Effects of dimethylglycine sodium salt supplementation on growth performance, hepatic antioxidant capacity, and mitochondria-related gene expression in weanling piglets born with low birth weight

: Dimethylglycine sodium salt (DMG-Na), has exhibited excellent advantages in animal experiments and human health. The present study aimed to investigate the effects of dietary supplementation with 0.1% DMG-Na on the growth performance, hepatic antioxidant capacity and mRNA expression of mitochondria-related genes in low birth weight (LBW) piglets during weaning period. Sixteen piglets with normal birth weight (NBW) and sixteen LBW piglets were fed either a basal diet or a 0.1% DMG-Na supplemented diet from age of 21 d to 49 d. Blood and liver samples were collected at the end of the study. The results showed that compared with NBW piglets, LBW piglets exhibited greater (P < 0.05) alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase activities in the serum. LBW decreased (P < 0.05) the activity of glutathione peroxidase, and increased (P < 0.05) the contents of malondialdehyde and H2O2 in liver. DMG-Na supplementation increased (P < 0.05) body weight gain, feed intake, and feed efficiency, decreased (P < 0.05) ALT and AST activities, and reduced the content of H2O2 in LBW piglets. LBW piglets had downregulated (P < 0.05) mRNA expression of thioredoxin 2, thioredoxin reductases 2, and nuclear respiratory factor-1 (Nrf1) in the liver. However, DMG-Na supplementation increased (P < 0.05) mRNA expression of Nrf1 in the liver. In conclusion, DMG-Na supplementation has beneficial effects in alleviating LBW-induced hepatic oxidative damage and changed mitochondrial genes expression levels, which is associated with increased antioxidant enzyme activities and up-regulating mRNA gene abundance.