Porcine reproductive disease Flashcards
What are the key targets in pig units?
What are normal farrowing rates?
% of sows served that go on to successfully farrow
- –5% Regular return (normal)*
- –2% irregular return (normal)*
- –<1% abortion*
- –<1% endometritis
- –1% NIP (not in pig. Good stockman ship should prevent this )
- –1% cull
- –1% death
- –Total loss 11%
- –Therefore 89% FR
–If you are lower than 89% normally one of the above factors is a problem
–Usually one of these*
Most reproductive failure in the pig is due to
management shortcomings
Discuss post weaning management?
•After weaning sow important to give boar contact (nose to nose contact) from day 1 is essential.
–LH pulsatility
–Must stop day before service
- This should be intensive, for a short time, twice a day.
- Best if sows are brought to the boar.
- Apply back-pressure test (if you put pressure on and she stays standing still she is ready to serve)
- Continuous contact is NOT desirable, habituation
- Sows need to be on ad-lib lactator if they want optimal results to make sure egg quality is high
Discuss post weaning management further?
•Day length is important:
–16 hours of light
–200 Lux (needs high percentage of blue light)
–Important is like this 365 days a year
- Wean-to-Service Interval is usually 5 days. Commonest day for weaning is a Thursday with serving on following monday
- Sows should be served 24 hours after onset of standing heat.
–Gilts 8-12hrs
Discuss post weaning management with regards to insemination?
•Min two inseminations
–24hr intervals (Sows)
–12hr intervals (Gilts)
–Big herds
- Sows will usually need to be moved either <5 days after insemination, OR not until 35 days after insemination (otherwise will interfere with implantation)
- Between 5-35 days the eggs get little hooks on the side and when they go into uterus they hook onto uterus and if you stress her in between this period those hooks can break and she will loose pregnancy
Compare the semens journey to the eggs journey?
- Semen has a long way to travel (sows uterus is very long)
- Survives for 48 hours in uterus
- Capacitation takes 4-6 hours
- Eggs are viable for much shorter time 8-12 hours
- Therefore Semen needs to be waiting for egg this is why we put the early service in to get that semen waiting in there for the egg
- Service timing crucial
- Big herds
Discuss feeding in fertility management?
•Feeding in lactation is important/critical:
–Excessive weight loss will result in longer W-S (weaning to standing) interval and lower numbers born in subsequent farrowing
- Preparing the sow to be re-served occurs from the end of the previous dry period (keep her udder healthy, build her up carefully, max feed intake in 3rd week of lactation is determined by how you built her up in first 10 days)
- 26 d average lactation
How to BCS kids?
•Poor BCS is most common reason for extended W-S
–The loss during lactation more important than end result
- Aim to only lose 0.5 during lactation
- Most sows should be 2-2.5 at weaning
Discuss lactation feeding?
- Feed increased for last 3 weeks of gestation
- Feed reduced on entry to farrowing accommodation
- Sows carefully increased over first 7-10 days of lactation up to maximum feed intake
- Key stockman task
- Some animals will still struggle to maintain body condition
- Density vs Volume
- If you don’t sort this out early you end up selecting against best mothers which are the gilts who will have largest litters but their second parity will let the side down
- Second litter drop
- The quality of the next litter is already being determined
What are the reproductive targets for gilts?
- Puberty by 180 - 210 days of age
- Boar contact from d180
- Mated at 235 -255 days at 135 -150 kg live-weight (either side of this range they will have a shorter life span and less piglets per litter) line dependant
- Mated at 2nd or 3rd recorded heat period. The 1st heat will have a low born alive.
- None on Altresyn before already had a heat
- Farrowing rate +4% better than sow average
- Total born within 0.5 pig / litter of sow herd average
- Successfully re-breed within 6 days of weaning
- Over weight poorer longevity and more expensive to rear
- Under weight higher risk of culling due to poor ability to perform in first lactation
Discuss Altresyn/Regumate?
- Progestagen synchronization product
- Altresyn/Regumate
- Dosed 5ml orally for 18 days – must be same time each day (+/- 30 mins)
- Oestrus around 5 days later
- Very common especially in batch farrowing systems
Discuss autumn infertility?
- Pig originally a season spring breeder
- Typically gilts and young sows affected by autumn infertility. Manifests as:
–Not cycling
–Increased returns
–Abortions
- Caused by short days
- Variation in day night temperature
- Natural in the pig
How can you prepare for autumn infetility?
Be prepared for seasonal infertility
- Increase feed level 0.25-0.5 kg/sow/day
- Increase boar contact 30-60 min/day
- Avoid chilling
Discuss summer infertility?
- Farmer has dug them wallows and filled with water tanker. It is an expectation in outdoor farms to prevent heat stress and sunburn.
- Water quality needs to be maintained needs to keep a healthy mud coat on them.
- Sunburn creates PGF2alpha which damages fertility
It’s all hormones look at this?
Is poor fertility due to infectious disease?
- Sows or boars off-feed
- Sows or boars pyrexic
- Rarely this easy with endemic disease
- Abortions/mummified foetuses
- Irregular returns to heat
- Weak and premature pigs
- High incidence of mummies and/or stillbirths
- Pigs not getting pregnant
- Often just one of the above signs and can be subtle
Name Infectious causes of porcine Reproductive Failure?
•Viruses are the most common infectious cause of reproductive failure in pigs.
•Most commonly:
–PRRSv
–Swine Influenza
–SMEDI
Discuss Porcine Reproductive and Respiratory Syndrome Virus (PRRSv)?
•‘Blue Ear Disease’. Arrived in 1991.
–Blue ears is a sign of septicaemia in the pig and only a small amount of pigs with PRRSv will get blue ears.
- Genotype 1 (Europe), Genotype 2 (USA more aggressive)
- Spread by movement of carrier pigs (airborne spread initially spread around in semen from breeding studs) You can control what people, pigs and vehicles come in to farm to best protect.
- Invades and kills macrophages.
What are the 3 disease statuses of PRRSv?
Negative
–Biosecurity is key
–Check status maintained with serology
Positive, stable
–Sows serologically positive but not shedding virus/viraemic
–Piglets can be weaned virus –ve
–Achieved primarily with vaccination
Positive, unstable
–Sows serologically positive and shedding virus
–Piglets weaned virus +ve – problems in feeding herd
–Restabilisation can be difficult to achieve
Discuss PRRSv control?
Negative - risks
–Stock
–People
–Vehicles
–Airbourne
What is the PRRSv Replacement strategy?
PRRS –ve:
–Buy –ve replacements
–Quarantine min 8wks and check with own sentinels after 5wks
–Strict biosecurity
–Home breed
PRRS +ve
–Isolate and vaccinate replacements
–Vaccination
–Do not serve gilts until >6wks since infection/vaccination
What is SMEDI?
Stillbirth
Mummification
Embryonic Death
Infertility
Syndrome various viral cause: parvo being the main one. Spreading of virus result in sequential fetal death. Most sows are vaccinated for parvo now
Discuss Erysipelas?
- E. rhusiopathiae – ubiquitous
- Excreted via saliva, faeces or urine
- Zoonotic potential (rare)
- Abortions, mummified foetuses, returns to service
- Diagnosis: difficult, diamond lesions on skin
- Tx: sensitive to penicillin
- Control: Vaccination
- Nearly all commercial herds vaccinating
Discuss Brucella suis?
- Not in UK
- Carried by the European hare but never been found in this species in UK (they are tested)
- Causes infertility, abortion and weak piglets, can also cause abscesses
- FSC always cultured at APHA
- Serological cross reactions with Yersinia enterocolitica can be problematic
Look at this picture showing correlation between embryo and foetal death and the consequences?
Picture shows the failure of fertility and what the result of this failure would be depending on the stage of failure.
Outline a breeding herd vaccination schedule?
Suiseng: colostrum boosting vacine
Outline stages of reproductive cycle associated with infertility?
Look at this table for differentiating between infectious and non-infectious causes of reproductive failure?
