CAL: pig production Flashcards
Hallmarks - porcine parvovirus
Litters with dead fetuses of varying sizes, including mummified fetuses, along with stillborn and healthy pigs born to first parity gilts
What are the 9 viruses in pigs that can cause reproductive disease?
IMPORTANT FIVE:
- Aujeszky’s disease (AD) virus or pseudorabies virus (PRV).
- Porcine parvovirus (PPV).
- Porcine reproductive and respiratory syndrome virus (PRRS).
- Classical swine fever virus (CSF) = Hog Cholera
- Swine influenza virus (SI).
ALSO: BVDV BDV Porcine enterovirus (SMEDI) Encephalomyocarditis virus (EMCV) - country/regional
What are short weaning to oestrous intervals (4 days or less) associated with?
longer oestous periods (3 days) and later ovulation –> adjust AI accordingly
What is a long weaning to oestrus intervals (6 days or more) are associated with?
shorter oestrus periods (2 days) and earlier ovulation –> adjust AI accordingly
How does season affect when a sow comes back into oestrous?
Spring: Oestrus tends to occur earlier from January to May than in the Autumn.
Autumn: Oestrus tends to occur later from September to January than in the Spring.
Adjust timings for insemination accordingly
Which parities have the biggest/smallest litters?
- Parities 1 and 2 generally have smaller litters than 3 + parities. Parities 6 + have large litters, more variable piglet birth weights.
- Parities 3 - 5 generally have the ‘best’ piglets (number and quality).
What is the minimum proportion of the pig herd that should be in parities 3-5?
minimum 45%
To maintain the correct parity spread and avoid retaining old sows a replacement rate of what is needed?
40%/year
What is a good indicator of potential litter size?
weaning to service interval
What is the difference in litter size between sows and gilts?
A gilt will have a smaller littersize than a more mature sow. We would normally expect her littersize to be within 1 piglet of the average of the older parity sows, with a maximum difference of 1.5.
