Pigs Flashcards
(73 cards)
What is the split of time of weaning, growing and finishing
Weaning from 4-10 weeks
Growing 11-16 weeks
Finishing 17-23 weeks
What two parameters are pig value based on
Weight and P2 fat depth
What temperature indicates a fever in pigs and what group of pigs may have a higher temperature normally
> 40 is fever
Lactating sows have raised temps; up to 39.3
Pig gestation length
116 days
Pig oestrus cycle length and oestrus duration
Cycle = 21 days
Oestrus lasts around 60 hours but very variable
When do female and male pigs reach puberty
Females at 5 months
Males at 8 months
What type of breeding pattern do pigs naturally follow
Seasonal breeders; infertile in summer; fertile in late autumn
How is weaning related to the next oestrus of a sow
Cessation of lactation causes initiation of next oestrus
Get next oestrus 4-6 days after weaning
What is the ideal weaning to service interval
5.5 days
What is second litter drop syndrome
Where sows perform worse at their second litter compared to first. Probably because ova don’t mature properly for second pregnancy during the first one due to physiological stress and low appetitie during growing of large litter
Who is included in the ‘sow herd’
Any currently and potentially reproductively active females; so it DOES include the maiden gilts
What is a rough parity replacement for sows
20%
So 2 in every 10 pigs served should be a gilt
What is the theoretical minimum interval between farrowing
147 days
This would give just under 2.5 litters per year
When does mortality of piglets increase significantly in terms of sow parity
After 5 litters
What pheromone do boars produce
5-alpha androsterone
How many boars to use if doing natural service
Indoor: 1 boar to 20 females
Outdoor: 1 boar to 15 females
When do boars become fertile
10-12 months old
How could we do artificial oestrus synchronisation in pigs
Give 18 days of synthetic progesterone (altrenogest) then when you stop, get oestrus 5-7 days later
Can also just delay by the day after weaning with altrenogest
Why don’t prostaglandins work well in oestrus synchronisation in pigs
Because the CLs are refractory to the action of prostaglandins for most of their lifespan
Why does oestrus start after lactation stops
Get reduction in endrophins from suckling reflex; this reduces prolactin production which releases inhibition on the start of oestrus cycle
What is break through oestrus
When there is a brief cessation of suckling i.e if sow separated from litter during moving, piglets stop suckling if too hot
so get an oestrus occuring during lactation; then won’t be able to have oestrus until 21 days after this so doesn’t follow normal pattern of a heat 5 days post weaning
How does the timing of one oestrus starts in relation to weaning affect the length of the oestrus
The earlier they come into oestrus, the longer it lasts
How long are ova and sperm viable for each
Ova for 8 to 10 hours
Sperm for 48 hours + take 6 hours to capacitate
When is the optimum mating time in relation to ovulation
= 8-10 hours before ovulation
