An Alternative Way of CastrationAn Alternative Way of Castration

Jim AllisonJim Allison

Pfizer Animal HealthPfizer Animal Health

AgendaAgenda

•• Why we castrate pigsWhy we castrate pigs•• Surgical castrationSurgical castration•• Alternatives to surgical castrationAlternatives to surgical castration•• Immunological castrationImmunological castration

–– How it worksHow it works–– EfficacyEfficacy–– Impact on productionImpact on production–– Practical considerationsPractical considerations

Current castration practiceCurrent castration practice

•• No castration No castration –– UK and IrelandUK and Ireland•• Some castration Some castration –– Spain and PortugalSpain and Portugal•• Nearly 100% castration Nearly 100% castration –– rest of Europe and rest of Europe and

most of the world most of the world –– Mostly surgically without anaesthesiaMostly surgically without anaesthesia

Approximately 100 million piglets / year in the EU

Why castrate pigs?Why castrate pigs?

•• To eliminate the risk of boar taint in meat To eliminate the risk of boar taint in meat from sexually mature male pigsfrom sexually mature male pigs

Boar taintBoar taint

•• Unpleasant taste / Unpleasant taste / odourodour in pork from many sexually in pork from many sexually maturing male pigsmaturing male pigs–– Androstenone (testicular steroid, pheromone)Androstenone (testicular steroid, pheromone)–– Skatole (product of Skatole (product of tryptophantryptophan metabolism in the gut, metabolism in the gut,

reduced tissue clearance in males)reduced tissue clearance in males)•• Around 50% of intact males are affected at typical Around 50% of intact males are affected at typical

slaughter weightsslaughter weights–– Fat concentrations exceeding recognized threshold valuesFat concentrations exceeding recognized threshold values

•• Variation in individual consumer susceptibilityVariation in individual consumer susceptibility–– 25% highly sensitive, 75% at least moderately sensitive25% highly sensitive, 75% at least moderately sensitive–– Women more sensitive than menWomen more sensitive than men–– Higher sensitivity in some racial groupsHigher sensitivity in some racial groups

•• Not dangerous, but unacceptableNot dangerous, but unacceptable–– Must be controlled to maintain the viability of pork productionMust be controlled to maintain the viability of pork production

Boar Taint Boar Taint –– Chemical assay Chemical assay Incidence in Incidence in boarsboars

•• Androstenone & skatole in fat tissue from boarsAndrostenone & skatole in fat tissue from boars–– Nearly 50% above the sensory threshold: taintedNearly 50% above the sensory threshold: tainted

Data on file. Pfizer Inc.Data on file. Pfizer Inc.

0.0

0.1

0.2

0.3

0.4

0.5

0.0 0.5 1.0 1.5 2.0 2.5

Androstenone (μg/g fat)

Skat

ole

(μg/

g fa

t)Boar Castrate

Dunshea et al. (2001)

Castration eliminates boar taintCastration eliminates boar taint

-- But is not quite 100%But is not quite 100%

•• Castrated and female pigs in highly Castrated and female pigs in highly contaminated environments can still contaminated environments can still have high skatole concentrationshave high skatole concentrations

•• Occasional Occasional ““apparently castratedapparently castrated”” pigs pigs can have high androstenonecan have high androstenone–– CryptorchidCryptorchid pigs (one or both testicles pigs (one or both testicles

retained in the body)retained in the body)–– IntersexIntersex pigspigs–– Adrenal malfunctionAdrenal malfunction

•• 2.2% (4/180) male castrates had high 2.2% (4/180) male castrates had high androstenone androstenone (Nederveld et al. IPVS 2006)(Nederveld et al. IPVS 2006)

Why castrate pigs?Why castrate pigs?

•• To eliminate the risk of boar taint in meat To eliminate the risk of boar taint in meat from sexually mature male pigsfrom sexually mature male pigs

•• To reduce the incidence of sexual and To reduce the incidence of sexual and aggressive behaviour in boars (and coaggressive behaviour in boars (and co--housed gilts) in the late fattening periodhoused gilts) in the late fattening period

Effects on BehaviorEffects on Behavior

•• Behaviour events per 24 hours at 21 weeks of age *Behaviour events per 24 hours at 21 weeks of age *

*Cronin et al. Applied Animal Behaviour Science (2003) 1999:1-16

0

5

10

15

20

25

30

Aggression Mounting

Boars

Surgicalcastrates

Skin lesions caused by fightingSkin lesions caused by fighting

Castration reduces fighting lesionsCastration reduces fighting lesions

0

0.5

1

Figh

ting

lesi

on s

core

BoarImprovac

Barrow

McCauley et al.(2003)

Pig World (UK) April 2007

Why castrate pigs?Why castrate pigs?

•• To eliminate the risk of boar taint in meat To eliminate the risk of boar taint in meat from sexually mature male pigsfrom sexually mature male pigs

•• To reduce the incidence of sexual and To reduce the incidence of sexual and aggressive behaviour in boars (and coaggressive behaviour in boars (and co--housed gilts)housed gilts)

•• To take advantage of the higher fat content of To take advantage of the higher fat content of castrates (historic reason) castrates (historic reason)

Current practice Current practice –– surgical castration surgical castration

•• Traditional method Traditional method –– without anaesthesia / without anaesthesia / analgesia early in lifeanalgesia early in life

•• Covered by EU Directive 2001/93Covered by EU Directive 2001/93–– Castration Castration ““without tearing of tissueswithout tearing of tissues”” permitted permitted

as an exceptionas an exception–– Must be performed by a trained personMust be performed by a trained person–– After 7 days of life must be performed by a After 7 days of life must be performed by a

veterinarian under anaesthesia and with veterinarian under anaesthesia and with additional prolonged analgesiaadditional prolonged analgesia

Problems with current practice Problems with current practice

•• Animal welfare issueAnimal welfare issue–– Target of welfare activistsTarget of welfare activists–– Concern for retailers and othersConcern for retailers and others–– New legislation is likelyNew legislation is likely

�� Restrictions already in place / planned in Norway and Restrictions already in place / planned in Norway and SwitzerlandSwitzerland

•• Reduces productivityReduces productivity–– Direct losses from surgical complications and Direct losses from surgical complications and

infectioninfection–– Loss of potential Loss of potential –– because castrates are less because castrates are less

metabolically efficientmetabolically efficient

Castration reduces lean tissue deposition Castration reduces lean tissue deposition at high weightsat high weights

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100

200

300

400

500

600

700

800

0 20 40 60 80 100 120 140Live weight (kg)

Empt

y bo

dy le

an d

epos

ition

(g/d

ay)

Group pen BarrowGroup pen BoarIndividually pen BarrowIndividual pen Boar

Suster et al. (2006)

Castration increases fat tissue deposition Castration increases fat tissue deposition at all weightsat all weights

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100

200

300

400

500

600

0 20 40 60 80 100 120 140Live weight (kg)

Empt

y bo

dy li

pid

depo

sitio

n (g

/day

)

IP Barrow

GP Boar

IP Boar

GP Barrow

Suster et al. (2006)

Castration increases FCRCastration increases FCR

0

1

2

3

4

Suster (2005) Dunshea et al(1993)

Dunshea et al(2001) - 23 weeks

Dunshea et al(2001) - 26 weeks

Feed

con

vers

ion

ratio

BoarBarrow

Alternatives Alternatives to current practice to current practice ––boar productionboar production

•• Light weight boar productionLight weight boar production–– Current practice in some marketsCurrent practice in some markets–– Impractical on a European basisImpractical on a European basis

�� Some products need heavier carcassesSome products need heavier carcasses�� Increase in resources and production costIncrease in resources and production cost

•• Boar production at current slaughter weightsBoar production at current slaughter weights–– Genetic selection to reduce boar taintGenetic selection to reduce boar taint

�� Early work also selected undesirable traits (poor growth / Early work also selected undesirable traits (poor growth / fertility)fertility)

�� Work with more specific genetic markers has longWork with more specific genetic markers has long--term term promisepromise

–– OnOn--line carcass screeningline carcass screening�� DoesnDoesn‘‘t exist but technically feasible (et exist but technically feasible (e--nose)nose)�� Added costAdded cost�� Only economically viable if relatively few carcasses are Only economically viable if relatively few carcasses are

rejectedrejected

Still a potential problem of behaviour control Still a potential problem of behaviour control

Alternatives Alternatives to current practice to current practice ––other approachesother approaches

•• Surgical castration with anaesthesia / Surgical castration with anaesthesia / analgesiaanalgesia–– Availability of effective drugs and methodsAvailability of effective drugs and methods–– OnOn--farm practicalityfarm practicality–– Added costAdded cost

•• Semen sorting to produce all female littersSemen sorting to produce all female litters–– Not (yet) viable for routine useNot (yet) viable for routine use

•• Immunological castrationImmunological castration

Physiology of boar taintPhysiology of boar taint

GnRFGnRF

LH & FSHLH & FSHMany steroidsMany steroids(testosterone,(testosterone,androstenoneandrostenone))

FertilityFertilityLibidoLibidoBehaviourBehaviour

TestesTestes

HypothalamusHypothalamus

PituitaryPituitaryBrainBrain

SkatoleSkatole

Immunological castrationImmunological castration

•• Vaccination to immunize against GnRFVaccination to immunize against GnRF–– Stimulate production specific antibodies that bind to GnRF Stimulate production specific antibodies that bind to GnRF

and stop activityand stop activity•• WellWell-- recognized scientific approachrecognized scientific approach

–– Commercially used in pigsCommercially used in pigs�� Since 1998 in Australia and new ZealandSince 1998 in Australia and new Zealand�� More recently in Brazil, Mexico, South AfricaMore recently in Brazil, Mexico, South Africa�� Recently approved for use in SwitzerlandRecently approved for use in Switzerland

–– In wild animal populations for population controlIn wild animal populations for population control–– In man for prostate cancer controlIn man for prostate cancer control

•• Need to overcome the fact that GnRF itself is too Need to overcome the fact that GnRF itself is too small to stimulate an immune response. small to stimulate an immune response. –– Swine approach uses a modified GnRF molecule linked to a Swine approach uses a modified GnRF molecule linked to a

large protein large protein

Mode of ActionMode of Action

GnRFGnRF

LH & FSHLH & FSH

Many steroidsMany steroids

FertilityFertilityLibidoLibidoBehaviourBehaviourAndrostenoneAndrostenone

HypothalamusHypothalamus

PituitaryPituitaryBrainBrain

SkatoleSkatole

XX

XXXX

XXTestesTestes

Immunological castration in pigsImmunological castration in pigs

•• Two doses are required at least 4 weeks Two doses are required at least 4 weeks apartapart–– First dose primes the immune systemFirst dose primes the immune system–– Second dose stimulates antibody productionSecond dose stimulates antibody production

•• Effect is temporary as antibodies decay with Effect is temporary as antibodies decay with timetime–– Reliable control of boar taint from two weeks to 8 Reliable control of boar taint from two weeks to 8

weeks after second doseweeks after second dose–– Time second dose for 4 to 6 weeks prior to Time second dose for 4 to 6 weeks prior to

slaughterslaughter

Mode of ActionMode of ActionAntibody productionAntibody production

RecommendedRecommendedtime for slaughter

�� The 1The 1stst dose primes dose primes the immune systemthe immune system

�� Peak antibody levels Peak antibody levels occur about 7occur about 7--10 days 10 days after the 2after the 2ndnd dosedose

�� Protective antibody Protective antibody levels last until at levels last until at least 8 weeks after least 8 weeks after the 2the 2ndnd dosedose

�� Boar taint is reliably Boar taint is reliably suppressed for at suppressed for at least 8 weeksleast 8 weeks

Weeks after 2nd dose

Level of Boar TaintLevel of Boar Taint

Protective levelProtective levelof antibodiesof antibodies

Level of immunityLevel of immunity

Minimum intervalMinimum intervalof 4 weeksof 4 weeks

The profile of production of antibodies against GnRFThe profile of production of antibodies against GnRF

Leve

l of I

mm

unity

and

Boa

r Tai

ntLe

vel o

f Im

mun

ity a

nd B

oar T

aint

11stst DoseDose 22ndnd DoseDose

time for slaughter

Efficacy of immunological castration in pigsEfficacy of immunological castration in pigs

�� Boar taint preventionBoar taint prevention�� ��99% effective (similar to surgical castration), shown by 99% effective (similar to surgical castration), shown by

sensory panels and measurement of taint compoundssensory panels and measurement of taint compounds

�� Pork from treated pigs indistinguishable from that of females Pork from treated pigs indistinguishable from that of females and surgical castrates (all superior to boars)and surgical castrates (all superior to boars)

�� Male behavior controlMale behavior control�� Incidence of mounting and aggressive behaviour rapidly Incidence of mounting and aggressive behaviour rapidly

declines to levels similar to surgical castratesdeclines to levels similar to surgical castrates

�� Effects on testicular sizeEffects on testicular size�� Testicles become smaller than those of untreated boarsTesticles become smaller than those of untreated boars

�� Important tool for assessing complianceImportant tool for assessing compliance

Efficacy Efficacy -- Boar Taint PreventionBoar Taint PreventionIncidence in Incidence in boarsboars

•• Androstenone & skatole in fat tissue from boarsAndrostenone & skatole in fat tissue from boars–– Nearly 50% above the sensory threshold: taintedNearly 50% above the sensory threshold: tainted

Data on file. Pfizer Inc.Data on file. Pfizer Inc.

Efficacy Efficacy -- Boar Taint PreventionBoar Taint PreventionIncidence Incidence afterafter Immunological CastrationImmunological Castration

•• Androstenone & skatole in fat tissues after IC Androstenone & skatole in fat tissues after IC –– Taint compounds below sensory threshold in ~100%Taint compounds below sensory threshold in ~100%

Data on file. Pfizer Inc.Data on file. Pfizer Inc.

Effects on BehaviourEffects on Behaviour

*Cronin et al. Applied Animal Behaviour Science (2003) 1999:1-16

� Second dose given at 18 weeks of age

•• Behaviour events per 24 hours at 21 weeks of age *Behaviour events per 24 hours at 21 weeks of age *

0

5

10

15

20

25

30

Aggression Mounting

Boars

SurgicalcastratesImmunologicalcastrates

Effect on testes size Effect on testes size

�� Immunological castration (IC) causes a decrease in Immunological castration (IC) causes a decrease in testes sizetestes size**

1st dose 22ndnd dosedose

Weeks PostWeeks Post--First DoseFirst Dose

Test

es W

idth

, mm

Te

stes

Wid

th, m

m

(mea

n (m

ean

±±SDS

D ))

BoarBoarICIC

�� Testes size, Testes size, measured as the measured as the maximum width of maximum width of the pair of testes, the pair of testes, was significantly less was significantly less ((P<0.01P<0.01) at wks 6 ) at wks 6 and 8 (or 2 and 4 and 8 (or 2 and 4 wks post 2wks post 2ndnd dose)dose)

*Dunshea Dunshea et alet al., ., J Anim SciJ Anim Sci, (2001) 79: 2524, (2001) 79: 2524--25352535

Effect on testes size Effect on testes size

�� A typical difference in A typical difference in testes sizetestes size

BoarBoar ImmunologicalImmunologicalcastratecastrate

Pigs ~100Pigs ~100--105 kg live weight and ~23 weeks of age105 kg live weight and ~23 weeks of age

Effects on productionEffects on production

Immunological castration does not directly enhance performance Immunological castration does not directly enhance performance but it allows pigs to be managed in a more efficient way:but it allows pigs to be managed in a more efficient way:

•• Entire male pigs are more efficient than castratesEntire male pigs are more efficient than castrates–– Better feed conversion efficiencyBetter feed conversion efficiency–– More lean meat depositionMore lean meat deposition–– Less effluent productionLess effluent production

•• ImmunologicallyImmunologically castrating a few weeks before slaughter is castrating a few weeks before slaughter is more efficient than surgically castrating pigs at 1 week of agemore efficient than surgically castrating pigs at 1 week of age–– Because Because immunologicallyimmunologically castrated pigs spend most of their lives castrated pigs spend most of their lives

as entire malesas entire males

•• In the countries where it is used immunological castration is In the countries where it is used immunological castration is seen as a way to improve production and profitability seen as a way to improve production and profitability –– it is not it is not an added costan added cost

Performance dataPerformance data��Immunological Immunological vsvs. surgical castrates: % improvement. surgical castrates: % improvementTrialTrial No. pigs No. pigs

/ country/ countrySlaughter Slaughter

weight weight (kg)(kg)

FCEFCE ADGADG Lean Meat Lean Meat (% carcass (% carcass

weight)weight)

BackfatBackfat(p2)(p2)

11 24 24 –– MXMX 108108--110110 +7.7*+7.7* NSNS +7.7*+7.7* 22.4*22.4*

22 30 30 –– AUAU ��105105 +15.1*+15.1* +6.8*+6.8* NDND 7.2*7.2*

3**3** 50 50 –– AUAU 9696--100100 +10.0*+10.0* NSNS NDND 17.4*17.4*

4**4** 50 50 –– AUAU 113113--120120 +16.9*+16.9* NSNS NDND 11.7*11.7*

55 260 260 –– CHCH 100100--110110 NDND NSNS +1.4*+1.4* NDND

66 60 60 –– AUAU 105105--110110 +7.9*+7.9* +4.8*+4.8* NDND 12.1*12.1*

77 24 24 –– BRBR 125125--138138 +9.3*+9.3* +10.6*+10.6* +9.3*+9.3* NDND

88 160 160 –– USUS 125125--130130 +8.6*+8.6* NSNS +7.6*+7.6* 8.1*8.1*

FCE = Feed conversion efficiencyFCE = Feed conversion efficiencyADG = Average Daily GainADG = Average Daily Gain

* * statistically significant at p<0.05statistically significant at p<0.05** ** FCE only determined over last 4 weeks prior to slaughterFCE only determined over last 4 weeks prior to slaughterNS = Not statistically significant at p<0.05NS = Not statistically significant at p<0.05

ND = Not determinedND = Not determined

Effect on meat qualityEffect on meat quality

Boars have less fat than castratesBoars have less fat than castratesFat of Fat of immunologicallyimmunologically castrated pigs is castrated pigs is typically between boars and surgical castrates typically between boars and surgical castrates (influenced by feeding, timing and genetics)(influenced by feeding, timing and genetics)High acceptance in taste panelsHigh acceptance in taste panels

Photographs from a study conducted in Asian pigs

Immunological castrate

Surgical castrate

Boar

Practical considerations Practical considerations –– on farmon farm

•• Pigs need to be injected twice, the second injection 4 Pigs need to be injected twice, the second injection 4 to 6 weeks prior to slaughterto 6 weeks prior to slaughter–– Not a problem with appropriate proceduresNot a problem with appropriate procedures

•• Every male pig must be fully dosedEvery male pig must be fully dosed–– SOPs and training to ensure complianceSOPs and training to ensure compliance

•• On farm QA procedures requiredOn farm QA procedures required–– Observation of testicle size and behaviour to identify and Observation of testicle size and behaviour to identify and

treat any possibly missed pigstreat any possibly missed pigs

•• Operator safety is importantOperator safety is important–– Training and use of a safety vaccinatorTraining and use of a safety vaccinator

Experience in existing markets shows that producers Experience in existing markets shows that producers can achieve a very high level of reliabilitycan achieve a very high level of reliability

Ensuring High ComplianceEnsuring High Compliance

•• Smaller testes size following vaccination can be used Smaller testes size following vaccination can be used to assess compliance and efficacyto assess compliance and efficacy

BoarBoar Immunological castrateImmunological castrate

Pigs ~100Pigs ~100--105 kg live weight and ~23 weeks of age105 kg live weight and ~23 weeks of age

On the Slaughter lineOn the Slaughter line

Boar Immunological castratePigs ~100 kg live weight and ~23 weeks of age

Consumer AcceptanceConsumer Acceptance

•• Well accepted in all sectors of Australian market since Well accepted in all sectors of Australian market since 19991999–– Major supermarkets, Asian butchers, high quality Major supermarkets, Asian butchers, high quality

manufacturersmanufacturers•• Well accepted by Australian consumer groupsWell accepted by Australian consumer groups

–– AustAust. & NZ Food Authority, . & NZ Food Authority, AustAust. Consumers Assoc & Public . Consumers Assoc & Public Health AuthorityHealth Authority

•• No restriction on exportsNo restriction on exports•• Proactive stakeholder communication preProactive stakeholder communication pre--launchlaunch•• Consumer market research Consumer market research –– positive resultspositive results

–– AustraliaAustralia–– SwedenSweden

Immunological castration Immunological castration -- SummarySummary

�� Represents a Represents a safe, effectivesafe, effective and practicaland practical approach to the approach to the control control of boar taintof boar taint in entire (intact) male pigsin entire (intact) male pigs

�� Eliminates the need for surgical castrationEliminates the need for surgical castration to control boar taintto control boar taint�� Prevents the lossesPrevents the losses in growth performance, feed efficiency and in growth performance, feed efficiency and

carcass quality as consequence of surgical castration or slaughtcarcass quality as consequence of surgical castration or slaughter er of lightweight male pigs, and so of lightweight male pigs, and so improves the profitabilityimproves the profitability of pig of pig productionproduction

�� Provides a Provides a welfare friendly alternativewelfare friendly alternative to surgical castrationto surgical castration