饲粮中添加不同水平溶菌酶对黄羽肉鸡生长性能、免疫功能、抗氧化能力、肠道短链脂肪酸含量及微生物区系的影响OA

This experiment was conducted to investigate the effects of dietary supplementation with different levels of lysozyme on growth performance,immune function,antioxidant capacity,intestinal short-chain fatty acids contents and microbial flora of yellow-feathered broilers.A total of 450 healthy 1-day-old yellow-feath-ered broilers with an initial average body weight of approximately 31.7 g were randomly divided into 3 groups with 10 replicates per group and 15 broilers per replicate.Broilers in the control group(CON group)were fed a basal diet,while those in the experimental groups were fed the basal diets supplemented with 250(LZ250 group)and 500 mg/kg(LZ500 group)lysozyme(enzyme activity:100 000 U/g),respectively.The experi-mental period lasted for 56 days.The results showed as follows:1)compared with the CON group,the feed-to-gain ratio in the LZ500 group was significantly decreased(P＜0.05).2)Compared with the CON group,the serum contents of immunoglobulin A(IgA),immunoglobulin M(IgM)and immunoglobulin Y(IgY)in the LZ250 and LZ500 groups were significantly increased(P＜0.05),and the serum content of tumor necrosis factor-α(TNF-α)was significantly decreased(P＜0.05);the serum contents of interleukin-1β(IL-1β)and interleukin-6(IL-6)in the LZ500 group were significantly decreased(P＜0.05),while the serum content of interleukin-10(IL-10)was significantly increased(P＜0.05).3)Compared with the CON group,the serum glutathione peroxidase(GPx)activity in the LZ250 and LZ500 groups was significantly increased(P＜0.05),and the serum malondialdehyde(MDA)content was significantly decreased(P＜0.05);the serum superoxide dismutase(SOD)activity in the LZ500 group was significantly increased(P＜0.05).4)Compared with the CON group,the cecal contents of propionic acid,butyric acid and isobutyric acid in the LZ500 group were sig-nificantly increased(P＜0.05).5)Compared with the CON group,the relative abundance of Streptococcus in cecum of the LZ250 and LZ500 groups was significantly increased(P＜0.05),while the relative abundance of Butyricimonas in cecum was significantly decreased(P＜0.05);the relative abundance of Turicibacter in ce-cum of the LZ500 group was significantly increased(P＜0.05).In conclusion,dietary supplementation with 500 mg/kg lysozyme can significantly improve the growth performance,immune function and antioxidant ca-pacity of yellow-feathered broilers,increase the contents of SCFAs in cecum,and alter the cecal microbial composition.[Chinese Journal of Animal Nutrition,2026,38(3):1900-1910]