Average numbers born alive in gilts in MLC recorded herds was 10.3 with numbers born dead 0.7. Numbers born alive in gilt litters is very variable with the average on units varying from less than 9.0 to well over 11.0. Ovulation rate Gilts tend to have low ovulation rates which limits the potential litter size. Ovulation rate is lowest at the first heat and increases up to the third or fourth heat. Feed gilts to appetite for 14 - 21 days before service to get the maximum ovulation rate.
Older gilts tend to have higher ovulation rates when the effect of oestrus number is eliminated.
When to serve Serve gilts at about 140 - 145 kg but not heavier. Gilts should be about 225 days old at service. At service gilts should have a P 2 fat depth of 18 mm - 20 mm. Delay serving until the second or third oestrus. Have gilts on ad libitum feeding for 14 - 21 days before service.