Grape Pomace and Ferulic Acid Improve Antioxidant Enzyme Activity and Gut Histomorphometry in Heat-Stressed Finishing Pigs

Given the restrictions on animal growth promoters, alternative plant-based additives—particularly those rich in phenolic compounds, such as agro-industrial by-products—have been explored. These additives help to mitigate heat stress, which negatively affects productivity by impacting intestinal health and antioxidant status. This study evaluated the effects of individual and combined supplementation of ferulic acid (FA) and grape pomace (GP) on antioxidant enzyme activity, as well as intestinal histomorphometry, in finishing pigs under heat stress. Forty Yorkshire × Duroc pigs were randomly assigned to four treatments: control, 25 mg/kg FA, 2.5% GP, and MIX (FA + GP). FA supplementation increased intestinal villus height, while GP increased villus width in the duodenum and jejunum (p < 0.05). Antioxidant enzyme activity (SOD, CAT, and GPx) increased in pigs supplemented with GP (p < 0.05). These results suggest that GP and FA have potential as functional additives in monogastric diets, improving intestinal health and muscle antioxidant status and contributing to growth modulation.