Feeding diets high in fibre to breeding sows has been found to have a positive effect on reproductive performance. Danske Slagterier (1994) found a significant increase in litter size when sows were fed a diet containing high levels of unmolassed sugar beet pulp (USBP) during pregnancy and lactation. Litter size is influenced by two main factors; ovulation rate and embryo survival. Glasgow et al (1996) found no increase in ovulation rate in gilts fed high USBP diets. This experiment was designed to assess the effect of feeding a high USBP diet on endocrinology and early embryo viability.

The experiment was of a randomised block design incorporating two diets; a cereal based diet (C) and a diet containing 50% unmolassed sugar beet (HF). 72 gilts of lean genotype (Newsham Hybrids) were allocated to treament at 138 days of age, housed in groups of 6 and had liveweight and backfat thickness recorded fortnightly. For the first 8 weeks, HF gilts were fed ad-libitum and C gilts were pair fed to the same daily energy intake. Subsequently, gilts were floor fed isoenergetically at a flat rate of 2.8 kg/d (HF) and 2.3 kg/d (C).