锌和维生素C对热应激条件下肉鸡生长性能和免疫反应的影响

Effects of zinc and vitamin C on growth performance and immune response of broilers under heat stress

文章旨在研究日粮单独或联合使用锌和维生素C对高温条件下肉鸡生长性能和免疫反应的影响。试验选择320只1d肉仔鸡,根据体重随机分为4组,每组4个重复,每个重复20只鸡。对照组饲喂基础日粮(锌含量为40mg/kg),处理1组在基础日粮中添加60mg/kg锌,处理2组在基础日粮中添加200mg维生素C,处理3组在基础日粮中添加60mg/kg锌+300mg/kg维生素C,试验共开展35d。在试验第21~35天对鸡只进行热应激诱导,即25℃12h,25~34℃3h,34℃6h,34~25℃3h。结果显示:处理组较对照组均显著提高了肉鸡的采食量、体增重(P<0.05),显著降低了料比(P<0.05)。日粮同时添加锌和维生素C组肉鸡采食量和体增重最高(P<0.05)。与对照组相比,日粮添加60mg/kg锌、200mg/kg维生素C或锌和维生素C联合使用的肉鸡脾脏、胸腺和法氏囊重量显著提高(P<0.05)。60mg/kg锌+200mg/kg维生素C和200mg/kg维生素C组较对照组显著提高了新城疫、传染性法氏囊炎和传染性支气管炎的抗体滴度(P<0.05)。与对照组相比,60mg/kg锌+200mg/kg维生素C、200mg/kg维生素C组和60mg/kg锌组显著提高了血液白细胞总数、淋巴细胞和单核细胞占比(P<0.05)。结论:在本试验条件下,日粮单独或联合添加锌和维生素C均可显著改善热应激条件下肉鸡的生长性能和免疫状态。

The purpose of this study was to investigate the effects of dietary zinc and vitamin C alone or in combination on growth performance and immune response of broilers at high temperature.A total of 320 1 d broilers were randomly divided into 4 groups according to body weight,with 4 replicates in each group and 20 chickens in each replicate.The control group was fed a basic diet(zinc content was 40 mg/kg).The group 1 was supplemented with 60 mg/kg zinc,the group 2 with 200 mg vitamin C,and the group 3 with 60 mg/kg zinc +300 mg/kg vitamin C.The experiment was conducted for 35 d.At 21 ~ 35 d,heat stress was induced on chicken,25℃ for 12 h,25 to 34℃ 3 h,34℃,6 h,34 and 25℃ for 3 h.The results showed that the intake and body weight of broilers in the treatment groups were significantly increased(P < 0.05)and the feed ratio was significantly decreased(P < 0.05).The dietary intake and body weight gain of broilers in the group supplemented with zinc and vitamin C were the highest(P < 0.05).Dietary supplementation with 60 mg/kg zinc,200 mg/kg vitamin C or zinc and vitamin C combination significantly increased the weight of spleen,thymus and bursa of chickens compared with the control group(P < 0.05).The 60 mg/kg zinc +300 mg/kg vitamin C and 200 mg/kg vitamin C group significantly increased the antibody titers of Newcastle disease,infectious bursitis and infectious bronchitis compared with the control group(P < 0.05). Compared with the control group,the 60 mg/kg zinc +300 mg/kg vitamin C group,200 mg/kg vitamin C group and 60 mg/ kg zinc group significantly increased the total number of white blood cells,lymphocytes and monocytes(P < 0.05).In conclusion,dietary supplementation with zinc and vitamin C alone or in combination can significantly improve the growth performance and immune status of broilers under heat stress.