What Do We Know AboutStray Voltage?

Terms, Sources, Animal Research,Terms, Sources, Animal Research,Transients, High Frequency, Field

Studies, Earth Currents, EMF,

Douglas J. Reinemann, Ph.D.

University of Wisconsin Madison

Milking Research and Instruction Lab UW-MRIL

Don't Let Stray VoltageRuin Your Life

Hope

Trust

ResponsibilityResponsibility

Measure

ReasonTechnical RealityResearch

EmotionCompassion

Correct Farm WiringCorrect Distribution WiringUtility IsolatorEGS

Is it SafeIt is Technically EffectiveWill it help the cows

EGSIsolation TransformerGrounding Ring.

If You Think You Have AStray Voltage Problem

Watch the Cows.

Measure Voltage.

Find the Source.Find the Source.

Find the safest, simplest way to fixit.

If You Think You Have AStray Voltage Problem

If you Cannot Measure Cow ContactVoltage

Stray Voltage Can Be A ProblemStray Voltage Can Be A Problem

If its There You can Measure it andreduce it

Consider Other Sources ofProblems

Its Not Always the Problem

Learned Behavior Avoid Contact

Introduction to Stray Voltage

Prevent

How to:

DetectReduce

Stray Voltage

What Is Stray Voltage?A difference in voltage measuredbetween two surfaces that may becontacted simultaneously by ananimal (USDA, 1992).

It IS a Mild ShockIt IS a Mild Shockcaused by a contact voltage

It is NOT Electric/Magnetic Fields(EMF)

It is NOT "Ground CurrentsUnless they produce contact voltage

How Can Neutral Voltage BeReduced?

Reduce Resistance

Size of Conductor

Quality of jumpers and connectionsQuality of jumpers and connections

Number and quality of grounds

Reduce Current

Balance loads

Fix faults

The source of Stray Voltage is voltage developed by currentflowing on the resistance of the grounded neutral system

Animal Response to StrayVoltage

Avoidancebehavior

Milk production

Well documented

Documented onlyfor extremeexposure

Somatic cells

Reproduction

Milkout problems

exposure

Not documented

Not documented

Not documented

Reasonable Level

Zero tolerance is

Impossible

ExpensiveExpensive

May be Dangerous

Not warranted base on researchresults

Sensitivity to 50/60 Hz

Sensitivity to High Frequencies

Types of Voltage/Current

60 Hz voltage

Steady

Motor StartsMotor Starts

High Frequency Transients

Fencers, Trainers, Crowd Gates

Equipment Switching

Conclusions From USDA,1992 for 60 Hz Voltage.Perception begins 1 to 2 mA (0.5-2 V).

Cows become conditioned.Behavioral problems may persist afterBehavioral problems may persist afterstimulus is removed.

Keep Cow Contact Voltage < 2- 4 V.Consider cost of reducing voltage.

Economic/Non-Economic Effect.

Milking machine an unlikely pathway.

Wisconsin Rules andRegulations

PSCW stray voltage order.

The "level of concern" for livestock ismore than 2 milli-amps of steadystate, 60 Hz AC, RMS current inmore than 2 milli-amps of steadystate, 60 Hz AC, RMS current inanimal contact locations, measuredbetween two points that livestock maycontact simultaneously.

1 V = 2 mA x 500 Ohms.

Literature Review and Synthesis ofResearch Findings on the Impact ofStray Voltage on Farm Operations

Douglas J. Reinemann, Ph.d.

Professor of Biological SystemsEngineering

University of Wisconsin-Madison

1. Scope of this Report

Literature review

Pathways whereby stray voltage canaffect animals

Symptoms indicative of stray voltageSymptoms indicative of stray voltage

Minimum voltage (or current) level atwhich impacts can be expected.

Measures for mitigating stray voltage

Review of regulatory measures

Ways That Stray, or Tingle, VoltageCan Impact Farm Operations

Direct effects

Mild behavioral reactions = sensation

Involuntary muscle contraction = twitching

Intense behavioral responses = painIntense behavioral responses = pain

Severity depends onamount of electrical current (milliAmps) flowingthrough the animals body

Body pathway

Individual animal Sensitivity

Indirect effects

Animals avoiding certain exposure locationsReduced water intake if exposure is required foranimals to access watering devices,

Reduced feed intake if exposure is required foranimals to accesses feeding devices or locations.Reduced feed intake if exposure is required foranimals to accesses feeding devices or locations.

Difficulty of moving or handling animals in areasof voltage/current exposure

Release of stress hormones produced bycontact with painful stimuli

2. Overview of Electrical Exposure and thePhysiology of Animal Contact Voltage and

CurrentCurrent

Basic concepts of voltage, current, andresistance

Ohms law = relationship between

Voltage, Current and Resistance

If voltage (across animal contact points) isincreased, the current flowing through theanimal will increaseanimal will increase

If resistance (of contact points) isincreased, the current flowing through theanimal will decrease

1 milliAmp = 1/1000th of an amp

R

R

R

R

R

R

R

Elements of the Source Circuit

Vs = Voltage Source(I*R on neutral wire)

Rs = SourceResistance

Rp1 = Path

R

R

Rp1 = PathResistance 1

Rp2 = PathResistance 2

Voc = Open Circuitor Source Voltage

V

R

V

Elements of the AnimalCircuit

mA = currentthrough animal

Rc1 = contactResistance (Muzzle

R

Resistance (Muzzleor front hooves)

Ra = bodyResistance

Rc2 = contactresistance (allhooves or rearhooves)

R

VR

V

mA

V(source) R(Source) R(animal +contact)

AnimalContactvoltage

Animalcontactcurrent

1 volt 100 Ohms 500 Ohms 0.8 Volts 1.7

Importance of ProperCircuit Identification

1 volt 100 Ohms 500 Ohms 0.8 Volts 1.7milliAmps

1 volt 100 Ohms 1000 Ohms 0.9 Volts 0.9milliamps

1 volt 1000 Ohms 1000 Ohms 0.5 Volts 0.5milliamps

The Problem of Contact Resistance

The most variable part of the electrical circuit

Contact resistances will increase with:smaller contact surface area

reduced contact surface pressure

drier contact surfaces

the amount of debris on contact pointthe amount of debris on contact point

resistance value of the debris at the contactmargin

The accepted practice by researchers andregulators has been to assume worst-case(lowest practical values) for contactresistances.

Sensory and Motor NerveStimulation and Response

1.5

2

2.5

3

3.5

Ne

rve

Re

spo

nse

0

0.5

1

1.5

0 1 2 3 4

Ne

rve

Re

spo

nse

Current Exposure

Threshold of Response(so that they do not fire all the time)

The Bio-mechanics of NerveStimulation

As current levels increase

No response below threshold

Sensory responses just aboveSensory responses just abovethreshold

Tingling, warmth, startle

Motor response

Involuntary muscle contraction, twitch

Pain

Behavioral ResponsesEach animal will have a behavioral responsethreshold to current exposure for a particularcontact pathway

Studies have used a variety of behavioral responsethresholds

most sensitive behavioral indicators of perceptionmost sensitive behavioral indicators of perceptionhigh variability, rapid acclimation to unfamiliar

annoyance and/or aversionChange eating / drinking behaviors

Current applied in a periodic mannerrepeated series of startle behaviors

Involuntary muscle contractionMost repeatable, Higher current threshold than sensation

Literature Review 1962-2008

61 Studies of voltage/current applicationto cows

26 Studies of voltage/currentapplication to other farm species

8 Studies of Cow Trainers and Fencers

application to other farm species

8 Studies of Cow Trainers and Fencers

Studies Reviewed forData Collection

Data analysis

Repeatability

Research Groups Farm Animals andElectrical Exposures

USU Minnesota - Gustafson/ Cloud/ Brennan/

Appleman/Henke-DrenkardCornell - Aneshansley/Gorewit/Price/Wilson/

Ludington/SouthwickMichigan - Surbrook/Kirk/Althouse/FickU Missouri - Currence/ Winter/ Stevens/ DickJohns Hopkins - ReillyPurdue - Albright

CanadaOntario- RushenAlberta - ThorneMcGill Burchard/ Rodriquez/New Liskeard - GumprichAustraliaDamaskNew ZealandPhillips, Whittlestone,Purdue - Albright

UWEX Hendrickson / KammelUSDA Beltsville - LefcourtWashington - Lee et al.USDA ARS StetsonU of Wisconsin - Reinemann/ Scheffield/ Wiltbank/

LeMire/ Armentano/ McGuirk/ Laughlin/PSCW - Dasho/ Cook/ ReinesDATCP - Kasper/ Roberts/Hansen/RyderMinnesota PUC - Hendrickson/ PatochQuigleyHalvorsonGodcharles

Phillips, Whittlestone,Woolford, SalisburyGermanyBergstenOswaldSwedenAlgersHultgrenPehrsonFranceAroParisTech - Roussel, Ragalma

29 groups more than 70 people

New Zealand: Phillips,1962

First published Cow study

Voltages on milking plants in New Zealand0 to 20 V - most between 3 and 10 V.

Sources of voltage: unbalanced loads andSources of voltage: unbalanced loads andHigh resistance neutrals

Voltage applied teat-to-rear hooves

After these experiments 3 volts waschosen as a likely minimum level forresponse.

New Zealand: Woolford, 1972

Use Current Exposure in an attempt toreduce variability of responses

front to rear hooves

wetted flank to 4-hooveswetted flank to 4-hooves

changes in cow behavioral when currentsreached 3 to 8 milliAmpere

judged to be uncomfortable for currentsof 4.5 to 12 milliAmpere

New Zealand: Whttlestone,1975

Operant conditioning system as a moreobjective method of measuringbehavioral responses

cows turned on an electric current bycows turned on an electric current bypressing a second manipulanda in order toreceive crushed barley

behaviors changed with currents of

6 mA for the udder, 7 mA for one teat

6 mA for rump, 4 mA chest area.

Early North American Studies

Craine, 1975

Groups of 70 and 30 cows exposed tovoltages on a waterer ranging from 0(control treatment) to 8 volts.(control treatment) to 8 volts.

Mild aversion noted at 3 volts

Suppression of water above 4 volts

8-volt treatment discontinued after 1 daybecause many cows refused to drink

United States Department ofAgriculture Research

Lefcourt (1982a) EKG patches shaved areas onthe front and rear legs

Reduce the problem of contact resistance

Four cows mild response at about 3 mA

One cow mild responded to 0.7 mA (cut in skin?)

Lefcourt (1982b) 6 cows to subjected to 5 mAbefore and during milking

Milk yield and milking time decreased forintermittent current

Continuous treatment had a variable effect on milkyield, milking time and hormonal responses

some cows seemed to adapt and enjoy stimulation.

USDA: Lefcourt (1985)7 cows at 3.6 mA and 6 cows to 6.0 mA at a.m. andp.m. milkings for 7 days, subdermal probe

One cow removed from the 6.0 mA group because ofsevere behavioral responses

Milk yield, milking time, and Wisconsin Mastitis Testscores were not affected

Peak milk flow rate increased slightlyPeak milk flow rate increased slightly

Behavioral events increased

Short Term Heart rate elevation

Concluded negative effects of electrical shock onmilk production or mammary health most likely notrelated directly to shock

severe behavior would result in managementproblems.

USDA: Lefcourt (1986)

Seven lactating cows exposed to 60 Hz currents of 0,2.5, 5.0, 7.5, 10, then 12.5 mA, biweekly.

As mA increased, cows became more agitated and

two cows not shocked at 12.5 mA due to severe behavioralresponsesresponses

Short term Heart rate increased at 10 mA and 12.5 mA

Prolactin, norepinephrine and glucocorticoids wereunaffected

Epinephrine doubled in two exceptional cows at 10 mA

Dramatic behavioral responses not correlated withsignificant or prolonged physiological responses

Electrical exposure not considered a reliable way toinduce stress in cows.

The University of MinnesotaElectrical resistance of milking machinecomponents

milk hose 30,000 Ohms to 80,000 Ohms

minimum resistance from the claw throughthe cow to the floor was 3,000 Ohms.the cow to the floor was 3,000 Ohms.

8 pathways through dairy cows

mean path 359 ohms for a mouth-allhooves pathway to 738 ohms for a front-rear hooves pathway

U Minn. suppression of alearned response to obtain food

6.0 mA front-rear hooves shock

Muzzle-all-hooves shock as low as 1.0 mAsuppressed plate pressing behavior

learned escape response to a front-rearlearned escape response to a front-rearhooves shock above a normal activitylevel occurred between 2.0 and 3.0 mA.

exposure conditions were not typical offarm exposures.

Appleman and Gustafson1985 review

0.7 V (60 Hz rms)

endocrine response > 3 V or 8mA (60 Hz rms)

Resistance 350 to 1700 ohmsfor different pathways

Updated review 1987Revised based on additional research

milking machine not likely pathway, highresistance

no direct and causal relationship betweenno direct and causal relationship betweenvoltage exposures and milkingperformance and animal health

Problems may occur

mouth-all hooves > 1.0 volt.

step potential > 2.0-volt

Thresholds to DC current(Gustafson 1988)

behavioral response to DC pulsewidths ranging from 0.1 to 300millisecondsmilliseconds

Body resistance decreased

more current required to elicitbehavioral responses

with narrower pulse widths.

Research at Cornell I

0, 0.5, 1, 2 and 4 V applied to waterbowls for 21 days

Two cows out of 6 did not drink for 36hours at 4VTwo cows out of 6 did not drink for 36hours at 4V

All 28 others drank normal amounts ofwater within 2 days.

Higher voltage = more delay to drink thefirst gallon of water.

Cornell II

3, 4, 5 and 6 V to water bowls for 48 hours84 cows Heifers

2 heifers at V and 2 heifers at 6 V did not drinkfor 36 hours.for 36 hours.

Within 2 days those that drank were drinkingamounts that were not significantly differentfrom the time before voltage was placed on thewater bowl.

Higher voltage = more delay to drink the firstgallon of water.

Cornell III

Discontinuous voltages 5 V and 8Vapplied water bowls to rear hooves.

Five temporal patterns were used to applyFive temporal patterns were used to applyvoltage of 50% of the time

Drinking patterns not consistent but nosignificant change in amount of waterconsumed.

Cornell IV

0, 1, 2 or 4V applied from waterer to a metalgrid (front hooves) over a full lactation (305days).

4 groups of 10 cows each4 groups of 10 cows each

Milk weights, SCC, milk fat, protein, feedconsumption and water intake showed notsignificant differences between groups.

Voltages did not significantly influence cowhealth or reproductive performance.

Cornell V

Current applied to teats during milking.

Heifers kicked at milking machines whencurrent exceeded 5 to 12 mA.current exceeded 5 to 12 mA.

Older cows kicked at milking machines at8 to 18 mA.

New Liskeard College of AgriculturalTechnology

Groups of 30 cows with 112 day exposrues

continuous low-level voltage w/ 2 periods ofhigher levels:

0.30 V and 1.0 V0.30 V and 1.0 V

0.75 V and 2.5 V

0.75 V and 5.0 V

level (1) higher milk fat percentage

Milking time longer for level (2)

residual effect on milk production 2 periods after thetreatment at level (3)

Concluded that up to 5.0 V in well managed tie-stall dairyoperations unlikely to cause observable changes in cowmilk production or behaviour.

USDA 1991 Summary

Consensus opinion of 15 credibleresearchers

distressed that our research resultswere being misinterpretedwere being misinterpreted

Recommend action levels from 2 to 4Volts

As conservative as possible to account forindirect losses due to problems resultingfrom inappropriate response of farmers tochanges in animal behavior

USDA 1991 Summary

To relate voltage measurements tocurrent, the worst case (500 Ohms) andmore realistic (1000 Ohms) Resistancswere used.were used.

Attempts to reduce cow contact voltagesto below 0.5 to 1.0 V are unwarranted,and totally unnecessary

No contradiction to these findings in2003 NRAES review.

Synthesis of OEB Review of ResearchFindings

Compilation of all knownexperiments in which responses tovoltage or current exposure weredocumentedvoltage or current exposure weredocumented

Spanning 1962 to 2007 (45 Years)

From Research Groups Around theWorld

Over 100 Scientists Represented

40%

50%

60%

70%

80%

90%

100%

Pe

rce

nto

fCo

ws

Re

spo

nd

ing

First Behavioral Response,n=365

Discomfort, n = 133

Aversion, N =36

0%

10%

20%

30%

40%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Pe

rce

nto

fCo

ws

Re

spo

nd

ing

Current Level (mA, rms)

Over 450 cows withconstant CURRENT exposure

Many studies report on single animal responses

Behavior response thresholds varyModerate: Blink of an eye, nose twitch

Pronounced: Involuntary muscle contraction

Aversive: Stop DrinkingAversive: Stop Drinking

Most behavioral response thresholds betweenfrom 2 and 8 milliAmps (60 Hz rms)

One study reported moderate responses at 1 mA witha nose press to metal plate (current concentration)

Aversion occurs at higher levels than behavioralresponse

Over 300 cows withconstant VOLTAGE exposure

Most studies report on group average rather thansingle animal responses

Many studies report moderate behavioral betweenthe range from 2 and 8 volts (60 hz rms)

Studies using metallic waterer - metallic floor plateStudies using metallic waterer - metallic floor platefound some delays to drink at 1 Volt

Studies using concrete floor did not report behavioralchanges at 1 Volts

Some studies report severe aversion of a fewanimals between 4 and 8 volts

Refusal to drink for up to 36 hours

Kicking at milking unit

Over 300 cows with constant voltageexposure

Most responses 2 to 8 Volts

Over 450 cows with constant currentexposure

Most responses 2 to 8 MilliampsMost responses 2 to 8 Milliamps

Over 750 Cows Tested

1000 Ohms reasonable estimate of cow+ contact resistance in real-worldsituations

May be some unusual cases as low as500 Ohms

Animal Response to StrayVoltage

Avoidance behavior

Milk production

Well documented

Documented onlyfor extremeexposure

Somatic cells

Reproduction

Milkout problems

Stress Hormones

exposure

Not documented

Not documented

Only at very highlevels

Only at very highlevels

Exposure Conditions Requiredto Produce an Effect

Adverse effect requires BOTH annoyingcurrent AND forced exposure

Contact resistance500 ohms is worst case500 ohms is worst case

1000 Ohms is typical

Dry contacts or bedding will increasecontact resistance

LocationAreas vital to normal daily activities

Times / dayAnnoying stimulus must occur frequently

Levels That Affect Farmperformance

Current exposure < 3 mA mayproduce mild behavioral changes in asmall percentage of cowssmall percentage of cows

Corresponding to < 2 to 3 Volts

Aversive behaviors likely short-lived

No physiological changes

Changes likley undetectable on mostfarms

Levels That Affect Farmperformance

Current exposure from 3 to 6 mA mayproduce observable behavioral changes insome cows

Corresponding to 3 to 6 VoltsCorresponding to 3 to 6 Volts

May produce short term changes ineating/drinking for some cows dependingon location and time of exposure

Likely difficult to detect

Aversive behaviors likely short-lived

May produce mild increase in stresshormones in some cows

Levels That Affect Farmperformance

Current exposure above 6 mA likely toproduce some behavioral changes in mostcows and pronounced behaviors in somecowscows

Corresponding to > 6 Volts

Likely to produce changes in eating /drinking for some cows depending onlocation and time of exposure

May be detectable on some farms

May produce increase in stress hormonesin some cows

Diagnosis

Animal behavior or other symptomsCANNOT be used to diagnose strayvoltage problems

All known responses to stray voltageAll known responses to stray voltageexposure can be produced by other causes

The ONLY WAY to determine if strayvoltage is a potential cause is to performelectrical testing

Voltage/Current Sensitivity byContact Location and Animal Type

Exposure at watering devicesExposure at feeding devicesExposure at feeding devicesExposure during milkingExposure at building transitionsExposure in resting areas,pastures and other FarmLocations

Exposure at watering devices

Likely location for voltage exposureMetallic water systems connected to grounding systemArea necessary for animalsWorst case (lowest) contact resistances on clean, wetfloorsfloorsMetallic / heated watering devices highest riskAlternate watering locations w/ lower voltage reduceor eliminate effectsNon Metallic watering devices much lower risk highcontact resistanceEquipotential Planes required around watering devicesSevere aversion > 4 Volts / 8 mA

Exposure at feeding locations

Floor feeding unlikely location forproblems

High resistance of feedLow level step potentials if metal infloorLow level step potentials if metal infloor

Metallic, electrical feeding devicespossible location for aversion

Resistance values at muzzle and floorhigher than for metallic wateringdevices

Learned Behavior Avoid Contact

Exposure during milking

Highly unlikely locationfor problems

Milk hose has very high resistanceMilk hose has very high resistance

Milking parlors usually well bonded(equipotential)

Body resistances high for hide/stallcontact

Exposure at building transitions

Severe wiring problems mayproduce aversive step potentials ifequipotential plane not installed

Contact resistances likely > 1000Contact resistances likely > 1000Ohms

May make animal handling moredifficult but unlikely to affectfeeding / drinking behaviors

Exposure in resting areas, pastures andother Farm Locations

Highly unlikely location forproblemsHigh resistance contacts DryHigh resistance contacts Drybedding to hide / hoovesstep potentials very low comparedto contact with electrical devicesMetal in floors acts asequipotential

On-Farm Mitigation Measures

Farm Wiring

Equipotential PlanesEquipotential Planes

Voltage Suppression andFilters

On farm isolation

Utility Mitigation Measures

Distribution Wiring

Neutral IsolationNeutral Isolation

Mitigating Other Sources

7. Regulatory Approaches andGuidelines to Reducing the Impact ofStray Voltage on Farm Operations

Wisconsin

Michigan

VermontVermont

Idaho

Minnesota

New York

Pennsylvania

Cornell VI

The average current required to cause cows tostop drinking ranges from 4.9 to 132 mA rmsfor steady 60 to 30k Hz currents

38 to 80 mA peak for DC pulses from 0.4 to 0.138 to 80 mA peak for DC pulses from 0.4 to 0.1ms in duration.

8.2, 9.3, 9.7 and 10.7 mA rms for steady, 30cycles, 15 cycles and 6 cycles of 60 Hz

180 Hz +60 Hz components peak currentexplained responses better than rms

60 Hz + DC bias of 0.5 to 2 V did notsubstantially change the response

Sensitivity to 60 Hz andother waveforms

ASAE 99-3152 Aneshansley and Gorwit

Cows less sensitive to high frequency andshort duration currents

No effect of DC bias on sensitivityNo effect of DC bias on sensitivity

Some differences between RMS sensitivitywith VERY LARGE harmonic content.

No difference when measured as peak values

Explained by other research.

100.00

1000.00

10000.00

Thre

shold

Curr

ent,

(Peak

mA

)Cornell and Wisconsin Data Compared

1.00

10.00

10 100 1,000 10,000 100,000

Frequency (Hz)

Thre

shold

Curr

ent,

(Peak

mA

)

Cornell VII

0, 1, 2 and 4 V applied between waterers andrear hooves

16 animals with histories of sub-clinical mastitis

16 animals challenged with mastitis organism

No significant change in milk production, feedconsumption, milk fat and protein, SCC, bloodchemistry, milk microbiology and serumcortisol

Effects of Voltage/Currentexposure on Mastitis

ASAE 99-3151 Gorewit andAneshansley

0, 1, 2 and 4 V applied to water bowl0, 1, 2 and 4 V applied to water bowl

Teats dipped after milking withStrep uberis culture

Exposure of up to 4 Volts did notpromote clinical mastitis

Dairy Cow Response to ElectricalEnvironment

UW Research UpdateUW Research Update

Douglas J. Reinemann, Ph.D. Professor ofBiological Systems Engineering

University of Wisconsin-Madisonwww.uwex.edu/uwmril

UW Research Initiated andFunded by Wisconsin Dept. Of

AgricultureConcerns raised by citizens strayvoltage advisory board

Transient voltageTransient voltage

"Objectionable currents

Magnetic fields

Other phenomena beyond "classicalstray voltage"

UW Research Team1. D. Reinemann - UW Biological Systems Eng

2. L. Stetson - USDA-ARS

3. Steven D. LeMire, UW Biostatistics

4. N. Laughlin UW Psychology, Animal Behavior

5. J. P. Reilly - Johns Hopkins APL, Electro-pathology5. J. P. Reilly - Johns Hopkins APL, Electro-pathology

6. S. McGuirk - UW Vet School, Physiology

7. E. Nordheim - UW Statistics

8. L. Armentano - UW Dairy Science

9. M. Rasmusssen, Danish Inst. Agricultural Science

10. Milo C. Wiltbank, UW-Dairy Science

11. Lewis G. Sheffield, UW-Dairy Science

Sensitivity (BehavioralResponse) Tests, 500 Cows

Muzzle to hooves

60 Hz, 1, 5, 9, 10 cycles

500 Hz, 1 cycle500 Hz, 1 cycle

6000 Hz, 1, 9, 100 cycles

50,000 Hz, 1, 5, 833 cycles, sine, 1/2sine, square

Milking machine exposure

Sensitivity to magnetic fields

Volts (Zero to Peak)Muzzle - Hoof

Volts (Zero to Peak)Hoof - Hoof

Approximate 60 Hz Steady State Behavioral Response Distribution

2 3 4 5 7

Volts (Zero to Peak, measured across 500 Ohm resistor)

J.P. REILLYBIO-

ELECTRICITY1998

Behavioral response for 5% most sensitive cows, sine wavesmuzzle to hooves exposure

100

1,000

10,000

Vo

lta

ge

(Ze

roto

Pe

ak)

50

0O

hm

Co

wC

on

tact

1 cycle Biphasic

1 cycle Monophasic

Multi CycleFencers

1

10

0.1 1 10 100 1000 10000

Phase Duration (microseconds) = time between zero crossings

Vo

lta

ge

(Ze

roto

Pe

ak)

50

0O

hm

Co

wC

on

tact

Dairy Cow Response to MultipleFrequency WaveformsFrequency Waveforms

Douglas J. Reinemann, Ph.D.

Paul D. Thompson, PhD

Charles Forster, Mr. Pulsar

University of Wisconsin- Madison

Single Frequency Waveforms

1.5

2.0

2.5

3.0

Se

ns

itiv

ity

Ra

tio

0.0

0.5

1.0

1.5

0 2 4 6 8

Time (ms)

Se

ns

itiv

ity

Ra

tio

Average Response to60 Hz = 11 mA

Multiple Frequency Waveforms

1.0

2.0

3.0

4.0

5.0 Response tocombined 60Hz +

Narrow pulse sameas for Narrow pulse

alone

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

0 2 4 6 8 10 12 14 16 18

Time (ms)

When 60 Hz peak isbelow 60 Hzresponse level

Multiple Frequency Waveforms

1

1

2

2

When peak of Pulseis below Responselevel for the pulsealone

-2

-2

-1

-1

0

0 2 4 6 8 10 12 14 16 18

Time (ms)

Response levelfor 60 Hz peak isthe same as for60 Hz alone.

1

1.5

2

2.5

Response toPulse + Ring notdifferent fromPulse alone

-1

-0.5

0

0.5

2000 2100 2200 2300 2400 2500 2600

Sensitivity to combined frequencycomponents

Combining waveforms did not changesensitivity to individual waveformsCombining waveforms did not changesensitivity to individual waveforms

UW Aversion Tests (120 Cows)

1 cycle 60 Hz

Water bowl tofloor

1 per second

3 week

Exposure method

Control

Reaction level

1.5 timereaction level3 week

exposure

1 cycle 6000 Hz

Water bowl tofloor

1 per second

3 day exposure

reaction level

100

120

140D

aily

Wa

ter

(L)

Control P 7-13mA P+ 8-14mA P++ 9-17mA P*11-20mA

60

80

-7 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 7

Days

Da

ily

Wa

ter

(L)

1

1.05

1.1

Fra

cti

on

of

Da

ily

Wa

ter

Co

ns

um

ed

Control R(7-13mA) R+(8-14mA)

R++(9-17mA) R*(11-20mA)

0.8

0.85

0.9

0.95

Pre Test Post

Fra

cti

on

of

Da

ily

Wa

ter

Co

ns

um

ed

21 Day Average Water

Single Cycle 60 Hz AversionChange in 3 Day Average Water Consumption

-2

0

2

4

6

Ga

llo

ns

/C

ow

/D

ay

-10

-8

-6

-4

-2

R 1.2 R 1.5 R

Exposure Level

Ga

llo

ns

/C

ow

/D

ay

Single Cycle 60 Hz AversionHours delay to drink first gallon of water

15

20

25

30

Ho

urs

0

5

10

15

Control 1.2 R 1.5 R

Exposure Level

Ho

urs

Behavioral response for 5% most sensitive cows, sine wavesmuzzle to hooves exposure

100

1,000

10,000

Vo

lta

ge

(Ze

roto

Pe

ak)

50

0O

hm

Co

wC

on

tact

1 cycle Biphasic

1 cycle Monophasic

Multi CycleFencers

1

10

0.1 1 10 100 1000 10000

Phase Duration (microseconds) = time between zero crossings

Vo

lta

ge

(Ze

roto

Pe

ak)

50

0O

hm

Co

wC

on

tact

Continuous Vs. IntermittentExposure

Hrs Delay Ave Diff. P-value Significant

Control vs.One shock

-0.4 .14 NoOne shock

Control vs.Intermittent

-0.4 .21 No

Control vs.Continuous

+5.6

AgroParisTech Roussel(2007)

avoidance test threshold level

steps of 0.3 Volts up to 5 Volts applied to feedingcup

2.3V, % total feed and the time spent eating in 2.3V, % total feed and the time spent eating inthe electrified feeder decreased

> 3 Volts heifers changed more quickly to the non-electrified feeder

> 2 Volts more muzzle-grooming and head shaking

2.3V appeared to be the threshold at whichavoidance behaviour starts

Effects of Stray Voltage on Behaviour, Stress

Physiology and Production Parameters of Sheep and

Dairy Cows.Short and mid-term effects

117

AgroParisTechC. DUVAUX-PONTER, F. GALLOUIN, S. ROUSSEL,

K. RIGALMA (PhD since 2006)Experimental farm of AgroParisTech

M. SAADE, D. TRISTANT and the farm staffTrainees and assistants

A. BARRIER, A.-C. BURGE, M. CARRIERE, C. CHARLES, M. ENNIFAR, C. EON, A.MALHERBE, P. MALSERT, A. OLIVEIRA, P. PIQUEREL, C. SCHREINER

RTE - EDFF. DESCHAMPS, L. DEVEAUX, F. FORTIN, J.-P. GERNEZ, T. LOUYOT

Percentage of feed eaten in the electrified feeder

n = 20 (CONT heifers are used to control day effect)

Reaction threshold in heifers (experiment 3)

60

80

100NS

*** ***NS NS NS NS NS NS

*** ***** ***

********

Reaction threshold = 2.3 V

118Voltage (V) applied

0

20

40

60

0 0.3 0.6 1 1.3 1.6 2 2.3 2.6 3 3.3 3.6 4 4.3 4.6 5

%

Latency to switch to the non-electrified feeder(seconds)

Reaction threshold in heifers (experiment 3)

Reaction threshold = 2.3 V

80

100 ******

NS NS NS NS NS NS

****** ******** **

NS

119

Voltage applied (V)

0

20

40

60

80

0 0.3 0.6 1 1.3 1.6 2 2.3 2.6 3 3.3 3.6 4 4.3 4.6 5

seco

nds

*** ******

n = 20 (CONT heifers are used to control day effect)

Percentage of heifers performing at least one abrupthead movement during the 2-min test

CONT n = 20

20

25

30 NS * *

Reaction threshold in heifers (experiment 3)

120

VOLT n = 20

0

5

10

15

20

0.3 to 1.6 V 2.0 to 3.3 V 3.6 to 5.0 V

%

Rigalma (2007) 3-week 3.3 Voltexposure metallic feeders

continuous (C) or unpredictable (U)

20 nave (NH)and 20 experienced (EH) heifers

unpredictable exposure

more time eating in the electrified feeder

more abrupt head movements and more muzzle-groomingmore abrupt head movements and more muzzle-groomingbehaviors

than those in the continuous exposure group

No behavioral differences between NH and EH

NH higher cortisol concentrations on first day

NHC ate more and changed feeder quicker than theNHUexposure group

Unpredictable exposure had more difficulty in adaptingand that past-experience seemed to reduce the response.

Rigalma (2008)

unpredictable exposuremay not offer sufficienttime to the heifers totime to the heifers tolearn how to adapt.

Minnesota Science AdvisorsEarth Current Study

Endocrine And Immune FunctionResponse Of Dairy Cows To Electrical

Current Exposure

Minnesota / WisconsinOpinion Survey

Conducted by USDA AgriculturalStatistics service

Random sample of 1300 farms

Electrical exposures listed in

Random sample of 1300 farms

Electrical exposures listed inbottom 1/3 of 26 animal health andproduction concerns

Minnesota Field Study

60 Hz voltage below perception onall farms

Motor starts below perception

High frequency events belowHigh frequency events belowperception

Magnetic fields below level ofconcern

Widespread problems with fencersand trainers

Minnesota Field Study

Step Potential (Mainly from localsources)

Barnyard 1 - 50 mV

Field 0 - 11 mVField 0 - 11 mV

Stall 1 - 30 mV average (3-150 mVMaximum)

Further study of earth currents fromdistant sources cannot be justified

Physiological effects of small steppotentials being investigated

Magnetic FieldMeasurements on Wisconsin

Dairy FarmsDasho ASAE 963071

Measurements on 106 Farms

Levels in Barns Lower Than inLevels in Barns Lower Than inResidence

No Relationship with Cow ContactVoltage

Not a likely source of problems

Minnesota Science AdvisorsGround Current Study:

The Hypothesis

Continuous contact of confined cowsto low level (sub perception)voltage/current may produce,voltage/current may produce,

Electric fields inside the cow atlevels high enough to produceBiological effects

Change in cow activity in response tocurrent exposure

10

20

5m

inc

ha

ng

ein

ac

tivit

y

-20

-10

0

0.5 R 0.75 R 1.0 R 1.5 R

Treatment Level

5m

inc

ha

ng

ein

ac

tivit

y

24

Co

rtis

olco

nce

ntr

atio

n(n

g/m

L)

No increase in Cortisol for CurrentExposure below behavioral response

-4-2

0

0.5 R 0.75 R 1 R 1.5 R

Co

rtis

olco

nce

ntr

atio

n(n

g/m

L)

40

50

Paired T-testp = 0.0001

No Cortisol response for current exposureBig Cortisol response for hoof trimming

010

20

30

Cort

isol(n

g/m

l)

Before

Current

After

Current

1.5 R

Before

Hoof

Trimming

After

Hoof

Trimming

Treatments applied duringmilking

Control

Hoof-hoof voltage exposure belowsensitivity threshold

Milking machine induced stressMilking machine induced stress

Measures

Stepping

Average and peak milk flow during milking

Pounds of milk yield

Milking time

Milk Yield (kg) 1.19+ 0.13

0.24 + 0.15

PulsationFailure

1 mA currentexposure

No response to currentSome response for broken milking

machine

Average Flow Rate(kg/min)

0.24 + 0.15

Maximum Flow Rate(kg/min)

0.29 + 0.04

Activity (weight shifts/ milking)

-5.84 *** -1.28

Strip Yield (% ofquarters > 10 ml)

-0.10 0.09

Immune response tocontinuous low level current

exposure

1 mA Exposure Front - Rear Hoof,

10 Minutes off/on for 2 weeks10 Minutes off/on for 2 weeks

No change in

Immune function response

Time and pattern of laying

Time to re-enter stall after milking

Immune Tests

Blood samples twice weekly

lymphocyte blastogenesis

Dose responses to standard mitogens,

S. aureus, Phytohemagglutinin, PokeweedS. aureus, Phytohemagglutinin, PokeweedMitogen and Concanavalin A

Chemiluminescence measure of Oxidativeburst

Interluken I

Cortisol

Conclusions

No difference between control andtreatment cows for any of the 3 mainresponse variables

Statistically significant difference for 1 ofStatistically significant difference for 1 of10 of the secondary response variables

But did not appear to be consistent withother observations

Collectively, these results suggest thatexposure to 1 ma of current for two weekshad no significant effect on the immunefunction of dairy cattle.

WI Immune II ResultsMost measures were not affectedA small subset of immune system regulators

showed possible changes:Could be Type I errors, due to the large

number of hypotheses tested.number of hypotheses tested.The magnitude of effect was relatively small,

compared to that often observed in theliterature in response to major immunesystem challenges

Immune function conclusionsSmall subset of immune systemregulators showed possible changes

most disease processes affect a widerspectrum of regulators

Type I errors, large number tested (?)

Any possible impacts of electricalAny possible impacts of electricalexposure on immune function healthand disease are of relatively small anddifficult to detect

Collectively, these results suggestthat exposure to 1 ma of current fortwo weeks had no significant effect onthe immune function of dairy cattle

Findings of the MinnesotaScience Advisors

We have not found credible scientific

evidence to verify the specific claim that

currents in the earth or associatedcurrents in the earth or associated

electrical parameters such as voltages,

magnetic fields and electric fields, are

causes of poor health and milk

production in dairy herds

Wisconsin Field Study

Stray Voltage Analysis Team (SVAT)Public Service Commission of Wisconsin(PSCW)

Wisconsin Department of AgricultureWisconsin Department of AgricultureTrade and Consumer Protection(WDATCP)

> 360 Investigations 88-98

Electric Utilities8000 First-Time Farm Investigations93-2007

PSCW Field Study8000+ Farms

No Correlation Between

Milk production or Somatic CellCount andCount and

Primary NEV

Secondary NEV

Cow Contact Voltage

Ground Rod Current

15000

20000

25000

30000

35000

Milk

Pro

du

cti

on

(RH

A)

0

5000

10000

15000

0 50 100 150 200 250 300

Ground Current (mA)

Milk

Pro

du

cti

on

(RH

A)

R2 = 0.00p = 0.97

1000

10000

SC

C

10

100

0 50 100 150 200 250 300

Ground Current (mA)R2 = 0.02P = 0.11

15,000

20,000

25,000

30,000

Mil

kP

rod

ucti

on

(RH

AL

b/c

os)

5,000

10,000

15,000

0.00 0.20 0.40 0.60 0.80 1.00

Cow Contact Voltage

Mil

kP

rod

ucti

on

(RH

AL

b/c

os)

R2 = 0.01p = 0.29

800

1,000

1,200

1,400

1,600

SC

C(x

1000)

0

200

400

600

0.00 0.20 0.40 0.60 0.80 1.00

Cow Contact Voltage

SC

C(x

1000)

R2 = 0.03p = 0.11

15000

20000

25000

30000

Mil

kP

rod

ucti

on

(RH

AL

b/C

ow

)

0

5000

10000

0 0.5 1 1.5 2 2.5 3

Primary Neutral to Earth Voltage

Mil

kP

rod

ucti

on

(RH

AL

b/C

ow

)

R2 = 0.01p = 0.33

800

1000

1200

1400

1600

SC

C

0

200

400

600

0 0.5 1 1.5 2 2.5 3

Primary Neutral to Earth VoltageR2 = 0.00p = 0.75

Average Monthly Milk Production in Wisconsin

43

44

45

46

47

48

Lb

/Co

w/D

ay

38

39

40

41

42

43

Jan-

95

Mar

-95

May

-95

Jul-9

5

Sep-

95

Nov-95

Jan-

96

Mar

-96

May

-96

Jul-9

6

Sep-

96

Nov-96

Jan-

97

Mar

-97

May

-97

From Wisconsin Ag Statistics 97

Lb

/Co

w/D

ay

Monthly Average SCC from Upper Midwest

Federal Orders #68 and #30, and IOU data

350

400

450

SC

C

FO 68 UMW

FO 30 CHI

iou

200

250

300

Jan-9

3

Ap

r-9

3

Jul-9

3

Oct-

93

Jan-9

4

Ap

r-9

4

Jul-9

4

Oct-

94

Jan-9

5

Ap

r-9

5

Jul-9

5

Oct-

95

Jan-9

6

Ap

r-9

6

Jul-9

6

Oct-

96

SC

C

r = 0.59

Review of Sensitivities ofOther Species

Swine

greater than 3.0 mA was needed to affect drinkingtime and 4.0 mA to affect consumption.

feed intake, daily gain were lower in the 5 V groupthan 2V and controlthan 2V and control

up to 8 V does not impair the welfare, reproductiveperformance, or health of sows and suckling pigs

Up to 8 V no significant effects on feeding,drinking, sitting or lying activities. slight increase inrooting bouts 5-8V head butting 2-5V

Review of Sensitivities ofOther Species

Sheep

Above 5.5 V ewes tended to spendmore time eating and to eat moremore time eating and to eat morefrom the non-electrified feeder

At 5V and upwards, lambs spentless time eating in the electrifiedfeeder

Review of Sensitivities ofOther Species

Poultry

0 to 9 volts did not impair egg production

electrical resistance of hens much higherthan cattle and pigsthan cattle and pigs

as high as 18 V had no effect on hens'production and behavior (2)

stray voltage present in many breederhouses may contribute to floor eggs

factors other than up to 9 V may havebeen causing a floor egg problem.