Abstract: Objective: In order to investigate the effect of dietary methionine supplementation on intestinal development and antioxidant function in growing pigs with intrauterine growth retardation (IUGR). Methods: At postnatal day 21, thirty normal birth weight (NBW) female piglets and sixty same-sex IUGR piglets were weaned. The NBW piglets were allocated to the NBW control (NBW-CON) group, and the IUGR piglets were randomly assigned to the IUGR control (IUGR-CON) and methionine supplementation (IUGR-MET) groups. The piglets were thus distributed across three groups for a 84 d of feeding trial, and each group consisted of six replicates with five piglets per replicate. Results: IUGR-CON pigs exhibited a reduction in villus height (VH) in both the jejunum and ileum, villus surface area in the jejunum, the activities of sucrase and maltase in the ileum, and OCLN mRNA expression in the jejunum when compared with NBW-CON pigs (P < 0.05). Compared with NBW-CON pigs, IUGR-CON pigs had increased malondialdehyde (MDA) content in the jejunum, decreased reduced glutathione (GSH) content and GSH/oxidized glutathione ratio in the jejunum, and superoxide dismutase activity in the ileum (P < 0.05). Dietary methionine supplementation significantly increased VH in the jejunum, maltase activity in the ileum, and OCLN mRNA expression in the jejunum of IUGR pigs (P < 0.05). A higher methionine inclusion alleviated the increased MDA content and the decreased GSH content in the jejunum of IUGR pigs (P < 0.05). Conclusion: Dietary methionine supplementation attenuates lipid peroxidation and improves antioxidant capacity in the intestine, which may be associated with the partially improved intestinal development in IUGR pigs.

Key words: methionine, intrauterine growth retardation, intestinal development, antioxidant function