不同蛋白质水平日粮添加胍基乙酸对热应激肉鸡生长性能、应激指标及肠道形态的影响

Effects of additional of guanidylacetic acid in different protein levels diets on growth performance,stress index and intestinal morphology of broilers exposed to heat stress

文章旨在评估日粮粗蛋白质水平(正常和正常蛋白水平的90%)和胍基乙酸对肉鸡生长性能、应激指标和肠道形态的影响。试验选择1日龄肉鸡672只,随机分为7组,对照组饲喂正常蛋白水平的基础日粮,处理组肉鸡分别暴露在循环热应激条件下(34℃,8h),分别饲喂正常蛋白水平日粮+0、0.5或1.0g/kg胍基乙酸及90%正常蛋白水平日粮+0、0.5或1.0g/kg胍基乙酸。试验分为3个阶段,共开展42d。结果显示:对照组整个生长期和试验全期肉鸡末重和日增重显著高于热应激组(P <0.05),随着日粮胍基乙酸添加水平的升高,热应激组肉鸡的末重和日增重得到显著改善(P <0.05),对照组较热应激组显著提高了11~24d和25~42d肉鸡的平均日采食量(P <0.05)。对照组较热应激组显著降低了嗜异细胞占比及嗜异细胞与淋巴细胞比值(P <0.05)。对照组T4水平和GSH^Px活性最高(P <0.05)。随着日粮胍基乙酸添加水平的升高,十二指肠绒毛高度、绒毛宽度、绒毛面积及绒毛高度与隐窝深度比值显著提高(P <0.05)。结论 :在循环热应激条件下,肉鸡日粮添加5g/kg胍基乙酸可以改善热应激条件下肉鸡的生长性能、死亡率、抗氧化状态及肠绒毛形态。

The purpose of this study was to evaluate the effects of dietary crude protein levels(90% of normal and normal protein levels)and guanidylacetic acid on growth performance,stress indicators,and intestinal morphology in broilers. We selected a total of 672 broilers aged 1 d, and then randomly divided into 7 groups,control group fed the diet,the basis of normal protein levels poultry processing group were exposed to the circulation heat stress conditions(34℃,8 h),respectively,feeding protein levels normal diet + 0,0.5 or 1.0 g/kg guanidine acetic acid and 90% normal protein levels diet + 0,0.5 or 1.0 g/kg guanidine acetic acid. The experiment was divided into three stages and a total of 42 days were carried out. The result shows :the control group in the whole growing period and test the whole growing period at the end of the chicken and weight significantly higher than that of heat stress group(P < 0.05),with the increase of level of diet guanidine acetic acid added,heat stress group of chickens at the end of the daily gain weight and get improved significantly(P < 0.05),the control group significantly increased in the heat stress group for 11 ~ d 24 and 25 to 42 d chicken average daily feed intake(P < 0.05). Compared with the heat stress group,the control group significantly reduced the proportion of allotropic cells and the ratio of allotropic cells to lymphocytes(P < 0.05). The T4 level and gsh ~ px activity in the control group were the highest(P < 0.05). The villi height,villi width,villi area and the ratio of villi height to crypt depth in the duodenum increased significantly with the increase of dietary guanidylacetic acid(P < 0.05). Conclusion :adding 5 g/kg guanidylacetic acid to the diet of broilers can improve the growth performance,mortality,antioxidant status and intestinal villi morphology of broilers under heat stress.