Effect of dietary supplementation with glycitein during late pregnancy and lactation on antioxidative indices and performance of primiparous sows1

The objective of the present study was to investigate the effects of dietary supplementation with glycitein, a major soy isoflavone, during late pregnancy (starting on d 85) and lactation on antioxidative indices and performance in primiparous sows. A total of 227 gilts (Yorkshire × Landrace) were used, and after parturition, piglets were cross-fostered within treatment so that each sow suckled 10 piglets. Gilts were randomly divided into 4 groups on d 85 of pregnancy and thereafter fed the basal diets of gestation or lactation (controls) or those supplemented with 15, 30, or 45 mg/kg diet glycitein. Reproductive performance of the sows, growth of litters, concentration of plasma glycitein, milk composition, and antioxidative indices in sows' plasma and milk, such as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and the content of malondialdehyde (MDA), were measured. Supplementation of the dam's diets with glycitein increased ADG of piglets (linear, P = 0.003) and weaned BW of litters (linear, P = 0.01) and both variables were approximately 10% greater than controls with the 45 mg/kg treatment. The percentage of milk protein was linearly (P < 0.05) increased on d 1 and 7 of lactation, and milk fat content increased on d 7 and 14 (linear, P< 0.05). All other measured indices of performance were unaffected by supplementation with glycitein (P > 0.05). The glycitein concentration in sow's plasma was linearly (P < 0.0001) elevated. During lactation, linear increases occurred in plasma activities of SOD (P < 0.001) and T-AOC (P < 0.05 to P< 0.001), CAT (d 7 to 18 of lactation, P < 0.05) and GSH-Px (d 7 of lactation, P < 0.05), whereas the content of plasma MDA decreased (linear, P < 0.05) throughout lactation with glycitein supplementation. Activities of CAT and T-AOC in milk were not affected by maternal supplementation with glycitein, but increases in SOD on d 18 of lactation (P< 0.001) and GSH-Px in colostrum (P < 0.05) were observed. The content of MDA in milk was decreased (linear, P< 0.05) at all stages of lactation except d 14. Collectively, the results of this study indicate that dietary supplementation with glycitein in sows during late pregnancy and lactation elevated the antioxidative indices, decreased the content of MDA in sow's plasma and milk, improved milk composition, and enhanced the growth performance of the sucking piglets.