Enhancing Litter Size

Age of gilt at first mating	Gilts should be 210 days
Weight of gilt at first mating	130 -140 kg
Condition of gilt at first mating	20 mm backfat. Feed young gilts well to build up body condition
Which Oestrus in the gilt	Ideally after 2nd oestrus. Note essential to meet batch breeding targets. Mark gilts in each week with a different colour.
Nutrition of gilt from 95 kg	Ad lib feeding up to first mating. Note floor feeding may not provide all gilts in group with ad lib feeding
	With crated gilts it may be necessary to feed twice a day to maximise feed intake prior to first mating
Gestation feeding the pregnant gilt	Limit to a condition score of 3.5 or this will create a second litter size drop
Maximising lactation feed intake	10 kg by day 18 of lactation. Ensure water supply excellent. Ensure farrowing room cool enough.
Weaning to service	Maximise to service increase protein ie fish meal. Possibly keep the sow in the crate and move the piglets and then feed another lactation feed. Do not feed in morning, move and feed in evening
Post-service feeding	Controversial - standard advice 2.5 kg 14% protein 18 MJ 1% lysine for the first 14 days. May be more critical - first 72 hours post-service
Feed quality	Mycotoxins can reduce litter size - increase mummified
Vitamin A injectable	1 million units at time of weaning in sows and 5 days prior to service in gilts (15 days after last recorded heat). Retinol Palmitate used.
Lactation length	Greater than 17 days. Note gilts greater than 19 days.
Parity	Minimise drop-outs from herd to 10% per parity. Parity 3-5 most productive. Replacement rate needs careful management. Ensure herd parity is correct.
Genetics	Heterosis on maternal side may account for 1 pig per litter. Sows with large litters will tend to produce large litters next time. Specific - Meishan effects
Diseases	Ensure vaccination against Parvo is up-to-date. Swine influenza reduces litter size. Enterovirus and other viruses may reduce total born, decrease livebirths, increase mummified and stillbirths
Movement/stress	Move at service or at 28 days once confirmed pregnant. Implantation occurs at approximately 14 days. Do not move or stress females from 7 to 21 days. If crates are used, ensure gilts are accustomed to the crate for at least 10 days prior to mating
Air quality	Air temperature 16-18•C. No draughts.
Boar fertility	Note Swine influenza and heat stress (infection and environment)
AI quality	Note long life extenders may results in bacterial contamination issues. Note boar age also affects litter size.
Mating management	Cross-serving. Two services. Natural service and AI. Good polite stockpeople. Pooled semen . Watch “breeder fatigue”
Light patterns	The service area in particular needs to be well lit and have a 16 hours on and 8 hours off on a time clock. 500 Lux required.
Maximise gilt litter	To maximise lifetime performance. Use gilts as foster mum
Farrowing management	Reduced stillbirths and accurate stillbirths/pre-weaning mortality
Post-service environment	Provide quite post-service management to allow sows to sleep post-mating.