Effects of

Introduction: This study investigated the effects of Methods: A total of 160 fifteen-day-old Arbor Acre broilers were randomly allocated to five dietary treatment groups, receiving a basal diet supplemented with AOE at 0, 250, 500, 1000, or 2000 mg/kg for 28 days. Serum and intestinal (duodenum, jejunum, ileum) samples were collected at 28 and 42 days of age for analysis. Results: The results showed that dietary AOE supplementation could significantly improve the antioxidant capacity of broilers: at 42 days of age, it increased serum CAT activity and decreased MDA concentration; it also enhanced the activity of GSH-Px, SOD, CAT and T-AOC in the intestine, and reduced ileal MDA content. In terms of immune function, AOE increased serum IL-2, IL-1β, IL-6, TNF-α levels at 28 days of age and Newcastle disease antibody titers at both 28 and 42 days of age. At the molecular level, AOE upregulated the mRNA expression of CAT, SOD, GSH-Px in the duodenum and ileum at 28 days of age and increased the mRNA expression of iNOS in the intestine, consistent with the elevated serum NO content and iNOS activity. The regulatory effects of AOE were more significant at 42 days of age, and the appropriate supplementation level was 1000 mg/kg. Conclusion: In conclusion, AOE can be used as a natural green feed additive to enhance the antioxidant capacity and immune function of broilers, providing experimental basis for its application in broiler production.