Oocyte maturation and embryo survival in nulliparous female pigs (gilts) is improved by feeding a lupin-based high-fibre diet

Inclusion of high levels of the high-fibre ingredient sugar-beet pulp in pre-mating diets has been shown to increase gonadotrophin concentrations and improve oocyte quality in nulliparous pigs (gilts). This study evaluated the effects of two alternative fibre sources on reproductive performance in gilts. Gilts received one of three diets from 3 weeks before puberty stimulation until Day 19 of the first oestrous cycle: control (39 g kg(-1) fibre), bran (500 g kg(-1) wheat bran, 65 g kg(-1) fibre) or lupin (350 g kg(-1) lupin, 118 g kg(-1) crude fibre). Diet did not affect circulating LH concentrations or ovarian follicle size. However, a higher percentage of oocytes collected from lupin-supplemented gilts reached metaphase II in vitro compared with those collected from bran-fed or control gilts (89 +/- 5% versus 72 +/- 5% and 66 +/- 5%, respectively; P < 0.05). Furthermore, in a second experiment, gilts fed the same lupin-based diet before mating had improved embryo survival (92 +/- 5%) on Day 28 after mating compared with control gilts (76 +/- 4%; P < 0.05). Therefore, feeding a high-fibre diet before mating can improve oocyte quality in gilts without changes in circulating LH, but this effect is dependent on the fibre source.