The effect on litter size of increased feed intake during the oestrus period in the sow

Abstract
SUMMARY A field trial was conducted at 13 centres to investigate the effect of increasing feed intake on the day of mating on litter size of sows. From weaning to mating, control animals received 1·8, 2·3 or 2·7 kg food/day depending on the managemental procedure of the centre. Flushed animals were fed in the same way except on the day of mating when their feed allocation was doubled. Flushing did not significantly affect litter size when the overall results of all centres were considered (447 sows). Results for individual centres were also examined. A significant response to ‘flushing’ was obtained at only one of the 13 centres, where increasing feed intake from 2·7 to 5·4 kg on the day of mating significantly (P < 0·05) increased litter size by 1·3 ±0·52 pigs born.