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Dennis R. BuckmasterPurdue Agricultural & Biological Engineering
I’ll provide an internet URL for this entire presentation at the end.
Forage Systems OperationsStack
for storage
Wrap for storage
Pack into bag
Blow into silo
Pack into
bunker
Packaged transport
Bulk transport
Chop / roll process
Bale
Invert
Ted
Rake
Mow / condition
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What are the points (sources) of loss?� Pre-harvest� Machine
� Mower, rake, tedder, baler, chopper
� Respiration� Rain (leaching and longer respiration)� Storage
Types of Forage Loss� Dry Matter Loss … simply yield reduction� Quality Change … almost always drops (e.g., loss of leaves)
0
10
20
30
40
Dry
ma
tter
loss
(%
)
80 70 60 50 40 30 20 10
Average moisture content at harvest (%)
HARVEST LOSSSTORAGE LOSS
Directcut
silage(bunker,w/formic
acid)
Wiltedsilage
(bunker silo)
Haylage
(sealed silo)
Driedhay bales
Fieldcured hay
Rotz, 1991
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Presentation Outline
• Storage process determines suitable moisture range
Principles
• Mow• Swath manipulation• Bale• Store
• Inside• Not inside
Hay
• Mow• Harvest• Store
• Bunker• Bag• Bale• Tower
Silage
Forage Moisture Continuum12% 20% 30% 40% 70%
Safe
for
hay
Apply
preservative
or use a drier
Suitable for silage
Bunker
Tower
Baled
Silage
FIRE
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The principles• Low moisture so
respiration stops and bacteria, fungi, and yeasts cannot survive.
Hay
• Create anaerobic environment
• Reduce pH to a level where bacteria, fungi, and yeast growth is inhibited.
Silage
Basics of Silage Making
Pitt, 1990
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Basics of Silage Making
Pitt, 1990
Basics of Silage Making
Pitt, 1990
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Basics of Silage Making
Pitt, 1990
Typical Forage System Losses
Buckmaster, 1990
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Typical Forage System Losses
Buckmaster, 1990
Hay
Harvest
Storage
What can I do?
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Hay Harvest Losses
� Mowing-conditioning� 1-5%, mostly leaves� Conditioner design/setting has a large effect (trade-off
faster drying rate for more loss)� Flails cause more leaf loss in legumes
Hay Harvest Losses� Raking
� Loss increases as crop dries� Loss is higher with low yield or
after tedding� Loss can be up to 20%� Wheel & rotary rakes cause
more loss than parallel bar rakes� Best practice is to rake once, on
the day of baling
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Hay Harvest Losses� Baling
� Loss increases as crop dries� Loss occurs at the pickup
and in the chamber� Typical loss is 2 to 5%,
sometimes greater with low moisture or round balers in low yield situations (lots of tumbling)
� No large difference between in-line versus offset balers
Hay Harvest Losses� Respiration & Rain
� Highly variable� From 2 to 100% loss� Loss of most digestible plant
components
� Two strategies� Try to always avoid rain� Try to optimize annual harvest
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Hay Storage Losses
Huhnke
Quality deterioration can lead to 100% loss!
What can I do? … hay harvest� Time operations properly
� Mow considering crop and weather� Rake at 35-45% moisture or after rain� Ted immediately after mowing or after rain� Bale based on measured moisture content� Use preservative to avoid rain loss
� Have sufficient capacity (IN Hay Day 2008 topic)� Adjust machines appropriately� Operate at proper speeds� Take reasonable weather risks, then allocate ormarket
produced forages accordingly
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What can I do? … hay storage� Cover it� Keep it off of the ground
Buckmaster, 1993
Silage
Harvest
Storage
What can I do?
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Silage Harvest Losses� Mower-conditioner� Swath manipulation
� Rake� Merge
� Chop & transport
Silage Storage Losses� During filling� Long-term storage� During feedout
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Silage Storage … key factors� Proper moisture
� Too wet … effluent, clostridia risk� Too dry … lower density, inadequate moisture for
fermentation� Slow filling
� Longer respiration� Use of carbohydrate� Increase temperature
� Poor packing� Lower density (hence capacity)� More entrained air to consume� Less dense so infiltration is higher
What can I do? … silage & filling
BUNKER BAG TOWER BALED
Fill quickly Fill quickly Fill quickly Wrap soon
Fill in wedges or layers
Control stretch Even distribution in silo
Sufficient layers
Pack adequately Stack on end if atall
For all silage:•Proper moisture•Correct particle size•Adequate (high) density•Consider inoculants•Good initial quality
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125
188
250
313
375
20000
30000
40000
50000
60000
150 200 250 300 350 400 450
Min
imu
m b
un
ker
pac
ker
po
wer
(h
p)
Min
imu
m b
un
ker
pac
ker
wei
gh
t (l
b)
Harvester power (hp)
corn, 1 packer
haycrop, 1 packer
corn, 2 packers
haycrop, 2 packers
Adequate Bunker Packing
Buckmaster, 2009
At 160 lb/PTO hp
What can I do? ... silage longer term
BUNKER BAG TOWER BALED
Cover Keep seal, use proper tape
Maintain structure Keep seal, useproper tape
Contain effluent Adequate site Adequate site
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What can I do? ... silage feedout
BUNKER BAG TOWER BALED
Keep smooth face Control exposure Adequate removal rate
Open as you feed
Adequate removal rate
Feedout from a bunkerHolmes & Muck, 2000
>6 in/day removal rate>15 lb DM/ft3 density
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One more source of loss� Neither dry matter nor quality
� Of higher value than any forage you produce
� Let’s do our best to avoid …
Avoiding loss of life or limb� Shield disc mowers properly (knife tip speeds are
160 to 190 mph); always use a tractor with cab� Never stand behind conditioning rolls or flails� Remember that baler flywheels and hydraulic
accumulators store energy� Keep fingers out of moving knotters (even if they are
temporarily manually powered)� Do not ride the wagon when a bale thrower is used� Handle bales safely
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Avoiding loss of life or limb
� Keep equipment “harvest ready”� Keep guards & shields in proper order� Securely block hydraulically-raised
equipment before working around or under the machine
� Disengage power and shut off engine before unplugging
� Keep a fire extinguisher on all powered equipment
� No kids or other riders� Vent enclosed silage structures
A Useful Model -- IFSMThe Integrated Forage System Model
� Simulates multiple years, driven by historical weather data
� Growth models (grass, alfalfa, corn, small grains)� Harvest models (machinery, drying, operations, labor,
fuel, timing)� Storage models (hay, silage)� Feed utilization & conversion (beef, dairy, commercial
hay)
http://pswmru.arsup.psu.edu/software/ifsm.htm
The reference manual (free pdf) may provide you with
good insight regarding many forage processes.
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This presentation
For a limited time only …
http://cobweb.ecn.purdue.edu/~dbuckmas/icfs09/reducingloss.pdf
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