Impact of maternal antioxidant supplementation on ovarian development in prepuberal Iberian pig offspring

A large percentage of breeding sows are culled before replacement costs are covered. Management and feeding are important factors affecting the performance of replacing gilts. Specifically, an optimal redox status has been linked to better fertility. Current research highlights the importance of neonatal criteria and age at puberty as factors in the gilt selection. Maternal antioxidant supplementation has benefits on the litter's performance, but there is scarce data on its effect on the future breeder. The aim of the study is to evaluate the effects of maternal supplementation with vitamin E (VE) and/or hydroxytyrosol (HXT) on prepuberal ovarian characteristics in Iberian pig offspring. Fifty Iberian sows were supplemented from day 85^th of gestation until weaning with 30 or 100 mg/kg VE and 0 or 1.5 mg/kg HXT, resulting in four groups: VE30HXT0, VE100HXT0, VE30HXT1.5, VE100HXT1.5. At 110 d-old, 10 to 12 daughters were selected from each group to study weight, redox status and ovary histological measures and differences of selected gene expression patterns. Results showed that gilts with high VE had higher superoxide dismutase activity and malondialdehyde levels (P < 0.05 for both). Furthermore, total and oxidized glutathione showed a VE*HXT interaction, with VE100 gilts having the lowest activity values. These results imply a higher oxidative status with high VE supplementation. However, VE100 gilts also showed larger ovarian surfaces (P < 0.05 for planes 1, 6 and 10) and a lower proportion of small follicles (P < 0.05), which could mean a more proximal state to puberty of VE100 gilts. Furthermore, HXT effects on the ovarian surfaces and ovarian gene expression patterns were modulated by maternal parity. Thus, in gilts from primiparous mothers supplemented with HXT, plane 6 and plane 10 ovarian surfaces were smaller, and the expression of certain genes (FSHR, RUNX1 and IGF1) were lower than those from primiparous sows without supplementation (P < 0.05 for all the interactions). In conclusion, dietary antioxidant supplementation during perinatal period affected ovary development during prepuberal stages of the progeny, with different effects according to maternal parity.