Porcine reproductive disease Flashcards
1
Q
Key Targets
A
- Indoor pigs are more productive than outdoors
- Aim for 88% farrowing rate
- % of sows served that go on to successfully farrow
- 5% regular return
- 2% irregular return
- <1% abortion
- <1% endometritis
- 1% NIP (not in pig)
- 1% death
- Intervention level for stillbirths is 7%. If higher than this, need to do something about it.*
- Usually due to management shortcomings as the pig is INCREDIBLY fertile.*
2
Q
Postweaning management
A
- After weaning, boar contact from day 1 is essential = LH pulsatility, contact must stop the day before service.
- Service should be intensive, twice a day.
- Best if sows are bought to the boar
- Apply back-pressure test
- Continuous contact the with the boar is NOT desirable - habituation
- Sows on ad-lib lactator diet
- Day length is important in service house:
- 16 hours of light, 200 lux (blue light best) - needs to be like this 365 days a year.
- Wean-to-service interval = 5 days!
Sows should be served 24 hours after onset of standing heat. Gilts should be served 8-12 hours.
3
Q
Inseminations
A
- Minimum of 2 inseminations
- 24 hour intervals (sows) e.g. mon morning and tues morn
- 12 hour intervals (gilts)
Sows usually need to be moved <5 days after insemination, OR not until 35 days else will interfere with implantation.
4
Q
Semen vs Egg
A
- Semen has a long way to travel
- survives 48 hours in uterus
- Capacitation after 4-6 hours
- Eggs are only viable for 8-12 hours
- semen therefore needs to be waiting for the egg - this is why we do the first service.
- service timing is crucial
5
Q
Fertility management
A
- Feeding in lactation important - excessive weight loss leads to longer W-S interval and lower numbers born
- 26-28 day lactation
- BCS is the most common reason for extended W-S interval. Aim is to lose only 0.5 during lactation.*
- Most sows should be 2.5-3.0 at weaning.*
6
Q
Lactation feeding
A
- Feed increased for last 3 weeks of gestation, but feed is reduced on entry to farrowing accomodation
- Sows increased 7-10 days over lactation to maximum feed intake
7
Q
Gilt reproductive targets
A
- Puberty by 180-210 days of age (6 months) - boar contact from 180d
- Mated by 235-255 days at 135-150kg live-weight
- Mated at 2nd or 3rd recorded heat (first heat have poor quality embryo and few born alive)
- Farrowing rate +5%, bettwe than sow average
- successfully re-breed within 6 days of weaning.
Gilts only stop being gilts when served a second time.
8
Q
Factors that affect oestrus
A
- Progestagen synchronisation
- Altresyn/Regumate (progesterone)
- Dosed 5ml orally for 18 days - same time each day
- Oestrus around 5 days later
- Very common in batch farrowing
9
Q
Seasonal Infertility
A
- Autumn infertility - spring breeders (happy to get pregnant from Christmas onwards)
- During autumn, not cycling, increased returns, abortions
- caused by short days, variation in day night temps
- natural phenomenon in the pig
BE PREPARED:
- increased feed level 0.25-0.5kg/sow/day
- increase boar contact 30-60 min/day
- avoid chilling
- There is also a summer infertility - heat stress and sunburn. Outdoor herds need to have water wallows.*
- Pigs are sensitive to sunburn, produces prostaglandins and this causes reduced fertility.*
10
Q
Poor fertility and infectious disease
A
- Sows or boars off-feed, pyrexic
- abortions/ mummified foetuses
- irregular return to heat
- weak/premature piglets
- viruses are most common infectious cause of repro failure in pigs
- PRRSv - MOST IMPORTANT
- Swine influenza
- SMEDI (not common)
11
Q
Porcine Reproductive and Respiratory Syndrome Virus (PRRSv)
A
- Blue Ear Disease (septicaemia)
- Spread by movement of carrier pigs (airborne) - genotype 1 (Europe)
- Invades and kills macrophages
- Many herds endemically affected
- Genetic mutation common - new strains
12
Q
Disease status PRRSv (3)
A
Negative:
- Biosecurity key - strong perimeter, no unauthorised visitors unless disinfected. Check status maintained with serology.
- Risks - stock, people, vehicles, airborne
Positive, stable:
- THIS IS THE MOST COMMON
- serologically +ve, but not shedding
- piglets weaned -ve virus
- achieved with VACCINATION
Positive, unstable:
- serologically +ve and shedding
- piglets weaned virus +ve
- sows might be immunocompromised
13
Q
PRRSv replacement strategy
A
- PRRS -ve
- buy -ve replacements
- quarantine min 8 weeks and check after 5 weeks
- strict biosecurity
- home breed
- PRRS +ve
- Isolate and vaccinate replacements
- VACCINATION
- do not serve gilts until >6 weeks since infection/vaccination
- Buy negative replacement stock
14
Q
Control of PRRSv
A
- Monitoring the positive herd
- PCR - oral fluids, blood, tissue
- Blood - pin prick ear in 30x piglets at weaning, aborted sows, PCR
- Tissue
- foetal thymus
- spleen
- lung
Vaccination is the mainstay!
15
Q
Swine Influenza
A
- Causes poor fertility due to pyrexia
- Included in investigation for high pregnancy failure rates
- H1N1, H1N2, H3N2 most common
- Introduced by people, carrier pigs, birds
-
Diagnosis:
- clinical signs, nasal swabs, serology
-
Control:
- biosecurity
16
Q
SMEDI
A
- Stillbirth, Mummification, Embryonic Death, Infertility - not common
- CAUSES:
- Parvovirus (PPV)
- Teschoviruses (sapelovirus, teschen, talfan)
- Encephalomyocarditis virus (EMCV)
- PCV 2
Transplacental infection of foetus. Abortion is rate, foetuses usually fo to term as no prostaglandin trigger.
26
Q
Erysipelas
A
- E. rhysiopathiae
- excreted in saliva, faeces and urine
- zoonotic potential (rare)!
- aortions, mummified foetuses, returns
- DIAMOND lesions on skin
- diagnosis- difficult
- treatment - sensitive to penicillin
- control - vaccination!
27
Q
Brucella suis
A
- Not in the UK
- Carried by European hare, but never been found in this species in the UK
- causes infertility, abortion and weak piglets, can also cause abscesses
- serological cross reactions with Yersinia enterocolitica can be problematic!
