This study investigated the effects of resveratrol (RSV) on redox status, jejunal injury, and mitochondrial function in intrauterine growth-retarded (IUGR) weaned piglets. In total, 12 male normal birth weight (NBW) newborn piglets and 24 male IUGR newborn piglets were selected. They were weaned at 26 days of age and then divided into three treatments in a three-week trial: (1) NBW piglets fed a basal diet
(2) IUGR piglets fed a basal diet
(3) IUGR piglets fed a basal diet supplemented with 300 mg/kg RSV. Compared with NBW piglets, IUGR piglets showed decreased growth performance, altered redox status, impaired jejunal morphology, tight junction protein expression, energy production, and mitochondrial oxidative phosphorylation. RSV enhanced antioxidant defense capacity and improved jejunal morphology, ATP generation, and mitochondrial complex I content in IUGR weaned piglets. Dietary RSV supplementation alleviated the IUGR-induced jejunal injury in weaned piglets probably by improving redox status and mitochondrial function, suggesting that RSV has the potential to be a dietary intervention in the regulation of intestinal injury in IUGR piglets.