Fibre for gilts raises litter size
FEEDING gilts high fibre diets during the rearing stage increases early embryo survival and litter size.
The findings are based on work at SAC Aberdeen, which has been trying to find out why feeding diets high in fibre to breeding sows improves reproductive performance.
Researcher Vicki Glasgow said litter size was influenced by two main factors – ovulation rate and embryo survival. Work done previously had found no increase in ovulation rate in gilts fed high fibre diets. This latest trial studied the effect of feeding high fibre diets on embryo survival.
Seventy two gilts of lean genotype from Newsham Hybrids were allocated to one of two diets at 138-days-old and housed in groups of six. Diets were a cereal based feed or a high fibre ration including 50% molassed sugar beet pulp.
For the first eight weeks, high fibre gilts were fed ad-lib with cereal gilts pair fed to the same daily energy intake. All gilts were served by AI and culled five to six days later for recovery of reproductive tracts.
"Gilts on the high fibre diet had higher embryo yields and higher cell counts at the same development stage," said Miss Glasgow. "This suggests that fibrous diets fed over the rearing stage may improve early embryo vitality.
"This work, and that of earlier studies, shows that feeding diets containing 20% fibre to gilts in the rearing stage, 20% in gestation, and 10% in lactation may see improvements in litter size of half a piglet a litter." *