Effects of different methionine levels on offspring piglets during late gestation and lactation

Maternal dietary supplementation during gestation and lactation improves the health of piglets. The purpose of this study was to determine the effect of different levels of methionine (Met) supplementation in the sows' diet during late gestation and lactation on piglets. Thirty sows were randomly divided into three groups and fed the following diets from day 90 of gestation to day 21 of lactation: (a) control group (a basal diet containing 0.36% Met), (b) 0.48% Met group (a basal diet with additional 0.12% Met), and (c) 0.60% Met group (a basal diet with additional 0.24% Met). On day 21 after farrowing, piglets of average body weight (n = 10 per group) were selected for sample collection. The results showed that the 0.48% Met and 0.60% Met diets significantly lowered the malondialdehyde content in the piglets' serum (P < 0.05). In addition, the glutathione peroxidase content was significantly increased in the 0.48% Met group (P < 0.05) and the total glutathione content was significantly reduced in the 0.60% Met group (P < 0.05) compared to the control group. Furthermore, Met supplementation of the sows' diet was associated with alterations in 37 plasma metabolites in the piglets. In the piglets' intestinal microbiota, the relative abundances of Phascolarctobacterium and Bacteroidetes in the 0.48% Met group were higher than those in the other two groups (P < 0.05). Our results suggest that a diet including 0.48% Met during late gestation and lactation can maintain the health of piglets by increasing the antioxidant capacity and changing the intestinal microbiota composition, but a higher level of Met supplementation may increase the potential risk to piglets.