色氨酸对热应激文昌鸡生长性能、血清生化及抗氧化指标的影响OA

The experiment aimed to investigate the effects of different levels of tryptophan on the growth performance,organ indices,serum biochemistry,immunity,and antioxidant indices of heat-stressed Wenchang chickens.A total of 480 healthy 81-day-old female Wenchang chickens with the same genetic background and similar body weight were randomly divided into five groups with six replicates per group and 16 chickens per replicate.The control group(group 1)was fed a basal diet,while the groups 2 to 5 were fed the basal diet supplemented with 0.09%,0.18%,0.27%,and 0.36%tryptophan,respectively.The pre-test period was 10 days,and the formal test period was 40 days.The results showed that compared with the group 1,the final weight and average daily gain in the group 3 were significantly increased(P＜0.05),and the feed-to-gain ratio in the groups 3 and 4 was significantly decreased(P＜0.05).The dressing percentage in the group 3 and the leg muscle percentage in the groups 2,4 and 5 were significantly increased(P＜0.05).The liver index in the groups 2 and 3,and the spleen index in the group 2 were significantly increased(P＜0.05).The serum total protein(TP)and glucose(GLU)concentrations in the groups 3 and 5,as well as the albumin(ALB)content in the groups 2,3 and 5 were significantly increased(P＜0.05),the uric acid(UA)content in group 3 was significantly decreased(P＜0.05).The serum immunoglobulin A(IgA)content in groups 3 to 5,the immunoglobulin G(IgG)content in the groups 4 and 5,and the immunoglobulin M(IgM)content in the groups 2 to 5 were significantly increased(P＜0.05).The serum superoxide dismutase(SOD)activity and total antioxidant capacity(T-AOC)in the group 3 were significantly increased(P＜0.05),and the malondialdehyde(MDA)content in the groups 2 to 4 was significantly decreased(P＜0.05).The study shows that adding tryptophan supplementation can effectively improve the growth performance,metabolism,immune function,and antioxidant function of heat-stressed Wenchang chickens,and the recommended tryptophan supplementation level is 0.18%.