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

Abstract

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.

Enrichment with Lucerne Hay Improves Sow Maternal Behaviour and Improves Piglet Survival

“…This relationship was reversed for sows in the lucerne treatment, with primiparous sows (n = 16) displaying an increased rate of successful mating (81%) and the multiparous sows (n = 13) showing a decreased rate (60%), relative to the controls. Feeding legume fibre (lupins) prior to mating is beneficial for oocyte maturation in primiparous sows [56], and can explain the improvement in mating success rate for these animals. The 30% decrease in mating success seen in the multiparous sows given lucerne is consistent with a suboptimal lactation diet, possibly related to the dilutive effects of fibre on nutritional intake [57,58], but it is not clear why this effect would not also apply to the primiparous sows that are under more severe metabolic challenges during lactation.…”

The role of dietary fibre in pig production, with a particular emphasis on reproduction

“…Gilts fed a high fibre diet (containing 50% USBP) from d 1 to 19 of their third post-pubertal oestrous cycle had more oocytes that reached MII following 46 h of IVM culture compared to control gilts [ 41 ]. Additionally, pre-pubertal gilts fed a high fibre lupin diet from 3 wk before puberty stimulation until d 19 of their first oestrous cycle had almost nine times more MII oocytes than gilts fed the low fibre control diet and more than five times more MII oocytes than the gilts fed the medium fibre bran diet [ 42 ]. Despite the alterations in oocyte quality, dietary fibre does not appear to affect ovulation rate [ 42 – 45 ].…”

“…Additionally, pre-pubertal gilts fed a high fibre lupin diet from 3 wk before puberty stimulation until d 19 of their first oestrous cycle had almost nine times more MII oocytes than gilts fed the low fibre control diet and more than five times more MII oocytes than the gilts fed the medium fibre bran diet [ 42 ]. Despite the alterations in oocyte quality, dietary fibre does not appear to affect ovulation rate [ 42 – 45 ].…”

“…Such reproductive benefits were also observed following consumption of alternative fibre sources. Embryo survival was higher on d 27-29 after mating in gilts fed a lupin-based diet prior to insemination [ 41 , 42 ]. Feeding a high fibre diet prior to mating also improved the outcome of pregnancy.…”

“…Another potential mechanism involves changes in concentrations of metabolites in plasma and subsequently ovarian follicular fluid. For example, circulating levels of insulin-like growth factor-1 (IGF-1) and leptin were lower in high fibre fed pigs [ 42 ]. Pigs fed a high lipid, high fibre diet had lower plasma concentrations of β-hydroxybutyrate, leptin, glucose, insulin and urea in one study [ 68 ].…”