The effect of Alpinia oxyphylla essential oil on growth performance, immune, antioxidant functions and gut microbiota in pigs

, a perennial herb belonging to the Zingiberaceae family, has a long history of traditional medicinal use. The present study evaluated the efficacy of different concentrations of essential oil (AEO) on the growth performance, serum antioxidation capacities, immune function, apparent digestibility of nutrients, and gut microbiota in fattening pigs. A total of 120 pigs were divided into five treatments, with six replicates each and four pigs per replicate. The pigs were fed a basal diet or basal diet with chlortetracycline (CTC) alone or AEO at 250, 500, and 1,000 mg/kg (referred to as groups AEO1, AEO2, and AEO3, respectively) for 35 days, preceded by a 7-day pre-feed period. The results show that there were no statistically significant differences in growth performance for any dose of AEO supplementation. AEO increased L-DLC content, total protein content and the activity of GSH in serum (