REPRODUCTIVE FAILUREREPRODUCTIVE FAILURE

In this lecture you will learn:In this lecture you will learn:

The normal reproductive events that occurThe normal reproductive events that occur--from from mating to mating to farrowingfarrowing..How poor management can result in reproductive How poor management can result in reproductive failure.failure.What “seasonal infertility” is & how to What “seasonal infertility” is & how to minimiseminimise it. it. The infectious causes of reproductive failure.The infectious causes of reproductive failure.How to troubleHow to trouble--shoot and resolve reproductive shoot and resolve reproductive problems.problems.Why sows leave the herd prematurely.Why sows leave the herd prematurely.How to How to minimiseminimise premature sow loss.premature sow loss.

Reproductive targetsReproductive targets

Gestation lengthGestation length 114 days114 daysLactation lengthLactation length 21 days21 daysWeaningWeaning--toto--oestrusoestrus 6 days6 daysTOTALTOTAL 141 days141 daysPotential = 2.6 litters/sow/year (actual 2.2)Potential = 2.6 litters/sow/year (actual 2.2)Average pigs born alive per litter = 11Average pigs born alive per litter = 11

Therefore, piglets/sow/year = 28Therefore, piglets/sow/year = 28

Normal reproductive eventsNormal reproductive events

Fertilization occurs in the oviductFertilization occurs in the oviductThe embryos migrate to the uterus and are The embryos migrate to the uterus and are distributed. By about day 11 they are equally spread.distributed. By about day 11 they are equally spread.Around Day 12, the uterus produces PGF2alpha. If Around Day 12, the uterus produces PGF2alpha. If there are no there are no fertilisedfertilised ova, PG escapes from uterus to ova, PG escapes from uterus to ovarian blood supplyovarian blood supply--causes constriction of arterioles causes constriction of arterioles to the CL…CL regresses.to the CL…CL regresses.If 4+ If 4+ fertilisedfertilised ova are in the uterus, they produce ova are in the uterus, they produce enough enough oestroneoestrone sulphatesulphate (1(1stst pregnancy signal) to repregnancy signal) to re--direct the PG from the CL to the uterus...CL remains direct the PG from the CL to the uterus...CL remains to produce progesteroneto produce progesteroneCL is not receptive to PGs before Day 12.CL is not receptive to PGs before Day 12.

Normal reproductive eventsNormal reproductive events

Second signal for pregnancy occurs at 15Second signal for pregnancy occurs at 15--30 days 30 days postpost--mating.mating.OestrogenOestrogen ((oestroneoestrone sulphatesulphate from embryos) is from embryos) is involvedinvolved--mechanism unclear.mechanism unclear.CLsCLs are selfare self--supporting for first 14 days gestation.supporting for first 14 days gestation.After this, they require support from the pituitary After this, they require support from the pituitary through LH.through LH.Failure of maintenance of Failure of maintenance of CLsCLs at this stage could at this stage could result from inadequacy of 2result from inadequacy of 2ndnd signal (embryo removal) signal (embryo removal) or lack of LH receptors on the or lack of LH receptors on the CLsCLs (seasonal (seasonal infertility). infertility).

PregnancyPregnancy

Implantation from Day 10Implantation from Day 10--28.28.FoetalFoetal calcification at about 30 dayscalcification at about 30 daysFoetalFoetal immunocompetenceimmunocompetence by 70by 70--75 75 daysdaysDuration of pregnancy 115 daysDuration of pregnancy 115 days

FarrowingFarrowing

At about 112 days At about 112 days foetalfoetal pituitary pituitary releases ACTHreleases ACTHStimulates Stimulates foetalfoetal adrenal to produce adrenal to produce glucocorticoidsglucocorticoidsStimulates release of PGF2Stimulates release of PGF2ααFollowed by Followed by luteolysisluteolysis, a fall in , a fall in progesterone, a rise in progesterone, a rise in relaxinrelaxin, , oestrogenoestrogen and uterine contractionsand uterine contractions

Reproductive failureReproductive failure

normal return to normal return to oestrusoestrus (18(18--24 days)24 days)delayed return to delayed return to oestrusoestrus (beyond 25 days)(beyond 25 days)abortionabortionpseudopseudo--pregnancypregnancyfailure to failure to farrowfarrowmummified mummified foetusesfoetusesstillbirthsstillbirthssmall litter sizesmall litter sizeabnormal pigletsabnormal pigletsdecreased neonatal survival.decreased neonatal survival.

95%+ of reproductive problems are 95%+ of reproductive problems are nonnon--infectious!infectious!

Is it conception failure?Is it conception failure?Is it pregnancy loss?Is it pregnancy loss?How can you tell?How can you tell?

95%+ of reproductive problems are 95%+ of reproductive problems are nonnon--infectious!infectious!

Is it conception failure?Is it conception failure?Regular returns to service Regular returns to service Regular:irregular returns > 2.5:1Regular:irregular returns > 2.5:1

Is it pregnancy loss?Is it pregnancy loss?Irregular returnsIrregular returnsPregnant on first RTU check at 25d+Pregnant on first RTU check at 25d+May see abortions (rare in grouped sows)May see abortions (rare in grouped sows)

Conception failureConception failure

Mating managementMating managementUnsupervised Unsupervised matingsmatingsPoor quality AIPoor quality AIMating when sows aren’t on heatMating when sows aren’t on heat

Boar factorsBoar factorsOverOver--useuse--espesp young boars in summeryoung boars in summer

Sow factorsSow factorsSubSub--fertile sows (repeat fertile sows (repeat rtnsrtns, late , late rtnsrtns))

HousingHousingMixing postMixing post--matingmatingOverOver--crowdingcrowding

Pregnancy lossPregnancy loss

Summer infertilitySummer infertilityMixing of sows postMixing of sows post--matingmatingAutumn abortionsAutumn abortionsInfectious causesInfectious causes

2 minute 2 minute quizzquizzFarrowing rate 2000: Farm 1

0

20

4060

80

100

Jan

Mar

May July

Sept

Nov

Month mated

Farr

owin

g ra

te (%

)

Gilts (pens)

Sows (stalls)

Q1. Define “farrowing rate”.

Q2. Comment on the effect of parity, season and housing on farrowing rate.

Q3. How would you determine if the low farrowing rate was due to conception failure or pregnancy loss?

Summer/seasonal infertilitySummer/seasonal infertility

ShortShort--day breedersday breedersInfluenced mainly by day length Influenced mainly by day length (through(through melatoninmelatonin))SEASONAL BREEDERSSEASONAL BREEDERSInfluenced by feed availability (may Influenced by feed availability (may “shut“shut--down” when feed is scarce).down” when feed is scarce).OPPORTUNISTIC BREEDERSOPPORTUNISTIC BREEDERS

European Wild BoarEuropean Wild BoarRut (mating season)Rut (mating season)FarrowingsFarrowings (1 litter (1 litter per year)per year)LactationalLactationalanoestrus until anoestrus until weaningweaningNonNon--breeding breeding seasonseason

Late autumn/early winter Late autumn/early winter SpringSpring

Lactate for 3Lactate for 3--4 months 4 months with gradual weaningwith gradual weaning

Summer/autumnSummer/autumn

Major influences and how we Major influences and how we modify themmodify them

Day lengthDay length--indoor housing filters indoor housing filters lightlightBoar contact Boar contact Feed availabilityFeed availabilityAbrupt weaningAbrupt weaning

Classic signs of seasonal infertility are;Classic signs of seasonal infertility are;

MidMid--summer to early autumn (Wks 1summer to early autumn (Wks 1--16)16)Delayed pubertyDelayed pubertyDelayed return to service postDelayed return to service post--weaningweaningDifficulty in detecting Difficulty in detecting oestrusoestrusSows conceive & embryos are present up to 20dSows conceive & embryos are present up to 20dIncreased irregular (25Increased irregular (25--35 d) returns35 d) returnsAbortionAbortionNIP’sNIP’s (Phantom pregnancy)(Phantom pregnancy)In some cases, a reduced litter sizeIn some cases, a reduced litter sizePoor appetite in lactationPoor appetite in lactation

A major part of the storyA major part of the story--mechanisms of 30mechanisms of 30--day returnsday returns

Sows mated in summer/autumn conceiveSows mated in summer/autumn conceiveEmbryos are present for a short timeEmbryos are present for a short timeDisruption to 2Disruption to 2ndnd signal for pregnancysignal for pregnancy--mediated through oestrone sulphate??mediated through oestrone sulphate??CL regresses…Within 1 week of CL regresses…Within 1 week of implantation, they die and the whole implantation, they die and the whole litter is lostlitter is lostReturns at 25Returns at 25--35 days after mating35 days after mating

Key Reproductive EventsKey Reproductive Events

blastocyst Implanted embryo (implantation 11-23 days)Event

Days

Return date if event fails

0 12-14 15-30 21 42 115service

Signal 1 Signal 2

Skeletal calcification

35 70

Immune competence

Aborts post day 35

Death of embryos day 17-35

….irregular returns

What factors influence seasonal What factors influence seasonal infertility?infertility?

Seasonal Infertility is an inherent Seasonal Infertility is an inherent pattern for litter survivalpattern for litter survivalSocial interactionsSocial interactions--pheromonespheromonesAmbient temperatureAmbient temperatureFeeding levelFeeding level--insulin interaction with LHinsulin interaction with LHBoar exposureBoar exposure

Causes of summer and seasonal infertility:Causes of summer and seasonal infertility:

SummerSummerHeat stress on gilt and sow appetiteHeat stress on gilt and sow appetiteHeat stress on Heat stress on oestrusoestrus cyclingcyclingHeat stress on working boarsHeat stress on working boars--fertility, libidofertility, libido“Heat stress” is variable. Below 27 “Heat stress” is variable. Below 27 ooCC isisrecommended, but observed heat stress is recommended, but observed heat stress is best best –– panting, poor appetite, aggression.panting, poor appetite, aggression.

............

Causes of summer and seasonal infertilityCauses of summer and seasonal infertility

SeasonalSeasonalArtifact of being a seasonal breederArtifact of being a seasonal breeder--less litters to less litters to

be born in winter when feed supply is lowbe born in winter when feed supply is lowIncreasing day length the triggerIncreasing day length the trigger--reduces pituitary reduces pituitary

support (LH) for support (LH) for CLsCLs post day 14.post day 14.Extremely variable between piggeries and from Extremely variable between piggeries and from

week to week within a piggeryweek to week within a piggeryGroup housed sows more affected than stalled Group housed sows more affected than stalled Social interaction may have negative effects Social interaction may have negative effects

Do’s and Don’ts during summer:Do’s and Don’ts during summer:

DO undertake regular stimulation of gilts using DO undertake regular stimulation of gilts using a boar in the pena boar in the pen

DO keep gilts, sows and boars as cool and DO keep gilts, sows and boars as cool and uncrowdeduncrowded as possible. as possible.

DO check for 3 week return using a boar ALL DO check for 3 week return using a boar ALL THE TIMETHE TIME

DO practice good mating technique on standing DO practice good mating technique on standing oestrusoestrus, detected twice a day, detected twice a day

DO increase lysine in lactation diet to 1DO increase lysine in lactation diet to 1--1.2%1.2%

Do’s and Don’ts during summer:Do’s and Don’ts during summer:

DON’T crowd gilts (>1.5 mDON’T crowd gilts (>1.5 m22), weaned sows and ), weaned sows and pregnant sows (both >2.0 mpregnant sows (both >2.0 m22))

DON’T mix weaned or pregnant gilts and small DON’T mix weaned or pregnant gilts and small sows with larger sows sows with larger sows

DON’T overwork boars DON’T overwork boars –– gilt boars 2gilt boars 2--3 3 services, older boars 3services, older boars 3--4 services) 4 services)

DON’T have more than 10% of the lactation DON’T have more than 10% of the lactation feeders empty each morningfeeders empty each morning

ALARMS!ALARMS!

ALWAYS conduct 3 week return checks using a ALWAYS conduct 3 week return checks using a boar/v.boar in stalls and pens boar/v.boar in stalls and pens

-- first check for correct 3 week return first check for correct 3 week return detection practice. THEN……detection practice. THEN……

-- If regular returns are increasingIf regular returns are increasingcheck on check on -- boar fertility/semen quality boar fertility/semen quality

-- standing heat mating ?standing heat mating ?-- Improve cooling systemImprove cooling system-- OvercrowdingOvercrowding

ALARMS! (cont.)ALARMS! (cont.)

If irregular returns are increasingIf irregular returns are increasingcheck on the stressors during pregnancy :check on the stressors during pregnancy :

–– too hot? too dry? Wet skin coolstoo hot? too dry? Wet skin cools-- too crowded? too crowded? -- mixing or movement postmixing or movement post--mating ?mating ?-- Evidence of disease?Evidence of disease?

Infectious causes of reproductive Infectious causes of reproductive failurefailure

LeptospirosisLeptospirosis-- pomonapomona, , bratislavabratislava,,Parvovirus, (PCV2?)Parvovirus, (PCV2?)Fever Fever -- erysipelaserysipelasCystitisCystitisEndometritisEndometritisMenangleMenangle virusvirusEncephalomyocarditisEncephalomyocarditis virusvirusPorcine Porcine myocarditismyocarditis virusvirus

ParvovirusParvovirusFoetalFoetal mummification evident mummification evident -- infection infection post 30 dayspost 30 daysFoetalFoetal death at all stages possibledeath at all stages possibleInfection before Infection before immunocompetenceimmunocompetenceVaccination Vaccination –– gilts only & boars (transmit in gilts only & boars (transmit in semen)semen)Diagnosis: Diagnosis: foetalfoetal heart serum/thoracic heart serum/thoracic fluids, PPV fluids, PPV haemagglutinationhaemagglutination Inhibition, Inhibition, virus isolation, HA on virus isolation, HA on foetalfoetal tissuetissue

LeptospiraLeptospira interogans interogans pomonapomona, (, (tarrasoviitarrasovii, , bratislavabratislava, , hurstbridgehurstbridge))Late term abortion, weak pigs, stillbirthsLate term abortion, weak pigs, stillbirthsMummification uncommonMummification uncommonAbortion follows infection and Abortion follows infection and bacteraemiabacteraemiawithin 1within 1--4 weeks4 weeksDxDx: Serology x2, PCR, : Serology x2, PCR, foetalfoetal histohisto, placenta, placentaTetracyclinesTetracyclines in feed 800ppm for 10 days or at in feed 800ppm for 10 days or at 40mg/kg for 340mg/kg for 3--5 days. Take care with residues.5 days. Take care with residues.VaccinationVaccination

CystitisCystitis

E coli, E coli, EubacteriumEubacterium suissuisPoor hygiene, recumbent sows, older parities, Poor hygiene, recumbent sows, older parities, “dog“dog--sitting”, low water intake/availabilitysitting”, low water intake/availabilityStall housing with poor drainage Stall housing with poor drainage Profuse urinary dischargeProfuse urinary dischargeblood in urineblood in urinepoor prognosispoor prognosisPenicillin, Penicillin, amoxycillinamoxycillin, , trimethoprimtrimethoprim--sulphasulpha, , tetracyclinestetracyclines

Vaginal dischargeVaginal discharge

Vaginal or uterineVaginal or uterineE coli, E coli, StaphsStaphs, , StrepsStrepsContamination of sows at mating or Contamination of sows at mating or farrowingfarrowingmay be venereal?may be venereal?also associated with naive giltsalso associated with naive giltsdischarging sows infertiledischarging sows infertile

TreatmentTreatment--cullcull

““MenangleMenangle virus”virus”

ParamyxovirusParamyxovirusFoetalFoetal deathdeathFoetalFoetal malformationmalformationAssociated with flying foxesAssociated with flying foxesZoonoticZoonotic possibilitypossibility

DX: Serology, virus isolationDX: Serology, virus isolation

EncephalomyocarditisEncephalomyocarditis virusvirus

NSW NSW -- not Victoria or not Victoria or QldQld..Linked to rodent populationsLinked to rodent populationsDisease of rats, multiplied up by miceDisease of rats, multiplied up by miceStillbirths in litters, Stillbirths in litters, myocarditismyocarditis in in suckers & suckers & weanersweaners. High mortality in . High mortality in young pigs. Older pigs young pigs. Older pigs subclinicalsubclinicalDxDx: serology, : serology, histopathhistopath

Porcine Porcine myocarditismyocarditis virusvirus

Unknown aetiologyUnknown aetiology--parvoparvo--virus/PCV2virus/PCV2--likelikeIncreased stillbirths, mummies, preIncreased stillbirths, mummies, pre--weaning deathsweaning deathsOccurred in NSW on 2 linked farms in Occurred in NSW on 2 linked farms in 20032003

Diagnostic principlesDiagnostic principles

Serology: paired or get plenty (20)Serology: paired or get plenty (20)FoetalFoetal fluids fluids -- thoraxthoraxHistopathHistopath-- foetusfoetus and placentaand placentaVirus isolation or HA on fresh tissueVirus isolation or HA on fresh tissueRecord analysisRecord analysis-- season and parityseason and parityResponse to vaccinesResponse to vaccines

Quick Quick QuizzQuizz

1. What are the key “symptoms” of 1. What are the key “symptoms” of seasonal infertility?seasonal infertility?2. How would you differentiate this 2. How would you differentiate this from poor mating practice?from poor mating practice?3. List 5 things you would recommend 3. List 5 things you would recommend the farmer do to the farmer do to minimiseminimise the effects the effects of seasonal infertility.of seasonal infertility.

Sow lossSow loss

Targets:Targets:Deaths <3Deaths <3--5%5%Euthanasia <4%Euthanasia <4%Most (40%) occur around Most (40%) occur around farrowingfarrowing

Risk factorsRisk factorsHerd size;Herd size;Housing systems (bloat and urinary tract Housing systems (bloat and urinary tract infections tend to be more frequent in stalls);infections tend to be more frequent in stalls);Management systems (mortality rates Management systems (mortality rates increase as lactation lengths decrease);increase as lactation lengths decrease);Nutrition;Nutrition;Season (deaths are usually higher at times of Season (deaths are usually higher at times of thermal stress);thermal stress);Culling policies (the rate at which sick sows Culling policies (the rate at which sick sows are are euthanasedeuthanased). ). Parity (bladder and kidney infections occur Parity (bladder and kidney infections occur more frequently in older sows/leg problems more frequently in older sows/leg problems occur more commonly in younger stock)occur more commonly in younger stock)

Sow diseasesSow diseases

Big killers: Big killers: Heat at point of Heat at point of farrowingfarrowingPost Post farrowingfarrowing infectioninfectionUlcerUlcerGastric accidentGastric accidentCystitisCystitisLameness/downer/destructionLameness/downer/destruction

Post Post farrowingfarrowing diseasedisease

MastitisMastitisddxddx agalactiaagalactiausually isolated glandusually isolated glandascending infectionascending infectionmay involve several glandsmay involve several glandsconsequence of asynchronous lactation and consequence of asynchronous lactation and engorgementengorgement

Post Post FarrowingFarrowing

MetritisMetritis: : ascending infectionascending infectionwithin 24 hours post within 24 hours post farrowingfarrowing

Thin sowsThin sowsShoulder soresShoulder sores

Sows: Clinical diseasesSows: Clinical diseases

ProlapseProlapse: rectal or vaginal: rectal or vaginalLameness: medial claw injuryLameness: medial claw injuryOCDOCDepiphysiolysisepiphysiolysis femoral headfemoral headerysipelaserysipelas

MinimiseMinimise deathsdeathsMinimiseMinimise excitement and noise around feeding;excitement and noise around feeding;Maintain frequency of feeding (Maintain frequency of feeding (ieie do not skip feeds do not skip feeds on weekends);on weekends);Intermittent spray cooling in summer during Intermittent spray cooling in summer during pregnancy/drip cooling during lactation;pregnancy/drip cooling during lactation;Do not allow sows to get overly fat;Do not allow sows to get overly fat;Proper ventilation;Proper ventilation;Ensure adequate water availability and flow rates Ensure adequate water availability and flow rates (greater than 1.5L/min);(greater than 1.5L/min);Maintain floors (correct drainage problems, reMaintain floors (correct drainage problems, re--surface abrasive floors);surface abrasive floors);Maintain hygiene (do not allow stalled animals to lie in Maintain hygiene (do not allow stalled animals to lie in their own their own faecesfaeces and urine);and urine);Attention to pen and shed maintenanceAttention to pen and shed maintenance

Another “quickie”Another “quickie”

This is a weaned sow. She was weaned after a 4 week lactation.

Q1. What is the lesion on her shoulder?

Q2. What are 2 major risk factors for this lesion?

Q3. How would you manage a sow like this to prevent this re-occurring?

In this lecture you should have In this lecture you should have learnt:learnt:

The normal reproductive events that occurThe normal reproductive events that occur--from mating to from mating to farrowingfarrowing..How poor management can result in How poor management can result in reproductive failure.reproductive failure.What “seasonal infertility” is. What “seasonal infertility” is. The infectious causes of reproductive failure.The infectious causes of reproductive failure.How to troubleHow to trouble--shoot and resolve shoot and resolve reproductive problems.reproductive problems.Why sows leave the herd prematurely.Why sows leave the herd prematurely.How to How to minimiseminimise premature sow loss.premature sow loss.