurfaceareabasedongeneralshapeandfootprint.Theseshapefactorsprovideanestimatetotalsurfaceareaonly;thereisassociateduncertaintybasedontheaccurracyofthefootprintmeasurementsandhowwelltheshapeofthepilematchestheshapefactorsdefined.

TheRotzetal.equationsrequiretheNH3concentrationintheambientaironsite.NationaldataonambientNH3concentrationsareavailablefromtheNationalAtmosphericDepositionProgram.The

Equation5‐C‐10:IPCCTier2ApproachforCalculatingNH3 EmissionsfromCompostingofSolidManure

Where:

ENH3 =NH3emissionsperday(kgNH3day‐1)

m =Totaldrymanure(kgday‐1)

EFNH3 =NH3emission(loss)relativetototalnitrogeninmanure(kgNH3‐N(kgTN)‐1;=0.05)

TN =Totalnitrogenintheinitial(fresh)manure(kgTN(kgdrymanure)‐1)

=ConversionofNH3tonitrogen


5-130

ProgramprovidesambientNH3concentrationsfromapproximately60activemonitoringsitesacrossthecountry.Giventhedearthofmonitoringsitesandthepotentiallylongdistancesbetweentheentityandthenearestmeasurement,therecanbealargeamountofuncertaintyassociatedwiththeambientairNH3concentrationsusedforestimatingNH3emissions.

Table5‐C‐5:AvailableUncertaintyDataforAmmoniaEmissionsEstimates

ParameterAbbreviation/Sym

bol

DataInputUnit

EstimatedValue


(%

)


(%)

EffectiveLowerLimit

EffectiveUpperLimit

DataSource

pH pH ‐ 7.5 6.5 8.5 ExpertAssessment

Totalammonianitrogeninthemanure–beefearthenlot

TAN kgNH3/m3 0.1 0 0.02 ASABE(2005)

Totalammonianitrogeninthemanure–poultry,leghornpullets

TAN kgNH3/m3 0.85 0.66 1.04 ASABE(2005)

Totalammonianitrogeninthemanure–poultry,leghornhen

TAN kgNH3/m3 0.88 0.54 1.22 ASABE(2005)

Totalammonianitrogeninthemanure–poultry,broiler

TAN kgNH3/m3 0.75 ASABE(2005)

Ammoniaconcentrationintheliquid–dairylagooneffluent

NH3 kgNH3/m3 0.08 ASABE(2005)

Ammoniaconcentrationintheliquid–dairyslurry(liquid)


Ammoniaconcentrationintheliquid–SwineFinisher‐Slurrywet‐dryfeeders


Ammoniaconcentrationintheliquid–SwineSlurrystorage‐dryfeeders

NH3 kgNH3/m3 0.34 0.19 0.49 ASABE(2005)

Ammoniaconcentrationintheliquid–Swineflushbuilding


Ammoniaconcentrationintheliquid–Swineagitatedsolidsandwater


Ammoniaconcentrationintheliquid–SwineLagoonsurfacewater


Ammoniaconcentrationintheliquid–SwineLagoonsludge


Composting–Ammoniaemission(loss)relativetototalnitrogeninmanure

EFNH3 kgNH3‐N/kgN 0.05 HellebrandandKalk(2000)


5-131

Appendix5‐D:ManureManagementSystemsShapeFactors( )Factorscanbeappliedtoaccountforthedifferencesinemissivesurfaceareasfordifferentshapesofmanurepiles.Theequationsprovidedbelowprovideestimatesforthesurfaceareaforcommonpileshapes;theseestimatesareappliedforcalculatingNH3emissionsfromtemporarystacks.

Figure5‐D‐1:EquationsforCalculatingtheShapeFactorfora2‐SidedStorageBinwithQuarter‐ConePile


5-132

Figure5‐D‐2:EquationsforCalculatingtheShapeFactorfora3‐SidedStorageBin

Figure5‐D‐3:EquationsforCalculatingtheShapeFactorforaConicalManurePile


5-133

Figure5‐D‐4:EquationsforCalculatingtheShapeFactorforaFree‐Standing,TruncatedConicalStack

Figure5‐D‐5:EquationsforCalculatingtheShapeFactorforaWindrowwithTriangularCrossSection


5-134

Appendix5‐E:ModelReview:ReviewofEntericFermentationModelsAnumberofempiricalandmechanisticmodelshavebeendevelopedtoestimateentericCH4

production(Table5‐E‐1).TwoofthefactorsthataffectentericCH4productiontothegreatestextentaredietcompositionandlevelofintake.PredictionequationsandmodelsconstructedtopredictentericCH4aregenerallybasedonthesefactors.MoststatisticalequationsdevelopedtoestimateentericCH4emissionshavebeendevelopedusingdatasetsofanimalsfedhigh‐foragedietsormixeddiets;fewstudieshavefedhigh‐concentratedietstypicaloftoday’sU.S.feedlots.

Table5‐E‐1:ModelsPotentiallyUsefulinEstimatingEntericCH4EmissionsfromTypicalU.S.RuminantAnimals

Reference Variablemodeled Inputs/CommentsEmpiricalModels

IPCC(2006) EntericCH4No.ofanimals,animalspecies,animaltype,emissionfactorforeachanimaltype(Tier2CH4conversionfactor;Ym)

Kriss(1930) EntericCH4 Drymatterintake(DMI)Axelsson(1949) EntericCH4 DMIBratzler&Forbes(1940)

EntericCH4 Digestedcarbohydrate

Millsetal.(2003) EntericCH4Metabolizableenergy(ME)intake,starchandaciddetergentfiber(ADF)intake

Blaxter&Clapperton(1965)

EntericCH4Digestibleenergy(DE)(%)atmaintenanceintake,grossenergyintake(GEI),feedinglevel(multipleofmaintenance)

Moe&Tyrrell(1979) EntericCH4Digestiblesolublecarbohydrates,digestiblehemicellulose,digestiblecellulose

Holter&Young(1992) EntericCH4Digestiblesolublecarbohydrates,cellulose,hemicellulose,fatintake

Yanetal.(2009) EntericCH4Digestibleenergy,silage,andtotalDMI,silage,anddietADF

Ellisetal.(2007) EntericCH4 Metabolizableenergyintake,ADF,ligninintake

Ellisetal.(2009) EntericCH4Metabolizableenergyintake,cellulose,hemicellulose,andfatintake;non‐fibercarbohydrate,neutraldetergentfiber(NDF),andDMI

Millsetal.(2001) EntericCH4 DMIHolos(Littleetal.,2008)

EntericCH4,manureCH4

BasedonIPCC(2006)

CNCPS(2010)

EntericCH4,DMI,nutrientexcretion,urinenitrogenexcretion;

UsesequationofMillsetal.(2003)fordairyandEllisetal.(2007)forbeef.Animalcharacteristics,dietnutrientcomposition,feedproteinfractions,animalperformance,animalmanagement,insitudegradabilityoffeeds

IntegratedFarmSystemModel(Rotzetal.,2011b)

EntericCH4,nutrientexcretion,urinenitrogen,DMI,manureNH3,CH4,andN2O

UsestheMits3equationofMillsetal.(2003)forentericCH4,IPCC(2006)formanureCH4,andeitherDAYCENT(Chianeseetal.,2009d)orIPCC(2006)formanureN2O

Phetteplaceetal.(2001)

EntericCH4,manureCH4

Animalclass,animalageandbodyweight,quantityofmeat/mileproduced,feedtype,feedintake,manuremanagement

Process‐basedModels


5-135

Reference Variablemodeled Inputs/Comments

Kebreabetal.,(2004;2009)

EntericCH4,nutrientexcretion

DMI,NDF,degradableNDF,totalstarch,degradablestarch,solublesugarsindiet,dietnitrogen,NHx‐Nindiet,indigestibleprotein,rateofdegradationofstarch,andprotein

COWPOLL(Dijkstraetal.,1992;Millsetal.,2003;Banninketal.,2006;Kebreabetal.,2008)

EntericCH4

DMI,NDF,degradableNDF,totalstarch,degradablestarch,solublesugarsindiet,dietnitrogen,NHx‐Nindiet,indigestibleprotein,rateofdegradationofstarch,andprotein

MOLLY(Baldwin,1995)

EntericCH4 SimilartoCOWPOLL

Predictionmodelsforentericemissions.Thefollowingisabriefsummaryofthemodelsevaluatedandtheirstrengthsandlimitations.

SimpleRegressionModelBasedonDigestibleEnergy.BlaxterandClapperton(1965)developedasimpleregressionequationtoestimateentericCH4basedondigestibleenergy,feedintakeasapercentageofmaintenanceandGEI.Thedatasetusedtocreatethisempiricalmodelwascomposedmostlyofdatafromsheepfedlow‐concentratedietsinrespirationchambers,whichmayaccountforitslimitedaccuracyinpredictingCH4emissionsacrossruminantdiets(Johnsonetal.,1991).

EmpiricalModel.MoeandTyrrell(1979)developedanempiricalmodeltoestimateentericCH4emissionfromdairycowsbasedondietcomposition.Thisempiricalmodelwasdevelopedwithhigh‐foragedietsindairycowsfedinrespirationchambers;itsuseforestimatingbeefcattleentericemissionsisthereforelimited.

RegressionModel.Yanetal.(2000)developedregressionequationstopredictentericCH4emissionsfrombeefanddairycattlefeddietsbasedongrasssilage.Concentratesrepresentedfrom0to81.5percentoftheDMI,withameanof46.7percentofdietDMI.Whencorrectedtoequalfeedintakes,animalbodyweighthadnoeffectonentericCH4emissions.(Yanetal.,2000)validatedtheirequationsusingdatafromtheliterature,mostlydairystudieswithalldietsbasedongrasssilage.

RegressionEquations.Ellisetal.(2009)developedregressionequationstoestimateentericCH4productionfrombeefcattlebasedonstudiesinwhichcattlewerefedhigh‐concentrateormoderate‐concentrate(50percent)diets.Theseequationswerecomparedwith14equationsdevelopedearlierbyEllisetal.(2007),sevendevelopedbyMillsetal.(2003),theBlaxterandClapperton(1965)equation,andtheMoeandTyrrell(1979)equation.ThemeanentericCH4production(MJday‐1andpercentofGEI)inall12ofthestudieswasgreaterthanvaluesnotedmorerecently(Halesetal.,2012),possiblybecauseofdifferencesindietarygraincontentandfatsupplementation.However,someoftheEllis(2007;2009)equationsestimatedCH4emissionssimilartothosereportedbyToddetal.(2014a;2014b)inopenlotfeedlots.

Thelinearmodelwiththelowestresidualmeansquarepredictionerror(RMSPE)wasEquation5‐E‐1asfollows:


5-136

Apossibleadvantagetousingthisequation,comparedwithotherempiricalequations,isthatthevariablesrequiredforthecalculationscanbereadilyobtainedwithsometraininginnutrition.Anotheristhattheindependentvariablesinthemodel(energy,fiber,andfatintake)aretheprimarydifferencesthatwouldoccurinvariousbeefanddairycattlediets.However,amajorconcernwiththeiruseforfinishingcattleisthatanumberofthestudiesusedtodeveloptheequationswerehigh‐foragedietsand/ordidnotuseeithersupplementalfatormonensininthediet.Aspreviouslynoted,whencomparedwithemissionsfromcattlefedtypicalfinishingdietsbasedonsteam‐flakedcorn(SFC)ordry‐rolledcorn(DRC),thisequationgreatlyoverestimatedCH4emissions(Halesetal.,2012).Linearequationsusingnutrientratios(starch:NDF,etc.)werealsodeveloped,butallhadgreaterRMSPEthanthepreviousequation(Ellisetal.,2009).Nonlinearequationswerealsodeveloped.Despitebeingmorebiologicallydefendable,thenonlinearequationsallhadgreaterRMSPEthanthelinearequation.

Inalaterstudy,Yanetal.(2009)developedadditionalequationsusingadatabaseof108measurementsforbeefsteersofvariedbreedinginrespirationchambersandfeddietsthatrangedfrom100to30percentroughage.Theyalsocomparedanumberofequationsdevelopedelsewhere.Equationswere“validated”usingone‐thirdoftheoriginaldataset.Emissionswerehighlycorrelatedtolivebodyweight,DMI,andGEI,butlivebodyweightwasapoorpredictorofentericCH4emissions.TheabilityofanumberofequationstopredictentericCH4measuredinthestudywasvaried(eightpercentoverpredicted,to33percentunderpredicted).ThepoorestresultswerewithfourlinearequationsdevelopedbyEllisetal.(2007)thatusedDMI,MEI,and/orforageintakeasindependentvariables.TheyattributedthepoorresponsetothefactthatagoodportionofthedataforEllisetal.(2007)wasfromgrazinganimalsusingtheSF6technique,whichwouldnotincludeCH4fromthelowergut.TheBlaxterandClapperton(1965)equationdidarespectablejob(93percentofactualwithR2=0.69;meanpredictionerror=0.12;and63percentofmeanssquarepredictionerrorduetorandomeffects,and29percentduetoameanbias).

EmpiricalandMechanisticModel.TheIFSMModel(anditssubsetDairyGEM)(Rotzetal.,2005;Chianeseetal.,2009b;2009c;2009a;2009d)isacombinationempiricalandmechanisticmodelofwholefarmnutrientmanagement.ThesubmodeltoestimateentericCH4emissionsfrombeefordairycattleusestheMits3equationofMillsetal.(2003).Ellisetal.(2007)reportedthattheMillsetal.(2003)equationswerepooratpredictingCH4frombeefcattle,probablybecausetheyweredevelopedfromdairydata.Infact,oneequationthatworkedwellwithdairycowsactuallypredictednegativeCH4emissionsfrombeefcattlefedhigh‐concentrate,low‐foragediets.Thus,thecurrentIFSMmaynotbeappropriatetoestimateentericCH4emissionsfrombeefcattle,especiallyfeedlotcattle.

MechanisticModels.MOLLY(Baldwinetal.,1987;Baldwin,1995)isamechanisticmodelthatestimatesruminalCH4productionbasedonahydrogenbalancewithintherumen.Input

Equation5‐E‐1:LinearModelwiththeLowestRMSPE

. . . . .

Where:

CH4 =Methaneperday(MJday‐1)

MEintake=MEintakein(MJday‐1)

CELL =Celluloseintake(kgday‐1)

HC =Hemicelluloseintake(kgday‐1)

Fat =Fatintake(kgday‐1)


5-137

parameterstothemodelaredailyDMI,chemicalcompositionofthediet,solubilityofproteinandstarch,degradability,ruminalpassagerates,ruminalvolume,andruminalpH.COWPOLL(Dijkstraetal.,1992;Millsetal.,2001)isanothermechanisticmodel.InputparameterstothemodelaresimilartoMOLLY.MOLLYandCOWPOLLbothuseanH‐balancetoestimateentericCH4production.However,theyusedifferentVFAstoichiometrysubmodels.Bothmodelsrequiresignificantinputsthatareprobablybeyondthescopeoftypicalproducers.However,theyareexcellentresearchtools.

TheCornellNetCarbohydrateandProteinSystemmodel(CNCPS,2010)calculatesnutrientrequirements,nutrientinputs,animalproduction(weightgainand/ormilkproduction),andnutrientexcretioninbeefanddairycattle.Itrecentlyaddedasubmodel(VanAmburghetal.,2010)tocalculateentericCH4emissions.ThesubmodelusesanequationofMillsetal.(2003)toestimateentericemissionsfromdairycowsandanequationofEllisetal.(2007)toestimateentericemissionsfrombeefcattle.Atpresent,toourknowledgetherearenocomparisonsorindependentvalidationsofthenewsubmodelsthathavebeenpublished,andtheextenttowhichthemodelisresponsivetomitigationstrategiesisunclear.

ComparativeAnalysesusingIndependentDataSets.SeveralstudieshaveattemptedtoevaluatethepredictiveabilityofentericCH4modelsbyusinganindependentdataset.Benchaaretal.(1998)comparedtwomechanistic(Baldwinetal.,1987;Dijkstraetal.,1992;Baldwin,1995);andtwolinear(BlaxterandClapperton,1965;MoeandTyrrell,1979)modelswithadatasetof32dietsfrom13publicationsintheliterature.Theynotedthatthemechanisticmodelswerebetterpredictorsthantheregressionequations.Thelinearregressionmodelscouldonlyexplain42to57percentofthevariationinpredictedvalues,whereasthemechanisticmodelsexplainedmorethan70percentofthevariation.ThemodelofDijkstraetal.(1992)tendedtounderestimateactualCH4

production(meanerror=0.30Mcalday‐1),withtheerrorbeinggreaterathigherCH4productions.ThemodelofBaldwin(Baldwinetal.,1987;Baldwin,1995)overestimatedCH4productionbyabout0.93Mcalday‐1,primarilyduetoahighintercept.TheequationsofMoeandTyrrell(1979)andBlaxterandClapperton(1965)tendedtooverestimateCH4production,especiallyatlowproductionrates.

ComparativeAnalysis/LactatingandNonlactatingCows.Wilkersonetal.(1995)comparedseveralpublishedequations(Kriss,1930;BratzlerandForbes,1940;Axelsson,1949;BlaxterandClapperton,1965;MoeandTyrrell,1979;HolterandYoung,1992)fortheirabilitytopredictentericCH4productionfromlactatingandnonlactatingHolsteincows.Ingeneral,equationsthatwerebasedontotalDMIoronintakeofdigestedcellulose,hemicellulose,andnonfibercarbohydrates,providedthehighestcorrelationandlowesterrorsofprediction.PredictionequationsthatusedaquadraticfunctionofDMIwerepooratpredictingentericCH4.Ingeneral,theequationspredictedemissionsfromnonlactatingcowsmoreaccuratelythanfromlactatingcows.

ComparativeAnalysisLinearModels.Kebreabetal.(2006)comparedtwolinearmodels(MoeandTyrrell,1979;Millsetal.,2003),anonlinearmodel(Millsetal.,2003),theIPCCTier1andTier2models(IPCC,1997),andadynamicmechanisticmodel(Kebreabetal.,2004)usingdatafromstudiesconductedinNorthAmerica.Theyrecommendedthatthelinearmodelsbeusedwhenthereislimitedinformationonnutrientintakeandwhentheexpectedemissionsarewithintherangeofdatafromwhichthemodelwasdeveloped.ThenonlinearmodelofMillsetal.(2003)couldbeusedforextrapolatingbeyondtherangeofdatausedtodeveloptheequation,butthemechanisticmodelwasrecommendedforevaluationofmitigationoptions.TheIPCCTier1modelwasfoundtobeadequateforgeneralinventorypurposes.ThepredictiveabilityoftheTier2model,whilemostuseful,waslimited.


5-138

ComparativeAnalysisMechanisticModels.Kebreabetal.(2008)alsocomparedtwomechanisticmodels,MOLLY(Baldwinetal.,1987;Baldwin,1995)andCOWPOLL(Dijkstraetal.,1992;Millsetal.,2001;Banninketal.,2006),totheIPCCTier2(2006)andlinearequationofMoeandTyrrell(1979).Usingabeefcattledataset,MOLLYandIPCCtendedtobemoreaccuratethantheothermodels,althoughMOLLYwasmoreprecise.MOLLYandIPCCTier2hadminimalmeanbias,whereasCOWPOLLandtheMoeandTyrrell(1979)equationgreatlyoverpredictedaverageemissions.COWPOLL,whichisbasedontheentericCH4predictionequationsofMillsetal.(2001)andtheupdatedrumenstoichiometryforlactatingcows(Banninketal.,2006),hadthepoorestabilitytopredictentericCH4emissionfromfeedlotcattleandtendedtooverpredictCH4emissions(MJday‐1)byasmuchas50percent.AlthoughonaverageMOLLYandIPCCTier2(2006)gavepredictedvaluessimilartomeasuredvalues,therewasalargevariabilityinindividualanimals,witherrorsof75percentorgreater.Thelargevariabilityinpredictedvaluesindicatesthattherecanbelargeanimal‐to‐animalvariationinentericCH4production,evenwhenanimalsarefedthesamedietsatsimilarfeedintakes.

ComparativeAnalysis/Feedlots.McGinnetal.(2008)comparedmeasured(usingbLSmodel)CH4emissions(entericpluspensurface)fromfeedlotsinAustraliaandCanadawithestimatesusingtheIPCCTier1,IPCCTier2,BlaxterandClapperton(1965),andMoeandTyrrell(1979)equations.TheTier2methodunderestimatedCH4atbothlocations.EstimatesusingtheIPCCTier1methodswereclosetomeasuredvaluesinAustralia;however,Tier1underestimatedvaluesfortheCanadafeedlot.EstimatesmadeusingtheBlaxterandClapperton(1965)andMoeandTyrrell(1979)equationswereclosetomeasuredvaluesinCanada,butoverestimatedvaluesinAustralia.Methaneemissionshadasignificantdielpatternindicatingthatshort‐termmeasurementofCH4emissionsatfeedlotsmayoverestimateorunderestimatedailyemissions.

ComparativeAnalysisofStoichiometricModels.Alemuetal.(2011)comparedentericCH4emissionsfromdairycowsusingavarietyofstoichiometricmodelsofruminalfermentation(Murphyetal.,1982;Banninketal.,2006;Sveinbjornssonetal.,2006;Nozièreetal.,2010),andnotedthatmechanisticmodelssuchasBanninketal.(2006)aremoreaccurateforpredictingentericCH4fromdairycowsthantheIPCCTier2(2006)method.However,thesemodelsrequiredaconsiderablequantityofdataregardingtheanimalsandtheirdiet.

ComparativeAnalysisMeasurementDataandModels.Tomkinsetal.(2011)measuredentericCH4emissionsofsteersonpastureusingamicrometeorologicalmethodandrespirationchambers.EmissionsestimatedusinganEllis(2009)equation(CH4,MJday‐1=3.272+0.736(DMI,kgday‐1))weresimilar(112.7gday‐1)tomeasuredemissions.EstimatesusingtheequationsofKuriharaetal.(1999)asmodifiedbyHunter(2007)(109.1gday‐1),Yanetal.(2009)(105.6gday‐1),andCharmleyetal.(2008)(2008:NABCEMS;100.2gday‐1)wereslightlylower,butnotaslowastheIPCC(2006)model(82.7gday‐1).

ComparativeAnalyses/Models.Legesseetal.(2011)comparedentericCH4emissionestimatesusingMOLLY,COWPOLL,IPCCTier2,andoneequationofEllisetal.(2007)undervariousCanadianbeefcow‐calfmanagementsystems.Differencesamongthemodels(26to35percent)weremuchgreaterthandifferencesamongmanagementsystems(threetofivepercent).Theauthorssuggestedthatthesedifferenceslimitedthemodel’sutilityinpredictingCH4emissionfrombeefcowsystems.

EvaluationofModels.Yanetal.(2000;2009)notedthatCH4production(percentofGEIordigestibleenergy)decreasedwithincreasingDMI(asmultiplesofmaintenance)andwithincreasingforageinthediet.Thus,theysuggestedthatmodelsthatdonotconsiderfeedinglevelwillunderpredictCH4atlowplanesofnutritionandoverpredictentericCH4athighlevelsoffeeding.Similarly,Kebreabetal.(2006)notedthatlinearmodelstendtogiveunrealisticallyhigh


5-139

emissionvalueswhenDMIincreases,whereasnonlinearmodelsgavevaluesapproachingthetheoreticalmaximumemission,whichisbiologicallyreasonable.

AlthoughseveralequationsofEllisetal.(2009)appearedtobegoodpredictorsofentericCH4lossesfromfeedlotcattlebasedonCanadianstudies,whencomparedwithdatafromcattlefedatypicalcorn‐basedfinishingdiet(Halesetal.,2012)mosttendedtogreatlyoverestimateentericlosses.Atthepresenttime,theIPCCTier2modelwithsomemodificationsmaybethemostusefulforpredictionofentericemissionsfromfeedlotbeefcattle.

Chapter5References

Aarnink,A.J.A.,andM.W.A.Verstegen.2007.Nutrition,keyfactortoreduceenvironmentalloadfrompigproduction.LivestockScience,109(1–3):194‐203.

Adviento‐Borbe,M.A.A.,E.F.Wheeler,N.E.Brown,P.A.Topper,etal.2010.Ammoniaandgreenhousegasfluxfrommanureinfreestallbarnwithdairycowsonprecisionfedrations.TransactionsoftheASABE,53:1251‐1266.

Agnew,J.,C.Laguë,J.Schoenau,andR.Farrell.2010.Greenhousegasemissionsmeasured24hoursaftersurfaceandsubsurfaceapplicationofdifferentmanuretypes.TransactionsoftheASABE,53(5):1689‐1701.

Aguerre,M.J.,M.A.Wattiaux,J.M.Powell,G.A.Broderick,etal.2011.Effectofforage‐to‐concentrateratioindairycowdietsonemissionofmethane,carbondioxide,andammonia,lactationperformance,andmanureexcretion.JournalofDairyScience,94(6):3081‐3093.

Alemu,A.W.,J.Dijkstra,A.Bannink,J.France,etal.2011.Rumenstoichiometricmodelsandtheircontributionandchallengesinpredictingentericmethaneproduction.AnimalFeedScienceandTechnology,166‐167(0):761‐778.

Amon,B.,T.Amon,J.Boxberger,andC.Alt.2001.EmissionsofNH3,N2OandCH4fromdairycowshousedinafarmyardmanuretyingstall(housing,manurestorage,manurespreading).NutrientCyclinginAgroecosystems,60(1):103‐113.

Anderson,R.C.,andM.A.Rasmussen.1998.Useofanovelnitrotoxin‐metabolizingbacteriumtoreduceruminalmethaneproduction.BioresourceTechnology,64(2):89‐95.

Anderson,R.C.,T.R.Callaway,J.A.S.VanKessel,Y.S.Jung,etal.2003.Effectofselectnitrocompoundsonruminalfermentation;aninitiallookattheirpotentialtoreduceeconomicandenvironmentalcostsassociatedwithruminalmethanogenesis.BioresourceTechnology,90(1):59‐63.

Applegate,T.,W.Powers,R.Angel,andD.Hoehler.2008.EffectofAminoAcidFormulationandAminoAcidSupplementationonPerformanceandNitrogenExcretioninTurkeyToms.PoultryScience,87(3):514‐520.

Archibeque,S.L.,D.N.Miller,H.C.Freetly,andC.L.Ferrell.2006.Feedinghigh‐moisturecorninsteadofdry‐rolledcornreducesodorouscompoundproductioninmanureoffinishingbeefcattlewithoutdecreasingperformance.JournalofAnimalScience,84(7):1767‐1777.

Arriaga,H.,G.Salcedo,L.Martínez‐Suller,S.Calsamiglia,etal.2010.Effectofdietarycrudeproteinmodificationonammoniaandnitrousoxideconcentrationonatie‐stalldairybarnfloor.JournalofDairyScience,93(7):3158‐3165.

ASABE.2005.ManureProductionandCharacteristics,ASABEStandardD384.2MAR2005(R2010).St.Joseph,MI:AmericanSocietyofAgriculturalandBiologicalEngineers.

Atakora,J.K.A.,S.Möhn,andR.O.Ball.2003.Lowproteindietsmaintainperformanceandreducegreenhousegasproductioninfinisherpigs.Proceedingsofthe2003BanffPorkSeminar,Alberta,Canada.

Atakora,J.K.A.,S.Möhn,andR.O.Ball.2004.Effectsofdietaryproteinreductionongreenhousegasemissionfrompigs.Proceedingsofthe2004BanffPorkSeminar,Alberta,Canada.


5-140

AustralianGreenhouseOffice.2007.Nationalgreenhousegasinventory2005.Canberra,Australia:Dept.oftheEnvironmentandWaterResources.

Axelsson,J.1949.TheamountofproducedmethaneenergyintheEuropeanmetabolicexperimentswithadultcattle.AnnalsoftheRoyalAgriculturalCollegeofSweden,16:404‐419.

Baker,C.1969.Temperaturedependenceofself‐diffusioncoefficientsforgaseousammonia.WashingtonD.C.:LewisResearchCenter,NationalAeronauticsandSpaceAdministration.

Baldwin,R.L.,J.H.M.Thornley,andD.E.Beever.1987.Metabolismofthelactatingcow:II.Digestiveelementsofamechanisticmodel.JournalofDairyResearch,54(01):107‐131.

Baldwin,R.L.1995.ModelingruminantDigestionandMetabolism.London,UK:Chapman&Hall.Ball,R.O.,andS.Möhn.2003.Feedingstrategiestoreducegreenhousegasemissionsfrompigs.

Proceedingsofthe2003BanffPorkSeminar,Alberta,Canada.Bannink,A.,J.Kogut,J.Dijkstra,J.France,etal.2006.Estimationofthestoichiometryofvolatile

fattyacidproductionintherumenoflactatingcows.JournalofTheoreticalBiology,238(1):36‐51.

Beauchemin,K.,M.Kreuzer,F.O’Mara,andT.McAllister.2008.Nutritionalmanagementforentericmethaneabatement:areview.AustralianJournalofExperimentalAgriculture,48:21‐27.

Beauchemin,K.A.,andS.M.McGinn.2005.Methaneemissionsfromfeedlotcattlefedbarleyorcorndiets.JournalofAnimalScience,83(3):653‐661.

Beauchemin,K.A.,andS.M.McGinn.2006a.Methaneemissionsfrombeefcattle:Effectsoffumaricacid,essentialoil,andcanolaoil.JournalofAnimalScience,84(6):1489‐1496.

Beauchemin,K.A.,andS.M.McGinn.2006b.Entericmethaneemissionsfromgrowingbeefcattleasaffectedbydietandlevelofintake.CanadianJournalofAnimalScience,86(3):401‐408.

Beauchemin,K.A.,H.HenryJanzen,S.M.Little,T.A.McAllister,etal.2010.LifecycleassessmentofgreenhousegasemissionsfrombeefproductioninwesternCanada:Acasestudy.AgriculturalSystems,103(6):371‐379.

Benchaar,C.,J.Rivest,C.Pomar,andJ.Chiquette.1998.Predictionofmethaneproductionfromdairycowsusingexistingmechanisticmodelsandregressionequations.JournalofAnimalScience,76(2):617‐627.

Benchaar,C.,C.Pomar,andJ.Chiquette.2001.Evaluationofdietarystrategiestoreducemethaneproductioninruminants:Amodelingapproach.CanadianJournalofAnimalScience,81:563‐574.

Berger,L.L.,andN.R.Merchen.1995.Influenceofproteinlevelonintakeoffeedlotcattle–Roleofruminalammoniasupply.Symposium.IntakeofFeedlotCattle.OklahomaStateUniv.July,1995:942:272‐280.

Bhatta,R.,K.Tajima,N.Takusari,K.Higuchi,etal.2007.Comparisonofinvivoandinvitrotechniquesformethaneproductionfromruminantdiets.Asian‐AustralasianJournalofAnimalSciences,20:1049‐1056.

Bhatti,J.S.,R.Lal,M.A.Price,andM.J.Apps,(eds.).2005.ClimateChangeandManagedEcosystems.BocaRaton,FL:CRCPress.

Bjorneberg,D.L.,A.B.Leytem,D.T.Westermann,P.R.Griffiths,etal.2009.Measurementofatmosphericammonia,methane,andnitrousoxideataconcentrateddairyproductionfacilityinsouthernIdahousingopen‐pathFTIRspectrometry.TransactionsoftheASABE,52(5):1749‐1756.

Blaxter,K.L.,andF.W.Wainman.1964.Theutilizationoftheenergyofdifferentrationsbysheepandcattleformaintenanceandforfattening.JournalofAgriculturalScience,63(01):113‐128.

Blaxter,K.L.,andJ.L.Clapperton.1965.Predictionoftheamountofmethaneproducedbyruminants.BritishJournalofNutrition,19:511‐522.

Bluteau,C.V.,D.I.Massé,andR.Leduc.2009.AmmoniaemissionratesfromdairylivestockbuildingsinEasternCanada.BiosystemsEngineering,103(4):480‐488.


5-141

Boadi,D.A.,K.M.Wittenberg,andW.McCaughey.2002.Effectsofgrainsupplementationonmethaneproductionofgrazingsteersusingthesulphur(SF6)tracergastechnique.CanadianJournalofAnimalScience,82(2):151‐157.

Branine,M.E.,andD.E.Johnson.1990.Levelofintakeeffectsonruminantmethanelossacrossawiderangeofdiets.JournalofAnimalScience,68(Suppl.1):509‐510.

Bratzler,J.W.,andE.B.Forbes.1940.Theestimationofmethaneproductionbycattle.JournalofNutrition,19:611‐613.

Brooks,J.P.,andM.R.McLaughlin.2009.Antibioticresistantbacterialprofilesofanaerobicswinelagooneffluent.JournalofEnvironmentalQuality,38(6):2431‐2437.

Cabrera,M.L.,andS.C.Chiang.1994.WaterContentEffectonDenitrificationandAmmoniaVolatilizationinPoultryLitter.SoilSci.Soc.Am.J.,58(3):811‐816.

Cambardella,C.A.,T.B.Moorman,andJ.W.Singer.2010.Soilnitrogenresponsetocouplingcovercropswithmanureinjection.NutrientCyclinginAgroecosystems,87(3):383‐393.

Canh,T.T.,M.W.A.Verstegen,A.J.A.Aarnink,andJ.W.Schrama.1997.Influenceofdietaryfactorsonnitrogenpartitioningandcompositionofurineandfecesoffatteningpigs.JournalofAnimalScience,75:700‐706.

Canh,T.T.,A.J.A.Aarnink,Z.Mroz,A.W.Jongbloed,etal.1998a.Influenceofelectrolytebalanceandacidifyingcalciumsaltsinthedietofgrowing‐finishingpigsonurinarypH,slurrypHandammoniavolatilisationfromslurry.Livest.Prod.Sci.,56:1‐13.

Canh,T.T.,A.J.A.Aarnink,J.B.Schutte,A.L.Sutton,etal.1998b.Dietaryproteinaffectsnitrogenexcretionandammoniaemissionfromslurryofgrowingfinishingpigs.LivestockProductionScience,56:181‐191.

Cantrell,K.B.,T.Ducey,K.S.Ro,andP.G.Hunt.2008a.Livestockwaste‐to‐bioenergygenerationopportunities.BioresourceTechnology,99(17):7941‐7953.

Cantrell,K.B.,K.S.Ro,andP.G.Hunt.2008b.Thermalcharacterizationofswinemanure:Bioenergyfeedstockpotential.

Cantrell,K.B.,K.C.Stone,P.G.Hunt,K.S.Ro,etal.2009.BioenergyfromCoastalbermudagrassreceivingsubsurfacedripirrigationwithadvance‐treatedswinewastewater.BioresourceTechnology,100(13):3285‐3292.

Cantrell,K.B.,P.G.Hunt,K.S.Ro,K.C.Stone,etal.2010a.Thermogravimetriccharacterizationofirrigatedbermudagrassasacombustionfeedstock.TransactionsoftheASABE,53(2):413‐420.

Cantrell,K.B.,J.H.MartinIi,andK.S.Ro.2010b.Applicationofthermogravimetricanalysisfortheproximateanalysisoflivestockwastes.JournalofASTMInternational,7(3).

Capper,J.L.,R.A.Cady,andD.E.Bauman.2009.Theenvironmentalimpactofdairyproduction:1944comparedwith2007.JournalofAnimalScience,87(6):2160‐2167.

Carmean,B.R.,K.A.Johnson,D.E.Johnson,andL.W.Johnson.1992.Maintenanceenergyrequirementofllama.AmericanJournalofVeterinaryReserach,53:1696‐1698.

Carr,L.E.,F.W.Wheaton,andL.W.Douglass.1990.Empiricalmodelstodetermineammoniaconcentrationsfrombroilerchickenlitter.Trans.ASAE,33:1337‐1342.

Cassel,T.,L.Ashbaugh,R.Flocchini,andD.Meyer.2005.Ammoniaemissionfactorsforopen‐lotdairies:Directmeasurementsandestimationbynitrogenintake.JournaloftheAir&WasteManagementAssociation,55:826‐833.

CDM.2012.Projectandleakageemissionsfromanaerobicdigesters.Ver.01.0.0:CleanDevelopmentMechanism.

Charmley,E.,M.L.Stephens,andP.M.Kennedy.2008.PredictinglivestockproductivityandmethaneemissionsinnorthernAustralia:developmentofabio‐economicmodelingapproach.AustralianJournalofExperimentalAgriculture,49:109‐113.


5-142

Chastain,J.P.,W.D.Lucas,J.E.Albrecht,J.C.Pardue,etal.1998.SolidsandNutrientRemovalFromLiquidSwineManureUsingaScrewPressSeparator,ASAEPaperNo.98‐4110.St.Joseph,MI:AmericanSocietyofAgriculturalEngineers.

Chastain,J.P.,M.B.Vanotti,andM.M.Wingfield.2001.EffectivenessofLiquid‐SolidSeparationforTreatmentofFlushedDairyManure:ACaseStudy.TransactionsoftheAmericanSocietyofAgriculturalEngineers,17(3):343‐354.

Chen,G.Q.,L.Shao,Z.M.Chen,Z.Li,etal.2011.Low‐carbonassessmentforecologicalwastewatertreatmentbyaconstructedwetlandinBeijing.EcologicalEngineering,37(4):622‐628.

Chianese,D.S.,C.A.Rotz,andT.L.Richard.2009a.Simulationofcarbondioxideemissionsfromdairyfarmstoassessgreenhousegasreductionstrategies.Trans.ASABE,52:1301‐1312.

Chianese,D.S.,C.A.Rotz,andT.L.Richard.2009b.Whole‐farmgreenhousegasemissions:AreviewwithapplicationtoaPennsylvaniadairyfarm.AppliedEngineeringinAgriculture,25:431‐442.

Chianese,D.S.,C.A.Rotz,andT.L.Richard.2009c.Simulationofmethaneemissionsfromdairyfarmstoassessgreenhousegasreductionstrategies.Trans.ASABE,52:1313‐1323.

Chianese,D.S.,C.A.Rotz,andT.L.Richard.2009d.Simulationofnitrousoxideemissionsfromdairyfarmstoassessgreenhousegasreductionstrategies.Trans.ASABE,52:1325‐1335.

Chiumenti,R.,L.Donatoni,andS.Guercini.1987.Liquid/SolidSeparationTestsonBeefCattleManure.ProceedingsoftheSeminarofthe2ndTechnicalSectionoftheC.I.G.R.,UbranaChampaign,IL,June22‐26,1987.

Clark,O.,S.Moehn,J.Edeogu,J.Price,etal.2005.Manipulationofdietaryproteinandnonstarchpolysaccharidetocontrolswinemanureemissions.JournalofEnvironmentalQuality,34:1461‐1466.

CNCPS.CornellNetCarbohydrateandProteinSystem.Retrievedfromhttp://www.cncps.cornell.edu.

Cole,N.A.,andJ.E.McCroskey.1975.EffectsofHemiacetalofChloralandStarchonthePerformanceofBeefSteers.JournalofAnimalScience,41(6):1735‐1741.

Cole,N.A.,P.J.Defoor,M.L.Galyean,G.C.Duff,etal.2006.Effectsofphasefeedingofcrudeproteinonperformance,carcasscharacteristics,serumureanitrogenconcentrationsandmanurenitrogeninfinishingbeesteers.JournalofAnimalScience,84:3421‐3432.

Cole,N.A.,R.W.Todd,D.B.Parker,andM.Rhoades.2007b.Challengesinusingfluxchamberstomeasureammoniaemissionsformsimulatedfeedlotpensurfacesandretentionponds.ProceedingsoftheInternationalSymposiumOnAirQualityandWasteManagementforAgriculture,Sept.16‐19,2007,Broomfield,CO.

Cole,N.A.,A.M.Mason,R.W.Todd,andD.B.Parker.2009a.Effectsofurineapplicationonchemistryoffeedlotpensurfaces.JournalofAnimalScience,87:ESuppl.2:148(Abstract).

Cole,N.A.,A.M.Mason,R.W.Todd,M.Rhoades,etal.2009b.ChemicalCompositionofPenSurfaceLayersofBeefCattleFeedyards.TheProfessionalAnimalScientist,25(5):541‐552.

Converse,J.C.,R.G.Koegel,andR.J.Straub.1999.NutrientandSolidsSeparationofDairyandSwineManureUsingaScrewPressSeparator,ASAEPaperNo.99‐4050.St.Joseph,MI:AmericanSocietyofAgriculturalEngineers.

Cooprider,K.L.,F.M.Mitloehner,T.R.Famula,E.Kebreab,etal.2011.Feedlotefficiencyimplicationsongreenhousegasemissionandsustainability.JournalofAnimalScience,(inpress).

CornellUniversityDepartmentofAnimalScience.2010.CNCPS.Corrigan,M.E.,T.J.Klopfenstein,G.E.Erickson,N.F.Meyer,etal.2009.Effectsoflevelofcondensed

distiller’ssolublesincorndrieddistillersgrainsonintake,dailyweightgain,anddigestibilityingrowingsteersfedforagediets.JournalofAnimalScience,87:4073‐4081.

Cottle,D.J.,J.V.Nolan,andS.G.Wiedemann.2011.Ruminantentericmethanemitigation:areview.AnimalProductionScience,51(6):491‐514.


5-143

Coufal,C.,C.Chavez,P.Niemeyer,andJ.Carey.2006.Nitrogenemissionsfrombroilersmeasuredbymassbalanceovereighteenconsecutiveflocks.PoultryScience,85(3):384‐391.

Crutzen,P.J.,I.Aselmann,andW.Seiler.1986.Methaneproductionbydomesticanimals,wildruminants,otherherbivorousfauna,andhumans.TellusB,38B(3‐4):271‐284.

Davies,P.R.2011.Intensiveswineproductionandporksafety.FoodbornePathogensandDisease,8(2):189‐201.

Delfino,J.,G.W.Mathison,andM.W.Smith.1988.Effectoflasalocidonfeedlotperformanceandenergypartitioningincattle.JournalofAnimalScience,66:236‐241.

Delmore,R.J.,J.M.Hodgen,andB.J.Johnson.2010.PerspectivesontheapplicationofzilpaterolhydrochlorideintheUnitedStatesbeefindustry.JournalofAnimalScience,88:2825‐2828.

DeRamus,H.,T.Clement,D.Giampola,andP.Dickison.2003.Methaneemissionsofbeefcattleonforages:efficiencyofgrazingmanagementsystems.JournalofEnvironmentalQuality,21:269‐277.

Dibner,J.,andJ.Richards.2005.Antibioticgrowthpromotersinagriculture:historyandmodeofaction.PoultryScience,84(4):634‐643.

Dijkstra,J.,H.D.S.C.Neal,D.E.Beever,andJ.France.1992.Simulationofnutrientdigestion,absorptionandoutflowintherumen:modeldescription.JournalofNutrition,122(1992):2239‐2256.

Dijkstra,J.,E.Kebreab,J.A.N.Mills,W.F.Pellikaan,etal.2007.Predictingtheprofileofnutrientsavailableforabsorption:fromnutrientrequirementtoanimalresponseandenvironmentalimpact.Animal,1(1):99‐111.

Dini,Y.,J.Gere,C.Briano,M.Manetti,etal.2012.MethaneemissionandmilkproductionofdairycowsgrazingpasturesrighinlegumesorrichingrassesinUruguay.Animals,2:288‐300.

Dodla,S.K.,J.J.Wang,R.D.DeLaune,andR.L.Cook.2008.Denitrificationpotentialanditsrelationtoorganiccarbonqualityinthreecoastalwetlandsoils.ScienceoftheTotalEnvironment,407(1):471‐480.

Dong,R.,Y.Zhang,L.L.Christianson,T.L.Funk,etal.2009.ProductdistributionandimplicationofhydrothermalconversionofswinemanureatlowTemperatures.TransactionsoftheASABE,52(4):1239‐1248.

Eckard,R.J.,C.Grainger,andC.A.M.deKlein.2010.Optionsfortheabatementofmethaneandnitrousoxidefromruminantproduction:Areview.130(1):47‐56.

Elam,N.A.,J.T.Vasconcelos,G.Hilton,D.L.VanOverbeke,etal.2009.Effectofzilpaterolhydrochloridedurationoffeedingonperformanceandcarcasscharacteristicsoffeedlotcattle.JournalofAnimalScience,87:2133‐2141.

Elgood,Z.,W.D.Robertson,S.L.Schiff,andR.Elgood.2010.Nitrateremovalandgreenhousegasproductioninastream‐beddenitrifyingbioreactor.EcologicalEngineering,36(11):1575‐1580.

Elliot,H.A.,andN.E.Collins.1982.Factorsaffectingammoniareleaseinbroilerhouses.Trans.ASAE,25:413‐418.

Ellis,J.L.,E.Kebreab,N.E.Odongo,B.W.McBride,etal.2007.PredictionofMethaneProductionfromDairyandBeefCattle.JournalofDairyScience,90(7):3456‐3466.

Ellis,J.L.,E.Kebreab,N.E.Odongo,K.Beauchemin,etal.2009.Modelingmethaneproductionfrombeefcattleusinglinearandnonlinearapproaches.JournalofAnimalScience,87(4):1334‐1345.

Ellis,S.,J.Webb,T.Misselbrook,andD.Chadwick.2001.Emissionofammonia(NH3),nitrousoxide(N2O)andmethane(CH4)fromadairyhardstandingintheUK.NutrientCyclinginAgroecosystems,60(1):115‐122.

Ewan,R.C.1989.Predictingtheenergyutilizationofdietsandfeedingredientsbypigs.InEnergyMetabolism,EuropeanAssociationofAnimalProductionBulletinNo.43,Y.v.d.HoningandW.H.Close(eds.).PudocWageningen,Netherlands.


5-144

Faubert,P.,P.Tiiva,Å.Rinnan,S.Räty,etal.2010.Effectofvegetationremovalandwatertabledrawdownonthenon‐methanebiogenicvolatileorganiccompoundemissionsinborealpeatlandmicrocosms.AtmosphericEnvironment,44(35):4432‐4439.

Faulwetter,J.L.,V.Gagnon,C.Sundberg,F.Chazarenc,etal.2009.Microbialprocessesinfluencingperformanceoftreatmentwetlands:Areview.EcologicalEngineering,35(6):987‐1004.

Ferguson,N.,R.Gates,J.Taraba,A.Cantor,etal.1998a.Theeffectofdietarycrudeproteinongrowth,ammoniaconcentration,andlittercompositioninbroilers.PoultryScience,77(10):1481‐1487.

Ferguson,N.,R.Gates,J.Taraba,A.Cantor,etal.1998b.Theeffectofdietaryproteinandphosphorusonammoniaconcentrationandlittercompositioninbroilers.PoultryScience,77(8):1085‐1093.

Ferket,P.,E.Heugten,T.Kempen,andR.Angel.2002.Nutritionalstrategiestoreduceenvironmentalemissionfromnonruminants.JournalofAnimalScience,80(Suppl.2):168‐182.

Fernandes,L.,E.McKyes,andL.Obidniak.1988.Performanceofacontinuousbeltmicroscreeningunitforsolidliquidseparationofswinewaste.TransactionsoftheCSAE,30(1):151‐155.

Fey,A.,G.Benckiser,andJ.C.G.Ottow.1999.Emissionsofnitrousoxidefromaconstructedwetlandusingagroundfilterandmacrophytesinwaste‐waterpurificationofadairyfarm.BiologyandFertilityofSoils,29(4):354‐359.

Flesch,T.K.,J.D.Wilson,L.A.Harper,andB.P.Crenna.2005.Estimatinggasemissionsfromafarmwithaninverse‐dispersiontechnique.AtmosphericEnvironment,39(27):4863‐4874.

Flesch,T.K.,L.A.Harper,J.M.Powell,andJ.D.Wilson.2009.Inverse‐dispersioncalculationofammoniaemissionsfromWisconsindairyfarms,52:TransactionsoftheASABE.

Flesch,T.K.,R.L.Desjardins,andD.Worth.2011.Fugitivemethaneemissionsfromanagriculturalbiodigester.BiomassandBioenergy,35(9):3927‐3935.

Florin,N.H.,A.R.Maddocks,S.Wood,andA.T.Harris.2009.High‐temperaturethermaldestructionofpoultryderivedwastesforenergyrecoveryinAustralia.WasteManagement,29(4):1399‐1408.

Ford,M.,andR.Fleming.2002.MechnicalSolid‐LiquidSeparationofLivestockManureLiteratureReview:UniversityofGuelph.

Fournier.RotaryPress.Retrievedfromhttp://www.rotary‐press.com/.Fowler,D.,M.Coyle,C.Flechard,K.Hargreaves,etal.2001.Advancesinmicrometeorological

methodsforthemeasurementandinterpretationofgasandparticlenitrogenfluxes.PlantandSoil,228(1):117‐129.

Freeman,C.,M.A.Lock,S.Hughes,B.Reynolds,etal.1997.Nitrousoxideemissionsandtheuseofwetlandsforwaterqualityamelioration.EnvironmentalScienceandTechnology,31(8):2438‐2440.

Freetly,H.C.,andT.M.Brown‐Brandl.2013.Entericmethaneproductionfrombeefcattlethatvaryinfeedefficiency.JournalofAnimalScience,91(10):4826‐4831.

Fukummoto,Y.,T.Osada,D.Hanajima,andK.Haga.2003.PatternsandquantitiesofNH3,N2O,andCH4emissionsduringswinemanurecompostingwithoutforcedaeration‐effectofcompostpilescale.BioresourceTechnology,89:109‐114.

Galbraith,J.K.,G.W.Mathison,R.J.Hudson,T.A.McAllister,etal.1998.Intake,digestibility,methaneandheatproductioninbison,wapitiandwhite‐taileddeer.Canadianjournalofanimalscience.,78(4):681‐691.

Gao,F.,andS.R.Yates.1998.Simulationofenclosure‐basedmethodsformeasuringgasemissionsfromsoiltotheatmosphere.JournalofGeophysicalResearch,103(D20):26127‐26136.

Gilbertson,C.B.,andJ.A.Nienaber.1978.SeparationofCoarseSolidsfromBeefCattleManure.TransactionsoftheAmericanSocietyofAgriculturalEngineers,21(6):1185‐1188.


5-145

Gleghorn,J.F.,N.A.Elam,M.L.Galyean,G.C.Duff,etal.2004.Effectsofcrudeproteinconcentrationanddegradabilityonperformance,carcasscharacteristics,andserumureanitrogenconcentrationsinfinishingbeefsteers.JournalofAnimalScience,82:2705‐2717.

Glerum,J.C.,G.Klomp,andH.R.Poelma.1971.TheSeparationofSolidandLiquidPartsofPigSlurry.Proceedingsofthe1stInternationalSymposiumonLivestockWastes,Columbus,OH,April19‐22,1971.

Goopy,J.P.,R.Woodgate,A.Donaldson,D.L.Robinson,etal.2011.Validationofashort‐termmethanemeasurementusingportablestaticchamberstoestimatedailymethaneproductioninsheep.AnimalFeedScienceandTechnology,166‐167(0):219‐226.

Gould‐Wells,D.,andD.W.Williams.2004.Biogasproductionfromacoveredlagoondigesterandutilizationinamicroturbine.

Guan,H.,K.M.Wittenberg,K.H.Ominski,andD.O.Krause.2006.Efficacyofionophoresincattledietsformitigationofentericmethane.JournalofAnimalScience,84(7):1896‐1906.

Hales,K.E.,N.A.Cole,andJ.C.MacDonald.2012.Effectsofcornprocessingmethodanddietaryinclusionofwetdistillersgrainwithsolublesonenergymetabolismandentericmethaneemissionsoffinishingcattle.JournalofAnimalScience,90:3174‐3185.

Hales,K.E.,N.A.Cole,andJ.C.MacDonald.2013.Effectsofincreasingconcentrationsofwetdistillersgrainswithsolublesinsteam‐flakedcorn‐baseddietsonenergymetabolism,carbon‐nitrogenbalance,andentericmethaneemissionsofcattle.JournalofAnimalScience,91:819‐828.

Hales,K.E.,T.M.Brown‐Brandl,andH.C.Freetly.2014.Effectsofdecreaseddietaryroughageconcentrationonenergymetabolismandnutrientbalanceinfinishingbeefcattle.JournalofAnimalScience,92:264‐271.

Hamilton,S.W.,E.J.DePeters,J.A.McGarvey,J.Lathrop,etal.2010.GreenhouseGas,AnimalPerformance,andBacterialPopulationStructureResponsestoDietaryMonensinFedtoDairyCows.JournalofEnvironmentalQuality,39(1):106‐114.

Hammer,D.A.,(ed.)1989.ConstructedWetlandsforWastewaterTreatment:Municipal,IndustrialandAgricultural.Chelsea,MI:LewisPublishers.

Hanni,S.,J.DeRouchey,M.Tokach,R.Goodband,etal.2007.Theeffectsofdietarychicoryandreducednutrientdietsoncompositionandodorofstoredswinemanure.TheProfessionalAnimalScientist,23:438‐447.

Hansen,R.R.,D.A.Nielsen,A.Schramm,L.P.Nielsen,etal.2009.Greenhousegasmicrobiologyinwetanddrystrawcrustcoveringpigslurry.JournalofEnvironmentalQuality,38(3):1311‐1319.

Hare,E.,H.D.Norman,andJ.R.Wright.2006.SurvivalrateandproductiveherdlifeofdairycattleintheUnitedStates.JournalofDairyScience,89(3713‐3720).

Harper,L.A.,O.T.Denmead,J.R.Freney,andF.M.Byers.1999.Directmeasurementsofmethaneemissionsfromgrazingandfeedlotcattle.JournalofAnimalScience,77(6):1392‐1401.

Harper,L.A.2005.Ammonia:MeasurementIssues.InMicrometeorologyinAgriculturalSystems,J.L.HatfieldandJ.M.Baker(eds.).Madison,WI:AmericanSocietyofAgronomy,CropScienceSocietyofAmerica,SoilScienceSocietyofAmerica.

Harper,L.A.,O.T.Denmead,andT.K.Flesch.2011.Micrometeorologicaltechniquesformeasurementofentericgreenhousegasemissions.AnimalFeedScienceandTechnology,166‐167(0):227‐239.

Harrington,C.,andM.Scholz.2010.Assessmentofpre‐digestedpiggerywastewatertreatmentoperationswithsurfaceflowintegratedconstructedwetlandsystems.BioresourceTechnology,101(20):7713‐7723.

Harrington,R.,andR.McInnes.2009.IntegratedConstructedWetlands(ICW)forlivestockwastewatermanagement.BioresourceTechnology,100(22):5498‐5505.

Hartung,J.,andV.Phillips.1994.Controlofgaseousemissionsfromlivestockbuildingsandmanurestores.JournalofAgriculturalEngineeringResearch,57:173‐189.


5-146

Hatfield,J.L.,andR.L.Pfeiffer.2005.Evaluationoftechnologiesforambientairmonitoringatconcentratedanimalfeedingoperations.

Havenstein,G.,P.Ferket,andM.Qureshi.2003.Growth,livability,andfeedconversionof1957versus2001broilerswhenfedrepresentative1957and2001broilerdiets.PoultryScience,82(10):1500‐1508.

Havenstein,G.B.,P.R.Ferket,J.L.Grimes,M.A.Qureshi,etal.2007.ComparisonofthePerformanceof1966‐Versus2003‐TypeTurkeysWhenFedRepresentative1966and2003TurkeyDiets:GrowthRate,Livability,andFeedConversion.PoultryScience,86(2):232‐240.

Hayes,E.,A.Leek,T.Curran,V.Dodd,etal.2004.Theinfluenceofdietcrudeproteinlevelonodourandammoniaemissionsfromfinishingpighouses.BioresourceTechnology,91:309‐315.

He,B.,Y.Zhang,Y.Yin,T.L.Funk,etal.2001.EffectsoffeedstockpH,initialCOaddition,andtotalsolidscontentonthethermochemicalconversionprocessofswinemanure.TransactionsoftheAmericanSocietyofAgriculturalEngineers,44(3):697‐701.

He,B.J.,Y.Zhang,Y.Yin,T.L.Funk,etal.2000.Operatingtemperatureandretentiontimeeffectsonthethermochemicalconversionprocessofswinemanure.TransactionsoftheAmericanSocietyofAgriculturalEngineers,43(6):1821‐1825.

Hegarty,R.S.,J.P.Goopy,R.M.Herd,andB.McCorkell.2007.Cattleselectedforlowerresidualfeedintakehavereduceddailymethaneproduction.JournalofAnimalScience,85(6):1479‐1486.

Hegg,R.O.,R.E.Larson,andJ.A.Moore.1981.MechanicalLiquid‐SolidSeparationinBeef,Dairy,andSwineWasteSlurries.24(1):0159‐0163.

Hellebrand,H.J.,andW.D.Kalk.2000.Emissionscausedbymanurecomposting.AgrartechnischeForschung,6(2):26‐31.

Herschler,R.C.,A.W.Olmsted,A.J.Edwards,R.L.Hale,etal.1995.Productionresponsestovariousdosesandratiosofestradiolbenzoateandtrenboloneacetateimplantsinsteersandheifers.JournalofAnimalScience,73:2873‐2881.

Hill,G.M.,K.L.Richardson,andP.R.Utley.1988.Feedlotperformanceandpregnancyinhibitionofheiferstreatedwithdepot‐formulatedmelengestrolacetate.JournalofAnimalScience,66:2435‐2442.

Holmberg,R.D.,D.T.Hill,T.J.Prince,andN.J.VanDyke.1983.PotentialofSolid‐LiquidSeparationofSwineWastesforMethaneProduction.TransactionsoftheAmericanSocietyofAgriculturalEngineers,26(6):1803‐1807.

Holter,J.B.,andA.J.Young.1992.MethanePredictioninDryandLactatingHolsteinCows.JournalofDairyScience,75(8):2165‐2175.

Howden,S.M.,D.H.White,G.M.McKeon,J.C.Scanlan,etal.1994.Methodsforexploringmanagementoptionstoreducegreenhousegasemissionsfromtropicalgrazingsystems.ClimaticChange,27(1):49‐70.

Hristov,A.N.,M.Hanigan,A.Cole,R.Todd,etal.2011.Review:Ammoniaemissionsfromdairyfarmsandbeeffeedlots1.CanadianJournalofAnimalScience,91(1):1‐35.

Hristov,A.N.2012.Historic,preEuropeansettlement,andpresent‐daycontributionofwildruminantstoentericmethaneemissionsintheUnitedStates.JournalofAnimalScience,90:1371‐1375.

Hunt,P.G.,A.A.Szögi,F.J.Humenik,J.M.Rice,etal.2002.Constructedwetlandsfortreatmentofswinewastewaterfromananaerobiclagoon.TransactionsoftheASAE,45(3):639‐647.

Hunt,P.G.,T.A.Matheny,andA.A.Szogi.2003.Denitrificationinconstructedwetlandsusedfortreatmentofswinewastewater.JournalofEnvironmentalQuality,32(2):727‐735.

Hunt,P.G.,M.A.Matheny,andK.S.Ro.2007.Nitrousoxideaccumulationinsoilsfromriparianbuffersofacoastalplainwatershed‐carbon/nitrogenratiocontrol.J.Environ.Qual.,36:1368‐1376.

Hunter,R.A.2007.Methaneproductionbycattleinthetropics.BritishJournalofNutrition,98(03):657‐657.


5-147

Hutchinson,G.L.,andA.R.Mosier.1981.ImprovedSoilCoverMethodforFieldMeasurementofNitrousOxideFluxes1.SoilSci.Soc.Am.J.,45(2):311‐316.

Hwang,S.,K.Jang,H.Jang,J.Song,etal.2006.Factorsaffectingnitrousoxideproduction:Acomparisonofbiologicalnitrogenremovalprocesseswithpartialandcompletenitrification.Biodegradation,17(1):19‐29.

Insam,H.,andB.Wett.2008.ControlofGHGemissionatthemicrobialcommunitylevel.WasteManagement,28(4):699‐706.

IPCC.1997.Revised1996IPCCGuidelinesforNationalGreenhouseGasInventories,PreparedbytheNationalGreenhouseGasInventoriesProgramme.Bracknell,UK:IntergovernmentalPanelonClimateChange.http://www.ipcc‐nggip.iges.or.jp/public/2006gl/vol4.html.

IPCC.2000.GoodPracticeGuidanceandUncertaintyManagementinNationalGreenhouseGasInventories:IntergovernmentalPanelonClimateChange.

IPCC.2006.2006IPCCGuidelinesforNationalGreenhouseGasInventories,PreparedbytheNationalGreenhouseGasInventoriesProgramme.Japan:IntergovernmentalPanelonClimateChange.http://www.ipcc‐nggip.iges.or.jp/public/2006gl/vol4.html.

Jarecki,M.K.,T.B.Parkin,A.S.K.Chan,J.L.Hatfield,etal.2008.Greenhousegasemissionsfromtwosoilsreceivingnitrogenfertilizerandswinemanureslurry.JournalofEnvironmentalQuality,37(4):1432‐1438.

Jarecki,M.K.,T.B.Parkin,A.S.K.Chan,T.C.Kaspar,etal.2009.Covercropeffectsonnitrousoxideemissionfromamanure‐treatedMollisol.Agriculture,EcosystemsandEnvironment,134(1‐2):29‐35.

Jin,Y.,Z.Hu,andZ.Wen.2009.Enhancinganaerobicdigestibilityandphosphorusrecoveryofdairymanurethroughmicrowave‐basedthermochemicalpretreatment.WaterResearch,43(14):3493‐3502.

Johansson,A.E.,Å.KasimirKlemedtsson,L.Klemedtsson,andB.H.Svensson.2003.Nitrousoxideexchangeswiththeatmosphereofaconstructedwetlandtreatingwastewater:Parametersandimplicationsforemissionfactors.Tellus,SeriesB:ChemicalandPhysicalMeteorology,55(3):737‐750.

Johnson,D.E.1972.EffectsofaHemiacetalofChloralandStarchonMethaneProductionandEnergyBalanceofSheepFedaPelletedDiet.JournalofAnimalScience,35(5):1064‐1068.

Johnson,D.E.1974.AdaptationalResponsesinNitrogenandEnergyBalanceofLambsFedaMethaneInhibitor.JournalofAnimalScience,38(1):154‐157.

Johnson,D.E.,T.M.Hill,B.R.Carmen,M.E.Branine,etal.1991.Newperspectivesonruminantmethaneemissions.InEnergyMetabolismofFarmAnimals,C.WenkandM.Boessinger(eds.).Zurich,Switzerland:EuropeanAssociationforAnimalProduction.

Johnson,K.,M.Huyler,H.Westberg,B.Lamb,etal.1994.Measurementofmethaneemissionsfromruminantlivestockusingasulfurhexafluoridetracertechnique.EnvironmentalScience&Technology,28(2):359‐362.

Johnson,K.A.,andD.E.Johnson.1995.Methaneemissionsfromcattle.JournalofAnimalScience,73(8):2483‐2492.

Jones,F.M.,F.A.Phillips,T.Naylor,andN.B.Mercer.2011.MethaneemissionsfromgrazingAngusbeefcowsselectedfordivergentresidualfeedintake.AnimalFeedScienceandTechnology,166‐167(0):302‐307.

Jungbluth,T.,E.Hartung,andG.Brose.2001..Greenhousegasemissionsfromanimalhousingandmanurestores.NutrientCyclinginAgroecosystems,60:133‐145.

Kadlec,R.H.,andR.L.Knight.1996.TreatmentWetlands.BocaRation,FL:LewisPublishers.Kebreab,E.,J.A.N.Mills,L.A.Crompton,A.Bannink,etal.2004.Anintegratedmathematicalmodelto

evaluatenutrientpartitionindairycattlebetweentheanimalanditsenvironment.AnimalFeedScienceandTechnology,112(1‐4):131‐154.


5-148

Kebreab,E.,K.Clark,C.Wagner‐Riddle,andJ.France.2006.MethaneandnitrousoxideemissionsfromCanadiananimalagriculture:Areview.Canadianjournalofanimalscience.,86(2):135‐137.

Kebreab,E.,K.A.Johnson,S.L.Archibeque,D.Pape,etal.2008.ModelforestimatingentericmethaneemissionsfromUnitedStatesdairyandfeedlotcattle.JournalofAnimalScience,86(10):2738‐2748.

Kebreab,E.,J.Dijkstra,A.Bannink,andJ.France.2009.Recentadvancesinmodelingnutrientutilizationinruminants.JournalofAnimalScience,87(14suppl):E111‐E122.

Kelliher,F.M.,andH.Clark.2010.Methaneemissionsfrombison‐AnhistoricherdestimatefortheNorthAmericanGreatPlains.AgriculturalandForestMeteorology,150:473‐477.

Kennedy,P.M.,andE.Charmley.2012.MethaneyieldsfromBrahmancattlefedtropicalgrassesandlegumes.AnimalProductionScience,52(4):225‐239.

Kienbusch,M.R.1986.Measurementofgaseousemissionratesfromlandsurfacesusinganemission‐isolationfluxchamber.User'sguide.PB‐86‐223161/XABUnitedStatesWedFeb0615:30:17EST2008NTIS,PCA04/MFA01.GRA;ERA‐12‐001567;EDB‐86‐185667English.

Kim,I.,P.Ferket,W.Powers,H.Stein,etal.2004.Effectsofdifferentdietaryacidifiersourcesofcalciumandphosphorusonammonia,methaneandodorantemissionfromgrowing‐finishingpigs..Asian‐AustralasianJournalofAnimalSciences,17:1131‐1138.

Kinsman,R.,F.D.Sauer,H.A.Jackson,andM.S.Wolynetz.1995.MethaneandCarbonDioxideEmissionsfromDairyCowsinFullLactationMonitoredoveraSix‐MonthPeriod.JournalofDairyScience,78(12):2760‐2766.

Kirchgessner,M.,M.Kreuzer,H.Muller,andW.Windisch.1991.Releaseofmethaneandcarbondioxidebythepig.AgriculturalandBiologicalResearch,44:103‐133.

Klein,L.,andA.D.G.Wright.2006.Constructionandoperationofopen‐circuitmethanechambersforsmallruminants.Australianjournalofexperimentalagriculture.,46(10):1257‐1262.

Klemedtsson,L.,K.VonArnold,P.Weslien,andP.Gundersen.2005.SoilCNratioasascalarparametertopredictnitrousoxideemissions.GlobalChangeBiology,11(7):1142‐1147.

Klieve,A.V.,andR.S.Hegarty.1999.Opportunitiesforbiologicalcontrolofruminalmethanogenesis:CSIRO.

Koelsch,R.,andR.Stowell.2005.AmmoniaEmissionsEstimator.Lincoln,NE:UniversityofNebraska.http://www.msue.msu.edu/objects/content_revision/download.cfm/revision_id.515204/workspace_id.27335/Forms%20for%20Estimating%20Swine%20and%20Dairy%20Emissions.pdf/.

Krehbiel,C.R.,S.R.Rust,G.Zhang,andS.E.Gilliland.2003.Bacterialdirect‐fedmicrobialsinruminantdiets:Performanceresponseandmodeofaction.JournalofAnimalScience,81(E.Suppl.2):E120‐E132.

Kreikemeier,W.M.,andT.L.Mader.2004.Effectsofgrowth‐promotingagentsandseasononyearlingfeedlotheiferperformance.JournalofAnimalScience,82:2481‐2488.

Kriss,M.1930.Quantitativerelationsofthedrymatterofthefoodconsumed,theheatproduction,thegaseousoutgo,andtheinsensiblelossinbodyweightofcattle.JournalofAgriculturalResearch,40:283‐295.

KSU.2012.FocusonFeedlots.RetrievedDecember20fromhttp://www.asi.ksu.edu/p.aspx?tabid=302.

Kurihara,M.,T.Magner,R.A.Hunter,andG.J.McCrabb.1999.Methaneproductionandenergypartitionofcattleinthetropics.BritishJournalofNutrition,81(03):227‐234.

Kurup,R.2003.Performanceofaresidentialscaleplugflowanaerobicreactorfordomesticorganicwastetreatmentandbiogasgeneration.InORBIT2003OrganicRecoveryandBIologicalTreatmentProceedingsoftheFourthInternationalConferenceofORBITAssociationon


5-149

BiologicalProcessingofOrganics:AdvancesforaSustainableSociety.Perth,WesternAustralia.

Lassey,K.R.2007.Livestockmethaneemission:Fromtheindividualgrazinganimalthroughnationalinventoriestotheglobalmethanecycle.AgriculturalandForestMeteorology,142(2‐4):120‐132.

Lassey,K.R.,C.S.Pinares‐Patiño,R.J.Martin,G.Molano,etal.2011.EntericmethaneemissionratesdeterminedbytheSF6tracertechnique:Temporalpatternsandaveragingperiods.AnimalFeedScienceandTechnology,166–167(0):183‐191.

Laubach,J.,andF.M.Kelliher.2005.Measuringmethaneemissionratesofadairycowherd(II):resultsfromabackward‐Lagrangianstochasticmodel.AgriculturalandForestMeteorology,129(3‐4):137‐150.

Laubach,J.,F.M.Kelliher,T.W.Knight,H.Clark,etal.2008.Methaneemissionsfrombeefcattle—acomparisonofpaddock‐andanimal‐scalemeasurements.AustralianJournalofExperimentalAgriculture,48:132‐137.

Le,P.,A.Aarnink,A.Jongbloed,C.vanderPeetSchwering,etal.2008.Interactiveeffectsofdietarycrudeproteinandfermentablecarbohydratelevelsonodourfrompigmanure.LivestockScience,114:48–61.

Le,P.D.,A.J.A.Aarnink,A.W.Jongbloed,C.M.C.vanderPeetSchwering,etal.2007.Effectsofcrystallineaminoacidsupplementationtothedietonodorfrompigmanure.JournalofAnimalScience,85(3):791‐801.

Lee,S.S.,J.‐T.Hsu,H.C.Mantovani,andJ.B.Russell.2002.TheeffectofbovicinHC5,abacteriocinfromStreptococcusbovisHC5,onruminalmethaneproductioninvitro1.FEMSMicrobiologyLetters,217(1):51‐55.

Legesse,G.,J.A.Small,S.L.Scott,G.H.Crow,etal.2011.Predictionsofentericmethaneemissionsforvarioussummerpastureandwinterfeedingstrategiesforcowcalfproduction.AnimalFeedScienceandTechnology,166‐167(0):678‐687.

Lenis,N.1993.Lowernitrogenexcretioninpighusbandrybyfeeding:Currentandfuturepossibilities.ProceedingsoftheFirstInter.Symp.NitrogenFlowinPigProductionandEnvironmentalConsequences.,Pudoc,Wageningen,Netherlands.

Leytem,A.B.,R.S.Dungan,D.L.Bjorneberg,andA.C.Koehn.2011.EmissionsofAmmonia,Methane,CarbonDioxide,andNitrousOxidefromDairyCattleHousingandManureManagementSystems.JournalofEnvironmentalQuality,40(5):1383‐1394.

Leytem,A.B.,R.S.Dungan,D.L.Bjorneberg,andA.C.Koehn.2013.Greenhousegasandammoniaemissionsfromanopen‐freestalldairyinsouthernIdaho.JournalofEnvironmentalQuality,42:10‐20.

Li,L.,J.Cyriac,K.F.Knowlton,L.C.Marr,etal.2009.Effectsofreducingdietarynitrogenonammoniaemissionsfrommanureonthefloorofanaturallyventilatedfreestalldairybarnatlow(0‐20C)temperatures.JournalofEnvironmentalQuality,38:2172‐2181.

Li,W.,W.J.Powers,D.Karcher,C.R.Angel,etal.2010.EffectofDDGSandmineralsourcesonairemissionsfromlayinghens.PoultryScience,89(E‐Suppl.1).

Li,W.,W.Powers,andG.M.Hill.2011.FeedingDDGStoswineandresultingimpactonairemissions.JournalofAnimalScience,89:3286‐3299.

Liebig,M.A.,J.R.Gross,S.L.Kronberg,R.L.Phillips,etal.2010.Grazingmanagementcontributionstonetglobalwarmingpotential:Along‐termevaluationintheNorthernGreatPlains.JournalofEnvironmentalQuality,39:799‐809.

Little,S.,J.Linderman,K.MacLean,andH.Janzen.2008.Holos–atooltoestimateandreducegreenhousegasesfromfarms.Methodologyandalgorithmsforversions1.1x:AgricultureandAgri‐FoodCanada.http://www4.agr.gc.ca/AAFC‐AAC/display‐afficher.do?id=1226606460726&lang=eng#s1.


5-150

Liu,Z.,H.Liu,andW.Powers.2011a.Meta‐analysisofGreenhouseGasEmissionsfromswineoperations.ProceedingsoftheASABEAnnualMeeting,August7‐10,2011,Louisville,KY.

Liu,Z.,W.Powers,D.Karcher,R.Angel,etal.2011b.Effectofaminoacidformulationandsupplementationonnutrientmassbalanceinturkeys.PoultryScience,90(6):1153‐1161.

Liu,Z.,W.Powers,D.Karcher,R.Angel,etal.2011a.Effectofaminoacidformulationandsupplementationonairemissionsfromturkeys.Trans.ASABE,54:617‐628.

Locke,M.A.,M.A.Weaver,R.M.Zablotowicz,R.W.Steinriede,etal.2011.Constructedwetlandsasacomponentoftheagriculturallandscape:Mitigationofherbicidesinsimulatedrunofffromuplanddrainageareas.Chemosphere.

Loh,Z.,D.Chen,M.Bai,T.Naylor,etal.2008.MeasurementofgreenhousegasemissionsfromAustralianfeedlotbeefproductionusingopen‐pathspectroscopyandatmosphericdispersionmodeling.AustralianJournalofExperimentalAgriculture,48:244‐247.

Lovanh,N.,J.Warren,andK.Sistani.2010.Determinationofammoniaandgreenhousegasemissionsfromlandapplicationofswineslurry:Acomparisonofthreeapplicationmethods.BioresourceTechnology,101(6):1662‐1667.

Lovett,D.,S.Lovell,L.Stack,J.Callan,etal.2003.Effectofforage/concentrateratioanddietarycoconutoillevelonmethaneoutputandperformanceoffinishingbeefheifers.LivestockProductionScience,84(2):135‐146.

Lu,S.Y.,P.Y.Zhang,andW.H.Cui.2010.Impactofplantharvestingonnitrogenandphosphorusremovalinconstructedwetlandstreatingagriculturalregionwastewater.InternationalJournalofEnvironmentandPollution,43(4):339‐353.

Luo,J.,andS.Saggar.2008.Nitrousoxideandmethaneemissionsfromadairyfarmstand‐offpad.AustralianJournalofExperimentalAgriculture,48:179‐182.

Lupo,C.D.,D.E.Clay,J.L.Benning,andJ.J.Stone.2013.Life‐CycleAssessmentoftheBeefCattleProductionSystemfortheNorthernGreatPlains,USA.JournalofEnvironmentalQuality,42(5):1386‐1394.

Malone,R.W.,L.Ma,P.Heilman,D.L.Karlen,etal.2007.SimulatedNmanagementeffectsoncornyieldandtile‐drainagenitrateloss.Geoderma,140(3):272‐283.

Maltais‐Landry,G.,R.Maranger,J.Brisson,andF.Chazarenc.2009.Greenhousegasproductionandefficiencyofplantedandartificiallyaeratedconstructedwetlands.EnvironmentalPollution,157(3):748‐754.

Mander,U.,K.Lohmus,S.Teiter,K.Nurk,etal.2005a.Gaseousfluxesfromsubsurfaceflowconstructedwetlandsforwastewatertreatment.JournalofEnvironmentalScienceandHealth‐PartAToxic/HazardousSubstancesandEnvironmentalEngineering,40(6‐7):1215‐1226.

Mander,U.,S.Teiter,andJ.Augustin.2005b.Emissionofgreenhousegasesfromconstructedwetlandsforwastewatertreatmentandfromriparianbufferzones.

Martin,C.,D.P.Morgavi,andM.Doreau.2010.Methanemitigationinruminants:frommicrobetothefarmscale.Animal,4(03):351‐365.

McGinn,S.M.,H.H.Janzen,andT.Coates.2003.AtmosphericAmmonia,VolatileFattyAcids,andOtherOdorantsnearBeefFeedlots.JournalofEnvironmentalQuality,32(4):1173‐1182.

McGinn,S.M.,K.A.Beauchemin,T.Coates,andD.Colombatto.2004.Methaneemissionsfrombeefcattle:Effectsofmonensin,sunfloweroil,enzymes,yeast,andfumaricacid.JournalofAnimalScience,82(11):3346‐3356.

McGinn,S.M.,K.A.Beauchemin,A.D.Iwaasa,andT.McAllister.2006.Assessmentofthsulfurhexafluoride(SF6)tracertechniqueformeasuringentericmethaneemissionsfromcatttle.JournalofEnvironmentalQuality,35:1686‐1691.

McGinn,S.M.,D.Chen,Z.Loh,J.Hill,etal.2008.MethaneemissionsfromfeedlotcattleinAustraliaandCanada.AustralianJournalofExperimentalAgriculture,48:183‐185.


5-151

McGinn,S.M.,Y.‐H.Chung,K.A.Beauchemin,A.D.Iwaasa,etal.2009.Useofcorndistillers’driedgrainstoreduceentericmethanelossfrombeefcattle.CanadianJournalofAnimalScience,89(3):409‐413.

McGinn,S.M.,D.Turner,N.Tomkins,E.Charmley,etal.2011.MethaneEmissionsfromGrazingCattleUsingPoint‐SourceDispersion.JournalofEnvironmentalQuality,40(1):22‐27.

Michal,J.J.,E.Allwine,S.Spogen,S.Pressley,etal.2010.Nitrousoxideandmethaneemissionsformalargebeeffeedlot.ProceedingsoftheGreenhouseGasinAnimalAgricultureConference,Banff,Alberta,Canada.

Milano,G.,andH.Clark.2008.Theeffectoflevelofintakeandforagequalityonmethaneproductionbysheep.AustralianJournalofExperimentalAgriculture,48:219‐222.

Miles,D.,P.Owens,andD.Rowe.2006.Spatialvariabilityoflittergaseousfluxwithinacommercialbroilerhouse:ammonia,nitrousoxide,carbondioxide,andmethane.PoultryScience,85(2):167‐172.

Miles,D.M.,D.E.Rowe,andP.R.Owens.2008.Winterbroilerlittergasesandnitrogencompounds:Temporalandspatialtrends.AtmosphericEnvironment,42(14):3351‐3363.

Miles,D.M.,D.E.Rowe,andT.C.Cathcart.2011.Litterammoniageneration:Moisturecontentandorganicversusinorganicbeddingmaterials.PoultryScience,90(6):1162‐1169.

Mills,J.A.,J.Dijkstra,A.Bannink,S.B.Cammell,etal.2001.Amechanisticmodelofwhole‐tractdigestionandmethanogenesisinthelactatingdairycow:modeldevelopment,evaluation,andapplication.JournalofAnimalScience,79(6):1584‐1597.

Mills,J.A.N.,E.Kebreab,C.M.Yates,L.A.Crompton,etal.2003.Alternativeapproachestopredictingmethaneemissionsfromdairycows.JournalofAnimalScience,81(12):3141‐3150.

Miner,J.R.1975.Evaluationofalternativeapproachestocontrolodorsfromanimalfeedlots.Moscow,ID:IdahoResearchFoundation.

Misselbrook,T.,D.Chadwick,B.Pain,andD.Headon.1998.DietarymanipulationasameansofdecreasingNlossesandmethaneemissionsandimprovingherbageNuptakefollowingapplicationofpigslurrytograssland.TheJournalofAgriculturalScience,130:183‐191.

Misselbrook,T.H.,J.M.Powell,G.A.Broderick,andJ.H.Grabber.2005.DietaryManipulationinDairyCattle:LaboratoryExperimentstoAssesstheInfluenceonAmmoniaEmissions.JournalofDairyScience,88(5):1765‐1777.

Moe,P.W.,andH.F.Tyrrell.1979.MethaneProductioninDairyCows.JournalofDairyScience,62(10):1583‐1586.

Møller,H.B.,S.G.Sommer,andB.K.Ahring.2004.Methaneproductivityofmanure,strawandsolidfractionsofmanure.BiomassandBioenergy,26(5):485‐495.

Møller,H.G.,I.Lund,andS.G.Sommer.2000.Solid‐liquidseparationoflivestockslurry:efficiencyandcost.BioresourceTechnology,74(2000):223‐229.

Monteny,G.‐J.,A.Bannink,andD.Chadwick.2006.Greenhousegasabatementstrategiesforanimalhusbandry.Agriculture,Ecosystems&Environment,112(2‐3):163‐170.

Montgomery,J.L.,C.R.Krehbiel,J.J.Cranston,D.A.Yates,etal.2009.Dietaryzilpaterolhydrochloride.I.Feedlotperformanceandcarcasstraitsofsteersandheifers.JournalofAnimalScience,87:1374‐1383.

Moore,P.A.,T.C.Daniel,andD.R.Edwards.2000.Reducingphosphorusrunoffandinhibitingammonialossfrompoultrymanurewithaluminumsulfate.JournalofEnvironmentalQuality,29(37‐49).

Moore,P.A.,D.Miles,R.Burns,D.Pote,etal.2011.Ammoniaemissionfactorsfrombroilerlitterinbarns,instorage,andafterlandapplication.JournalofEnvironmentalQuality,40:1395‐1404.

Moore,P.A.2013.TreatingpoultrylitterwithaluminumSulfate(Alum):EmissionManagementPracticesFactSheet.USDALivestockGRACEnet,U.S.DepartmentofAgriculture.


5-152

Moore,P.A.J.,D.Miles,R.Burns,D.Pote,etal.2010.Ammoniaemissionfactorsfromboilerlitterinbarns,instorage,andafterlandapplication.JournalofEnvironmentalQuality,40:1395‐1404.

Moore,S.S.,F.D.Mujibi,andE.L.Sherman.2009.Molecularbasisforresidualfeedintakeinbeefcattle.JournalofAnimalScience,87(14suppl):E41‐E47.

Morgavi,D.P.,E.Forano,C.Martin,andC.J.Newbold.2010.Microbialecosystemandmethanogenesisinruminants.Animal,4(SpecialIssue07):1024‐1036.

Münger,A.,andM.Kreuzer.2008.Absenceofpersistentmethaneemissiondifferencesinthreebreedsofdairycows.AustralianJournalofExperimentalAgriculture,48:77‐82.

Murphy,M.R.,R.L.Baldwin,andL.J.Koong.1982.EstimationofStoichiometricParametersforRumenFermentationofRoughageandConcentrateDiets.JournalofAnimalScience,55(2):411‐421.

Mustafa,A.,M.Scholz,R.Harrington,andP.Carroll.2009.Long‐termperformanceofarepresentativeintegratedconstructedwetlandtreatingfarmyardrunoff.EcologicalEngineering,35(5):779‐790.

Ndegwa,P.,A.Hristov,J.Arogo,andR.Sheffield.2008.AReviewofAmmoniaEmissionTechniquesforConcentratedAnimalfeedingOperations.BiosystemsEngineering,100:453‐469.

NewZealandMinistryfortheEnvironment.2010.ProjectedbalanceofemissionsunitsduringthefirstcommitmentperiodoftheKyotoProtocol.http://www.mfe.govt.nz/publications/climate/projected‐balance‐units‐may05/html/page10.html.

NGGIC.1996.AustralianMethodologyfortheEstimationofGreenhouseGasEmissionsandSinks.Agriculture,WorkbookforLivestock,Workbook6.1,Revision1.Canberra,Australia:NationalGreenhouseInventoryCommittee,DepartmentoftheEnvironment,Sport,andTerritories.

Ngwabie,N.M.,K.H.Jeppsson,S.Nimmermark,C.Swensson,etal.2009.Multi‐locationmeasurementsofgreenhousegasesandemissionratesofmethaneandammoniafromanaturally‐ventilatedbarnfordairycows.BiosystemsEngineering,103(1):68‐77.

Ni,J.Q.1999.Mechanisticmodelsofammoniareleasefromliquidmanure:areview.JournalofAgriculturalEngineeringResearch,72(1):1‐17.

Nielsen,D.A.,L.P.Nielsen,A.Schramm,andN.P.Revsbech.2010.OxygenDistributionandPotentialAmmoniaOxidationinFloating,LiquidManureCrusts.JournalofEnvironmentalQuality,39(5):1813‐1820.

Nkrumah,J.D.,E.K.Okine,G.W.Mathison,K.Schmid,etal.2006.Relationshipsoffeedlotfeedefficiency,performance,andfeedingbehaviorwithmetabolicrate,methaneproduction,andenergypartitioninginbeefcattle.JournalofAnimalScience,84(1):145‐153.

Nozière,P.,I.Ortigues‐Marty,C.Loncke,andD.Sauvant.2010.Carbohydratequantitativedigestionandabsorptioninruminants:fromfeedstarchandfibretonutrientsavailablefortissues.Animal,4(SpecialIssue07):1057‐1074.

NRC.1989.NutrientRequirementsofDairyCattle.Washington,DC:NationalResearchCouncil,NationalAcademyofScience,.

NRC.2000.NutrientRequirementsofBeefCattleUpdate2000.Washington,DC:Natl.Acad.Press.Ocfemia,K.S.,Y.Zhang,andT.Funk.2006.Hydrothermalprocessingofswinemanuretooilusinga

continuousreactorsystem:Effectsofoperatingparametersonoilyieldandquality.TransactionsoftheASABE,49(6):1897‐1904.

Odongo,N.E.,R.Bagg,G.Vessie,P.Dick,etal.2007.Long‐TermEffectsofFeedingMonensinonMethaneProductioninLactatingDairyCows.JournalofDairyScience,90(4):1781‐1788.

Olson,K.C.,J.A.Walker,C.A.Stonecipher,B.R.Bowman,etal.2000.Effectofgrassspeciesonmethaneemissionsbybeefcattle.Soc.RangeManage.AnnualMeeting.


5-153

Ominski,K.H.,D.A.Boadi,andK.M.Wittenberg.2006.Entericmethaneemissionsfrombackgroundedcattleconsumingall‐foragediets.CanadianJournalofAnimalScience,86(3):393‐400.

Outor‐Monteiro,D.,V.M.CarvalhoPinheiro,L.J.MedeirosMourão,andM.A.MachadoRodrigues.2010.Strategiesformitigationofnitrogenenvironmentalimpactfromswineproduction.R.Bras.Zootec,39:317‐325.

Owens,F.N.,D.S.Secrist,W.J.Hill,andD.R.Gill.1997.Theeffectofgrainsourceandgrainprocessingonperformanceoffeedlotcattle:Areview.75(868‐879).

Panetta,D.M.,W.J.Powers,H.Xin,B.Kerr,etal.2006.Nitrogenexcretionandammoniaemissionsfrompigsfedmodifieddiets.JournalofEnvironmentalQuality,35(4):1297‐1308.

Parker,D.B.,E.A.Caraway,M.B.Rhoades,N.A.Cole,etal.2010.EffectofwindtunnelairvelocityonVOCfluxfromstandardsolutionsandCAFOmanure/wastewater.Trans.ASABE,53:831‐845.

Paul,J.W.,N.E.Dinn,T.Kannangara,andL.J.Fisher.1998.ProteinContentinDairyCattleDietsAffectsAmmoniaLossesandFertilizerNitrogenValue.JournalofEnvironmentalQuality,27(3):528‐534.

Paul,R.,andW.W.Watson.1966.THERMALDIFFUSIONANDSELF‐DIFFUSIONINAMMONIA.JournalofChemicalPhysics,45(7):2675‐&.

Pavao‐Zuckerman,M.A.,J.C.Waller,T.Ingle,andH.A.Fribourg.1999.MethaneEmissionsofBeefCattleGrazingTallFescuePasturesatThreeLevelsofEndophyteInfestation.JournalofEnvironmentalQuality,28(6):1963‐1969.

Pelletier,N.,R.Pirog,andR.Rasmussen.2010.ComparativelifecycleenvironmentalimpactsofthreebeefproductionstrategiesintheUpperMidwesternUnitedStates.AgriculturalSystems,103:380‐389.

Peters,G.M.,H.V.Rowley,S.Wiedemann,R.Tucker,etal.2010.RedmeatproductioninAustralia:Lifecycleassessmentandcomparisonwithoverseasstudies.EnvironmentalScienceandTechnology,44:1327‐1332.

Petersen,S.O.,andS.G.Sommer.2011.Ammoniaandnitrousoxideinteractions:Rolesofmanureorganicmattermanagement.AnimalFeedScienceandTechnology,166–167:503‐513.

Phetteplace,H.,D.Johnson,andA.Seidl.2001.GreenhousegasemissionsfromsimulatedbeefanddairylivestocksystemsintheUnitedStates.NutrientCyclinginAgroecosystems,60(1):99‐102.

Philippe,F.‐X.,M.Laitat,B.Canart,M.Vandenheede,etal.2007.Comparisonofammoniaandgreenhousegasemissionsduringthefatteningofpigs,kepteitheronfullyslattedfloororondeeplitter.LivestockScience,111:144‐152.

Picek,T.,H.Čížková,andJ.Dušek.2007.Greenhousegasemissionsfromaconstructedwetland‐Plantsasimportantsourcesofcarbon.EcologicalEngineering,31(2):98‐106.

Pinares‐Patiño,C.S.,M.J.Ulyatt,G.C.Waghorn,K.R.Lassey,etal.2003.Methaneemissionbyalpacaandsheepfedonlucernehayorgrazedonpasturesofperennialryegrass/whitecloverorbirdsfoottrefoil.JournalofAgriculturalScience,140(02):215‐226.

Portejoie,S.,J.Dourmad,J.Martinez,andY.Lebreton.2004.Effectofloweringcrudeproteinonnitrogenexcretion,manurecompositionandammoniaemissionfromfatteningpigs..LivestockProd.Sci.,91:45‐55.

Pos,J.,R.Trapp,andM.Harvey.1984.PerformanceofaBrushedScreen/RollerPressManureSeparator,ASAEPaperNo.83‐4065.St.Joseph,MI:AmericanSocietyofAgriculturalEngineers.

Powell,J.M.,P.R.Cusick,T.H.Misselbrook,andB.J.Holmes.2007.Designandcalibrationofchambersformeasuringammoniaemissionsfromtie‐stalldairybarns.Trans.ASABE,49(4):1139‐1149.


5-154

Powell,J.M.,G.A.Broderick,andT.H.Misselbrook.2008.SeasonalDietAffectsAmmoniaEmissionsfromTie‐StallDairyBarns.JournalofDairyScience,91(2):857‐869.

Powell,J.M.,G.A.Broderick,J.H.Grabber,andU.C.Hymes‐Fecht.2009.Technicalnote:Effectsofforageprotein‐bindingpolyphenolsonchemistryofdairyexcreta.JournalofDairyScience,92(4):1765‐1769.

Powell,J.M.,M.J.Aguerre,andM.A.Wattiaux.2011.TanninExtractsAbateAmmoniaEmissionsfromSimulatedDairyBarnFloors.JournalofEnvironmentalQuality,40(3):907‐914.

Powers,W.,S.Zamzow,andB.Kerr.2007.Reducedcrudeproteineffectsonaerialemissionsfromswine.AppliedEngineeringinAgriculture,23:539‐546.

Powlson,D.S.,A.B.Riche,K.Coleman,M.J.Glendining,etal.2008.CarbonsequestrationinEuropeansoilsthroughstrawincorporation:Limitationsandalternatives.WasteManagement,28(4):741‐746.

Preston,R.L.2013.NutrientValuesfor300CattleFeeds.BeefMagazine.Radunz,A.2011.OptaflexxandZilmax:Betaagonists:Growthpromotingfeedadditivesforbeef

cattle:UniversityofWyomingExtensionReport.Raman,K.P.,W.P.Walawender,andL.T.Fan.1980.Gasificationoffeedlotmanureinafluidizedbed

reactor.Theeffectoftemperature.Industrial&EngineeringChemistryProcessDesignandDevelopment,19(4):623‐629.

Reynolds,C.K.,J.A.N.Mills,L.A.Crompton,D.I.Givens,etal.2010.Ruminantnutritionregimestoreducegreenhousegasemissionsindairycows.InEnergyandproteinmetabolismandnutrition,G.M.Crovetto(ed.):EEAP

Ro,K.S.,K.Cantrell,D.Elliott,andP.G.Hunt.2007.Catalyticwetgasificationofmunicipalandanimalwastes.IndustrialandEngineeringChemistryResearch,46(26):8839‐8845.

Ro,K.S.,K.B.Cantrell,P.G.Hunt,T.F.Ducey,etal.2009.Thermochemicalconversionoflivestockwastes:Carbonizationofswinesolids.BioresourceTechnology,100(22):5466‐5471.

Ro,K.S.,K.B.Cantrell,andP.G.Hunt.2010.High‐temperaturepyrolysisofblendedanimalmanuresforproducingrenewableenergyandvalue‐addedbiochar.IndustrialandEngineeringChemistryResearch,49(20):10125‐10131.

Roberts,S.A.,H.Xin,B.J.Kerr,J.R.Russell,etal.2007.EffectsofDietaryFiberandReducedCrudeProteinonAmmoniaEmissionfromLaying‐HenManure.PoultryScience,86(8):1625‐1632.

Robinson,B.,andE.Okine.2001.Feedintakeinfeedlotcattle.AlbertaFeedlotManagementGuide,2ndEdition.http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/beef4873.

Rotz,C.A.2004.Managementtoreducenitrogenlossesinanimalproduction.JournalofAnimalScience,82(13suppl):E119‐E137.

Rotz,C.A.,D.R.Buckmaster,andJ.W.Comerford.2005.Abeefherdmodelforsimulatingfeedintake,animalperformance,andmanureexcretioninfarmsystems.JournalofAnimalScience,83(1):231‐242.

Rotz,C.A.,D.S.Chianese,F.Montes,andS.Hafner.2011a.Dairygasemissionsmodel:Referencemanual:U.S.DepartmentofAgriculture,AgriculturalResearchService.

Rotz,C.A.,M.S.Corson,D.S.Chianese,F.Montes,etal.2011b.Integratedfarmsystemmodel:ReferenceManual.UniversityPark,PA:U.S.DepartmentofAgriculture,AgriculturalResearchService.http://ars.usda.gov/SP2UserFiles/Place/19020000/ifsmreference.pdf.

Saggar,S.,C.B.Hedley,D.L.Giltrap,andS.M.Lambie.2007.Measuredandmodelledestimatesofnitrousoxideemissionandmethaneconsumptionfromasheep‐grazedpasture.Agriculture,Ecosystems&Environment,122(3):357‐365.

Saha,C.K.,C.Ammon,W.Berg,M.Fiedler,etal.2014.Seasonalanddielvariationsofammoniaandmethaneemissionsfromanaturallyventilateddairybuildingandtheassociatedfactorsinfluencingemissions.ScienceoftheTotalEnvironment,468:469‐462.


5-155

Samer,M.,M.Fiedler,H.J.Müller,M.Gläser,etal.2011.Wintermeasurementsofairexchangeratesusingtracergastechniqueandquantificationofgaseousemissionsfromanaturallyventilateddairybarn.AppliedEngineeringinAgriculture.

Seo,D.C.,andR.D.DeLaune.2010.Fungalandbacterialmediateddenitrificationinwetlands:Influenceofsedimentredoxcondition.WaterResearch,44(8):2441‐2450.

Shiflett,J.S.2011.SheepandLambIndustryEconomicImpactAnalysis:AmericanSheepIndustryAssociationhttp://www.sheepusa.org/user_files/file_865.pdf

Shutt,J.W.,R.K.White,E.P.Taiganides,andC.R.Mote.1975.EvaluationofSolidsSeparationDevices.Proceedingsofthe3rdInternationalSymposiumonLivestockWastes,Urbana‐Champaign,IL,April21‐24,1975.

Sneath,R.W.,M.Shaw,andA.G.Williams.1988.Centrifugationforseparatingpiggeryslurry1.Theperformanceofadecantingcentrifuge.JournalofAgriculturalEngineeringResearch,39(3):181‐190.

Sommer,S.G.,S.O.Petersen,andH.B.Møller.2004.Algorithmsforcalculatingmethaneandnitrousoxideemissionsfrommanuremanagement.NutrientCyclinginAgroecosystems,69:143‐154.

Soosaar,K.,M.Maddison,andÜ.Mander.2009.Waterqualityandemissionratesofgreenhousegasesinatreatmentreedbed.

Søvik,A.K.,J.Augustin,K.Heikkinen,J.T.Huttunend,etal.2006.EmissionoftheGreenhouseGasesNitrousOxideandMethanefromConstructedWetlandsinEurope.JournalofEnvironmentalQuality,35(6):2360‐2373.

Spiehs,M.J.,B.L.Woodbury,B.E.Doran,R.A.Eigenberg,etal.2011.Environmentalconditionsindeep‐beddedmono‐slopefacilities:Adescriptivestudy.Trans.ASABE,54:663‐673.

Stackhouse‐Lawson,K.R.,C.A.Rotz,J.W.Oltjen,andF.M.Mitloehner.2012.CarbonfootprintandammoniaemissionsofCaliforniabeefproductionsystems.JournalofAnimalScience,90:4641‐4655.

Stackhouse,K.R.,C.A.Rotz,J.W.Oltjen,andF.M.Mitloehner.2012.Growthpromotingtechnologiesreducethecarbonfootprint,ammoniaemissions,andcostofCaliforniabeefproductionsystems.JournalofAnimalScience,90:4656‐4665.

Stein,O.R.,andP.B.Hook.2005.Temperature,plants,andoxygen:Howdoesseasonaffectconstructedwetlandperformance?JournalofEnvironmentalScienceandHealth‐PartAToxic/HazardousSubstancesandEnvironmentalEngineering,40(6‐7):1331‐1342.

Stein,O.R.,J.A.Biederman,P.B.Hook,andW.C.Allen.2006.Plantspeciesandtemperatureeffectsonthek‐C*first‐ordermodelforCODremovalinbatch‐loadedSSFwetlands.EcologicalEngineering,26(2):100‐112.

Stein,O.R.,B.W.Towler,P.B.Hook,andJ.A.Biederman.2007a.Onfittingthek‐C*firstordermodeltobatchloadedsub‐surfacetreatmentwetlands.WaterScienceandTechnology,56(3):93‐99.

Stein,O.R.,B.W.Towler,P.B.Hook,andJ.A.Biederman.2007b.Onfittingthek‐C*firstordermodeltobatchloadedsub‐surfacetreatmentwetlands.

Stone,K.C.,P.G.Hunt,A.A.Szogi,F.J.Humenik,etal.2002.Constructedwetlanddesignandperformanceforswinelagoonwastewatertreatment.TransactionsoftheAmericanSocietyofAgriculturalEngineers,45(3):723‐730.

Stone,K.C.,M.E.Poach,P.G.Hunt,andG.B.Reddy.2004.Marsh‐pond‐marshconstructedwetlanddesignanalysisforswinelagoonwastewatertreatment.EcologicalEngineering,23(2):127‐133.

Stone,K.C.,P.G.Hunt,K.B.Cantrell,andK.S.Ro.2010.Thepotentialimpactsofbiomassfeedstockproductiononwaterresourceavailability.BioresourceTechnology,101(6):2014‐2025.

Sun,H.,S.L.Trabue,K.Scoggin,W.A.Jackson,etal.2008.Alcohol,VolatileFattyAcid,Phenol,andMethaneEmissionsfromDairyCowsandFreshManure.JournalofEnvironmentalQuality,37(2):615‐622.


5-156

Sutton,A.,K.Kephardt,J.Patterson,R.Mumma,etal.1996.Manipulatingswinedietstoreduceammoniaandodoremissions.Proceedingsofthe1stInternationalConferenceonAirPollutionfromAgriculturalOperations,KansasCity,MO.

Sveinbjornsson,P.,P.Huhtanen,andJ.Uden.2006.TheNordicdairycowmodel,Karoline–developmentofvolatilefattyacidsubmodel.InNutrientDigestionandUtilizationinFarmAnimals:ModelingApproach,E.Kebreab,J.Dijkstra,A.Bannink,W.J.J.GerritsandJ.France(eds.).Wallingford,UK:CABPublishing.

Sweeten,J.2004.AirQuality:Odor,Dust,andGaseousEmissionsfromConcentratedAnimalFeedingOperationsintheSouthernGreatPlains,ProjectNo.2003‐34466‐13146/CSREESProject#TS‐2003‐06007:U.S.DepartmentofAgriculture,CSREESSpecialResearchGrantsProgram

Szanto,G.L.,H.V.M.Hamelers,W.H.Rulkens,andA.H.M.BVeeken.2006.NH3,N2OandCH4emissionsduringpassivelyaeratedcompostingofstraw‐richpigmanure.BioresourceTechnology,98:2659‐2670.

Tanner,C.C.,D.D.Adams,andM.T.Downes.1997.Methaneemissionsfromconstructedwetlandstreatingagriculturalwastewaters.JournalofEnvironmentalQuality,26(4):1056‐1062.

Tanner,C.C.,andT.R.Headley.2011.Componentsoffloatingemergentmacrophytetreatmentwetlandsinfluencingremovalofstormwaterpollutants.EcologicalEngineering,37(3):474‐486.

Tanner,C.C.,andJ.P.S.Sukias.2011.Multiyearnutrientremovalperformanceofthreeconstructedwetlandsinterceptingtiledrainflowsfromgrazedpastures.JournalofEnvironmentalQuality,40(2):620‐633.

Taylor,C.R.,P.B.Hook,O.R.Stein,andC.A.Zabinski.2010.Seasonaleffectsof19plantspeciesonCODremovalinsubsurfacetreatmentwetlandmicrocosms.EcologicalEngineering.

Tedeschi,L.O.,D.G.Fox,andT.P.Tylutki.2003.PotentialEnvironmentalBenefitsofIonophoresinRuminantDiets.JournalofEnvironmentalQuality,32(5):1591‐1602.

Teiter,S.,andU.Mander.2005.EmissionofN2O,N2,CH4,andCO2fromconstructedwetlandsforwastewatertreatmentandfromriparianbufferzones.EcologicalEngineering,25(5):528‐541.

Todd,R.W.,N.A.Cole,L.A.Harper,T.K.Flesch,etal.2005.Ammoniaandgaseousnitrogenemissionsfromacommercialbeefcattlefeedyardestimatedusingtheflux‐gradientmethodandN/Pratioanalysis.ProceedingsoftheStateoftheScience:Animalmanureandwastemanagement,Jan5‐7,2005,NationalCenterformanureandWasteManagement,SanAntonio,TX.

Todd,R.W.,N.A.Cole,H.M.Waldrip,andR.M.Aiken.2013.Arrheniusequationformodelingfeedyardammoniaemissionusingtemperatureanddietcrudeprotein.JournalofEnvironmentalQuality,42:666‐671.

Todd,R.W.,M.Altman,N.A.Cole,andH.M.Waldrip.2014a.MethaneemissiosnsfromabeefcattlefeedyardduringwinterandsummerontheSouthernHighPlainsofTexas.JournalofEnvironmentalQuality(inpress).

Todd,R.W.,H.M.Waldrip,M.Altman,andN.A.Cole.2014b.Methaneemissionsfromabeefcattlefeedyard:measurementsandmodels.ProceedingsoftheAmericanMeteorologicalSociety's31stConferenceonAgriculturalandForestMeteolorology,May12‐15,2014,Portland,OR.

Tomkins,N.W.,andR.A.Hunter.2004.Methanemitigationinbeefcattleusingapatentedanti‐methanogen.Proceedingsofthe2ndJointAustraliaandNewZealandForumonNon‐CO2GreenhouseGasEmissionsfromAgriculture,October2003,LancemoreHill,Canberra.

Tomkins,N.W.,S.M.Colegate,andR.A.Hunter.2009.Abromochloromethaneformulationreducesentericmethanogenesisincattlefedgrain‐baseddiets.AnimalProductionScience,49(12):1053‐1058.

Tomkins,N.W.,S.M.McGinn,D.A.Turner,andE.Charmley.2011.Comparisonofopen‐circuitrespirationchamberswithamicrometeorologicalmethodfordeterminingmethane


5-157

emissionsfrombeefcattlegrazingatropicalpasture.AnimalFeedScienceandTechnology,166‐167(0):240‐247.

Towler,B.W.,J.E.Cahoon,andO.R.Stein.2004.Evapotranspirationcropcoefficientsforcattailandbulrush.JournalofHydrologicEngineering,9(3):235‐239.

Trei,J.E.,G.C.Scott,andR.C.Parish.1972.InfluenceofMethaneInhibitiononEnergeticEfficiencyofLambs.JournalofAnimalScience,34(3):510‐515.

U.S.EPA.2011.U.S.GHGInventory1990‐2009:U.S.EnvrionmentalProtectionAgency.http://www.epa.gov/climatechange/emissions/downloads11/US‐GHG‐Inventory‐2011‐Chapter‐6‐Agriculture.pdf.

U.S.EPA.2013.InventoryofU.S.greenhousegasemissionsandsinks:1990‐2011.Washington,D.C.:EnvironmentalProtectionAgency.

Ungerfeld,E.M.,R.A.Kohn,R.J.Wallace,andC.J.Newbold.2007.Ameta‐analysisoffumarateeffectsonmethaneproductioninruminalbatchcultures.JournalofAnimalScience,85(10):2556‐2563.

USDA.2004a.Dairy2002.NutrientManagementandtheU.S.DairyIndustryin2002.Washington,DC:USDAAnimalandPlantHealthInspectionService.http://nahms.aphis.usda.gov/dairy/dairy02/Dairy02Nutrient_mgmt_rept.pdf.

USDA.2004b.USDAAgricultureandForestryGreenhouseGasInventory:1990‐2001.Washington,DC:U.S.DepartmentofAgriculture.http://www.usda.gov/oce/climate_change/ghg_inventory.htm.

USDA.2010.Beef2007‐08,PartV:ReferenceofBeefCow‐calfmanagementpracticesintheUnitedStates,2007‐2008.FortCollins,CO:USDA‐APHIS‐VS,CEAH.

USDANASS.2011.ChartsandMaps‐SheepandLamb:U.S.DepartmentofAgriculture,NationalAgriculturalStatisticsService.http://www.nass.usda.gov/Charts_and_Maps/Sheep_and_Lambs/index.asp.

USDANASS.2012.QuickStats:AgriculturalStatisticsDatabase.Washington,DC:U.S.DepartmentofAgriculture,NationalAgricultureStatisticsService.http://quickstats.nass.usda.gov/.

USDANRCS.2007.CompostingManure–What’sgoingoninthedark?,May2007,Number1.Washington,DC:U.S.DepartmentofAgriculture,NaturalResourcesConservationService.

VanKessel,J.A.S.,andJ.B.Russell.1996.TheeffectofpHonruminalmethanogenesis.FEMSMicrobiologyEcology,20(4):205‐210.

VanAmburgh,M.,L.Chase,T.Overton,E.Recktenwald,etal.2010.2010UpdatestotheCornellNetCarbohydrateandProteinSystemv6.1.ProceedingsoftheCornellNutritionConference.

VanderPol,K.J.,M.K.Luebbe,G.I.Crawford,G.E.Erickson,etal.2009.Performanceanddigestibilitycharacteristicsoffinishingdietscontainingdistillersgrains,compositesofcornprocessingcoproducts,orsupplementalcornoil.JournalofAnimalScience,87(2):639‐652.

VanderZaag,A.C.,R.J.Gordon,D.L.Burton,R.C.Jamieson,etal.2010.Greenhousegasemissionsfromsurfaceflowandsubsurfaceflowconstructedwetlandstreatingdairywastewater.JournalofEnvironmentalQuality,39(2):460‐471.

Vanotti,M.B.,andP.G.Hunt.1999.Solidsandnutrientremovalfromflushedswinemanureusingpolyacrylamides.TransactionsoftheAmericanSocietyofAgriculturalEngineers,42(6):1833‐1840.

Vanotti,M.B.,andP.G.Hunt.2000.Nitrificationtreatmentofswinewastewaterwithacclimatednitrifyingsludgeimmobilizedinpolymerpellets.TransactionsoftheASAE,43(2):405‐413.

Vanotti,M.B.,D.M.C.Rashash,andP.G.Hunt.2002.Solid‐liquidseparationofflushedswinemanurewithPAM:Effectofwastewaterstrength.TransactionsoftheAmericanSocietyofAgriculturalEngineers,45(6):1959‐1969.

Vanotti,M.B.,A.A.Szogi,andP.G.Hunt.2003.Extractionofsolublephosphorusfromswinewastewater.TransactionsoftheAmericanSocietyofAgriculturalEngineers,46(6):1665‐1674.


5-158

Vanotti,M.B.,P.D.Millner,P.G.Hunt,andA.Q.Ellison.2005.Removalofpathogenandindicatormicroorganismsfromliquidswinemanureinmulti‐stepbiologicalandchemicaltreatment.BioresourceTechnology,96(2):209‐214.

Vanotti,M.B.,A.A.Szogi,P.G.Hunt,P.D.Millner,etal.2007.DevelopmentofenvironmentallysuperiortreatmentsystemtoreplaceanaerobicswinelagoonsintheUSA.BioresourceTechnology,98(17):3184‐3194.

Vanotti,M.B.,andA.A.Szogi.2008.Waterqualityimprovementsofwastewaterfromconfinedanimalfeedingoperationsafteradvancedtreatment.JournalofEnvironmentalQuality,37(SUPPL.5):S86‐S96.

Vanotti,M.B.,A.A.Szogi,andC.A.Vives.2008.Greenhousegasemissionreductionandenvironmentalqualityimprovementfromimplementationofaerobicwastetreatmentsystemsinswinefarms.WasteManagement,28(4):759‐766.

Vanotti,M.B.,A.A.Szogi,P.D.Millner,andJ.H.Loughrin.2009.Developmentofasecond‐generationenvironmentallysuperiortechnologyfortreatmentofswinemanureintheUSA.BioresourceTechnology,100(22):5406‐5416.

Vanotti,M.B.,Millner,P.D.,Szogi,A.A.,Campbell,C.R.,Fetterman,L.M..2006.Aerobiccompostingofswinemanuresolidsmixedwithcottonginwaste.ASABEAnnualInternationalMeeting,Portland,Oregon.

Vasconcelos,J.T.,andM.L.Galyean.2007.Nutritionalrecommendationsoffeedlotconsultingnutritionists:The2007TexasTechUniversitysurvey.JournalofAnimalScience,85(10):2772‐2781.

Vasconcelos,J.T.,R.J.Rathmann,R.R.Reuter,J.Leibovish,etal.2008.Effectsofdurationofzilpaterolhydrochloridefeedinganddaysofthefinishingdietonfeedlotcattleperformanceandcarcasstraits.JournalofAnimalScience,86:2005‐2012.

Venterea,R.T.,K.A.Spokas,andJ.M.Baker.2009.AccuracyandPrecisionAnalysisofChamber‐BasedNitrousOxideGasFluxEstimates.SoilSci.Soc.Am.J.,73(4):1087‐1093.

Venterea,R.T.2010.SimplifiedMethodforQuantifyingTheoreticalUnderestimationofChamber‐BasedTraceGasFluxes.JournalofEnvironmentalQuality,39(1):126‐135.

Verge,X.P.C.,J.A.Dyer,R.L.Desjardins,andD.Worth.2008.GreenhousegasemissionsfromtheCanadianbeefindustry.AgriculturalSystems,98:126‐134.

Verge,X.P.X.,J.A.Dyer,R.L.Desjardins,andD.Worth.2009.GreenhousegasemissionsfromtheCanadianporkindustry.LivestockScience,121:92‐101.

Vogel,G.1995.Effectsofionophoresonfeedintakebyfeedlotcattle.ProceedingsoftheSymposiumonIntakeofFeedlotCattle,OklahomaStateUniv.July,1995.

Vymazal,J.2011.Enhancingecosystemservicesonthelandscapewithcreated,constructedandrestoredwetlands.EcologicalEngineering,37(1):1‐5.

Waghorn,G.C.,H.Clark,V.Taufa,andA.Cavanagh.2008.Monensincontrolled‐releasecapsulesformethanemitigationinpasture‐feddairycows.AustralianJournalofExperimentalAgriculture,48:65‐68.

Wagner,J.J.,T.E.Engle,andT.C.Bryant.2010.Theeffectofrumendegradableandrumenundegradableintakeproteinonfeedlotperformanceandcarcassmeritinheavyyearlingsteers.JournalofAnimalScience,88:1073‐1081.

Wang,L.,A.Shahbazi,andM.A.Hanna.2011.Characterizationofcornstover,distillergrainsandcattlemanureforthermochemicalconversion.BiomassandBioenergy,35(1):171‐178.

Wang,Y.,R.Inamori,H.Kong,K.Xu,etal.2008.Influenceofplantspeciesandwastewaterstrengthonconstructedwetlandmethaneemissionsandassociatedmicrobialpopulations.EcologicalEngineering,32(1):22‐29.

Westberg,H.,B.Lamb,K.A.Johnson,andM.Huyler.2001.InventoryofmethaneemissionsfromU.S.cattle.JournalofGeophysicalResearch,106(D12):12633‐12642.

White,F.1999.FluidMechanics.Boston,MA:McGraw‐HillScience/Engineering/Math.


5-159

Wileman,B.W.,D.U.Thomson,C.D.Reinhardt,andD.G.Renter.2009.Analysisofmoderntechnologiescommonlyusedinbeefcattleproduction:Conventionalbeefproductionversusnonconventionalproductionusingmeta‐analysis.JournalofAnimalScience,87:3418‐3426.

Wilkerson,V.A.,D.P.Casper,andD.R.Mertens.1995.ThePredictionofMethaneProductionofHolsteinCowsbySeveralEquations.JournalofDairyScience,78(11):2402‐2414.

Wolin,M.J.1960.ATheoreticalRumenFermentationBalance.JournalofDairyScience,43(10):1452‐1459.

Woodbury,B.L.,D.N.Miller,J.A.Nienaber,andR.A.Eigenberg.2001.Seasonalandspatialvariationsofdenitrifyingenzymeactivityinfeedlotsoil.Trans.ASABE,44:1635‐1642.

WRI.2009.DocumentationofEmissionsCalculationsforVersion1.2oftheManureandNutrientReductionEstimator(MANURE)Tool.Arlington,VA:ERT‐WinrockInternational.http://app6.erg.com/manure/docs/manure_calculations.pdf.

Wright,A.D.G.,P.Kennedy,C.J.O’Neill,A.F.Toovey,etal.2004.Reducingmethaneemissionsinsheepbyimmunizationagainstrumenmethanogens.Vaccine,22(29‐30):3976‐3985.

Wu‐Haan,W.,W.J.Powers,C.R.Angel,C.E.Hale,III,etal.2007a.NutrientDigestibilityandMassBalanceinLayingHensFedaCommercialorAcidifyingDiet.PoultryScience,86(4):684‐690.

Wu‐Haan,W.,W.J.Powers,C.R.Angel,C.E.Hale,III,etal.2007b.EffectofanAcidifyingDietCombinedwithZeoliteandSlightProteinReductiononAirEmissionsfromLayingHensofDifferentAges.PoultryScience,86(1):182‐190.

Wu,J.,J.Zhang,W.L.Jia,H.J.Xie,etal.2009.Nitrousoxidefluxesofconstructedwetlandstotreatsewagewastewater.HuanjingKexue/EnvironmentalScience,30(11):3146‐3151.

Xiu,S.,Y.Zhang,andA.Shahbazi.2009.Swinemanuresolidsseparationandthermochemicalconversiontoheavyoil.BioResources,4(2):458‐470.

Xiu,S.,A.Shahbazi,C.W.Wallace,L.Wang,etal.2011.Enhancedbio‐oilproductionfromswinemanureco‐liquefactionwithcrudeglycerol.EnergyConversionandManagement,52(2):1004‐1009.

Yan,T.,R.E.Agnew,F.J.Gordon,andM.G.Porter.2000.Predictionofmethaneenergyoutputindairyandbeefcattleofferedgrasssilage‐baseddiets.LivestockProductionScience,64(2‐3):253‐263.

Yan,T.,M.G.Porter,andC.S.Mayne.2009.Predictionofmethaneemissionfrombeefcattleusingdatameasuredinindirectopen‐circuitrespirationcalorimeters.Animal,3(10):1455‐1462.

Young,B.A.1981.Coldstressasitaffectsanimalproduction.JournalofAnimalScience,52:154‐163.Zhang,G.,J.S.Strøm,B.Li,H.B.Rom,etal.2005.Emissionofammoniaandothercontaminantgases

fromnaturallyventilateddairycattlebuildings.BiosystemsEngineering,92(3):355‐364.Zhu,G.,Z.Ma,Z.Gao,W.Ma,etal.2014.CharaterizingCH4andN2Oemissionsfromanintensive

dairyoperationinsummerandfallinChina.AtmosphericEnvironment,83:245‐253.Zhu,N.,P.An,B.Krishnakumar,L.Zhao,etal.2007.Effectofplantharvestonmethaneemission

fromtwoconstructedwetlandsdesignedforthetreatmentofwastewater.JournalofEnvironmentalManagement,85(4):936‐943.

Zinn,R.A.,andY.Shen.1996.Interactionofdietarycalciumandsupplementalfatondigestivefunctionandgrowthperformanceinfeedlotsteers.JournalofAnimalScience,74:2303‐2309.

Zinn,R.A.,andR.Barajas.1997.Influenceofflakedensityonthecomparativefeedingvalueofabarley‐cornblendforfeedlotcattle.JournalofAnimalScience,75(4):904‐909.


5-160

Thispageisintentionallyleftblank.

Chapter 5 Quantifying Greenhouse Gas Sources and …...Chapter 5: Quantifying Greenhouse Gas Sources...

Documents

Transcript of Chapter 5 Quantifying Greenhouse Gas Sources and …...Chapter 5: Quantifying Greenhouse Gas Sources...