益生菌复合物对持续热应激肉鸡生长性能、肠道形态和免疫性能的影响

Effects of probiotics complex on growth performance,intestinal morphology and immunity of broilers under continuous heat stress

文章旨在评估益生菌复合物对持续热应激肉鸡生长性能、肠道形态及血清生化指标的影响。试验选择1日龄平均体重一致的648只商品肉鸡,随机分为3组,每组6个重复,每个重复36只。各组肉鸡在试验前7d饲喂基础日粮,从第8~28天对照组肉鸡饲养的环境温度为(24±1.5)℃,饲喂基础日粮,处理1组肉鸡饲养环境温度为32℃,饲喂基础日粮,处理2组肉鸡饲养环境温度为32℃,饲喂基础日粮+2×10^(6)CFU/kg益生菌复合物。结果:对照组28d肉鸡体重、1~28d平均日增重、采食量和饲料报酬及15~28d饲料报酬均显著高于处理1组(P<0.05),同时,对照组15~28d平均日增重和采食量显著高于处理1组和处理2组(P<0.05)。与处理1组相比,对照组和处理2组肉鸡的死亡率分别显著降低50.63%和32.85%(P<0.05)。处理1组肉鸡十二指肠绒毛高度、绒毛高度/隐窝深度和空肠绒毛高度均表现最低(P<0.05)。处理2组肉鸡回肠绒毛高度、隐窝深度较对照组和处理1组分别显著提高16.10%、23.68%和4.18%、7.62%(P<0.05)。对照组和处理2组肉鸡血清谷胱甘肽过氧化物酶活性和白细胞介素-10浓度显著高于处理1组(P<0.05),但处理1组肉鸡血清肿瘤坏死因子-α、白细胞介素-6和转化生长因子-β1浓度显著高于对照组和处理2组(P<0.05)。结论:在本试验条件下,日粮添加益生菌复合物可以通过提高小肠绒毛高度和血清抗氧化及免疫指标降低肉鸡死亡率及热应激对饲料报酬的负面效应。

This experiment was conducted to evaluate the effects of probiotics complex on growth performance,intestinal morphology and serum biochemical indices of broilers under continuous heat stress.A total of 648 commercial broilers with the same average body weight at 1 d of age were randomly divided into 3 groups with 6 replicates per group and 36 broilers per replicate.Broilers in each group were fed the basal diet 7 days before the experiment.From the 8 th to 28 th day,the ambient temperature of broilers in the control group was(24±1.5)℃,and broilers in the basal diet were fed.The ambient temperature of broilers in the treatment group 1 was 32℃,and broilers in the treatment group 2 were fed the basal diet was 32℃.The broilers were fed basal diet+2×10^(6) CFU/kg probiotics compound.Results:The body weight,1~28 d average daily gain,feed intake and feed reward of broilers in control group were significantly higher than those in treatment group 1(P<0.05),while the average daily gain and feed intake in control group were significantly higher than those in treatment group 1 and 2(P<0.05).Compared with treatment group 1,the mortality of broilers in control group and treatment group 2 was significantly decreased by 50.63%and 32.85%(P<0.05),respectively.Duodenal villus height,villus height/crypt depth and jejunal villus height of broilers in treatment group 1 had the lowest values(P<0.05).Compared with control group and treatment group 1,the villus height and the ratio of villus height to crypt depth in ileum of broilers in 2 groups were significantly increased by 16.10%,23.68%and 4.18%,7.62%(P<0.05),respectively.The serum glutathione peroxidase activity and interleukin-10 concentration of broilers in control group and treatment groups were significantly higher than those in treatment group 1(P<0.05),but the serum concentrations of tumor necrosis factor-α,interleukin-6 and transforming growth factor-β1 of broilers in treatment group 1 were significantly higher than those in control group and treatment groups 2(P<0.05).Conclusions:In this study,dietary probiotics compound can reduce the mortality rate of broilers and the negative effects of heat stress on feed return by increasing villus height in small intestine and serum antioxidant and immune indexes.