Effects of silymarin supplementation during transition and lactation on reproductive performance, milk composition and haematological parameters in sows

Silymarin has been shown to be a multiple-functional plant extract having antioxidant, hepatoprotective, hypolipidemic, antihypertensive, antidiabetic and anti-obesity effects. In recent years, the galactagogue effects of silymarin in animals and humans have also been revealed. This research was conducted to test whether dietary inclusion of silymarin during transition and lactation could impact reproductive performance of sows and to explore the underlying mechanisms. From day 108 of gestation to weaning, sows were randomly assigned to receive dietary treatment of silymarin (40 g/day) or not and were designated as control group (CGP, n = 55) or treatment group (TGP, n = 55). The results showed that piglets' average daily gain and average weaning weight were higher in TGP than CGP sows. In comparison with the CGP sows, the TGP sows had higher serum concentrations of catalase (CAT) on day 18 of lactation and glutathione peroxidase (GSH-Px) on day 7 of lactation. The TGP sows had lower concentration of TNF-α on day 7 of lactation and significantly lower concentration of IL-1β on day 18 of lactation than CGP sows. There was significantly higher serum concentration of PRL on day 7 of lactation in sows consuming silymarin than sows from the CGP group. On day 18 of lactation, the protein and urea contents in milk were significantly increased while the serum urea concentration was significantly decreased in TGP sows. In summary, our results indicate that silymarin supplementation during transition and lactation can increase circulating concentrations of PRL transiently, reduce oxidative stress, increase feed intake and enhance protein metabolism, thereby significantly increasing milk yield of sows and subsequently improving growth performance of their offsprings.

Keywords: cytokines; oxidative status; prolactin; silymarin; sow.