Effects of L-Theanine on Performance and Immune Function of Yellow-Feathered Broilers
The purpose of this study was to investigate the effects of L-theanine on the performance and immune function of yellow-feathered broilers. A total of 690 one-day-old yellow-feathered broilers were randomly divided into 6 groups with 5 replicates per group and 23 birds per replicate. The groups were divided into a control group (non-antibiotic group) , an antibiotic group (added 10% of colistin sulphate, 200 mg/kg during 1 to 3 weeks, 150 mg/kg during 4 to 7 weeks) , 4 different levels of L-theanine ( 100, 200, 400 and 800 mg/kg) groups. The trial lasted for 49 days. Performance, immune organ indices, intestinal secretory immunoglobulin A (slgA) , serum lysozyme activity, antibody level and immunocytokine contents were investigated. The results showed as follows-. 1) during the period of 1 to 3 weeks, the body weight gain of 100 mg/kg L-theanine group was significantly lower than that of the other groups (P <0. 05) , the bursa of fabricius index of 100, 200 and 800 mg/kg L-theanine groups was significantly lower than that of the control group (P <0.05). The contents of intestinal slgA and serum interferon-r (IFN-7) in L-theanine groups were significantly higher than those of the control group (P<0.05). 2) During the period of 4 to 7 weeks, there were no significant differences in the performance, immune organ indices and intestinal slgA content among L-theanine groups, control group and antibiotic group. Serum interleukin-2 (IL-2) content of 100, 200 and 400 mg/kg L-theanine groups was significantly higher than that of the control group (P<0.05) , and serum IFN-7 content of 200 and 400 mg/kg L-theanine groups was significantly higher than that of the control group (P<0.05). 3) During the entire experimental period, there were no significant differences in serum lysozyme activity and interleukin-4 (IL-4) content among all groups (P>0. 05). Lower anti-Newcastle disease virus (NDV) titers of 100 and 200 mg/kg L-theanine groups were found on day 6 post primary immunization compared with the control group and antibiotic group (P< 0.05), but higher anti-bovine serum albumin (BSA) antibody levels of 100, 200 and 800 mg/kg L-theanine groups were found on day 14 post primary immunization compared with the control group (P < 0. 05) , and there were no differences in anti-NDV titers and anti-BSA antibody level among all groups during the other periods (P >0. 05). In conclusion, there were no significant differences in performance and immune organs indices during the later trial period of broilers supplemented L-theanine, which indicate that L-theanine is safe for broilers. And the L-theanine supplementation can bring about higher intestinal slgA content of early experimental period, serum IL-2 content of later experimental period and serum IFN-7 content of entire experimental period, so the immune function of broilers are enhanced by the diets supplemented L-theanine. [Chinese Journal of Animal Nutrition, 2012, 24(10) : 1946-1954]
L-theanineyellow -feathered broilersperformanceimmune function
国家科技期刊平台
NSTL
万方数据
维普
