What dietary supplementation can acclimate broiler chickens to heat stress?

本研究的目的是寻找一种可能的方法来提高慢性热应激肉鸡的生长性能。1)对照组在实验期间线粒体ROS产量变化不大，热应激组（34℃）在热暴露3、5、9 d后线粒体ROS产量均有所增加，14d时恢复到原始水平。2)从0-1日龄雏鸡胸浅肌分离成肌细胞，经41℃培养6 h，细胞ROS产量增加，蛋白含量降低。3)在基础饲粮中添加谷氨酰胺和谷氨酸对热应激肉鸡增重、采食量和十二指肠绒毛高度/隐窝深度的下降有轻微但明显的缓解作用。需要进一步的生化研究，包括肠道功能的改变，以建立缓解应激的方法。

The objective of this study was to find a possible method to improve growth performance of broiler chickens exposed to chronic heat stress. 1)Mitochondrial ROS production for control group showed little changes during the experimental periods, whereas that for the heat-stressed group (34°C)was increased after 3, 5 and 9 d of heat exposure and returned to original levels at 14d. 2)Myoblasts isolated from the pectoralissuperficialis muscles of 0-1 day old chicks were cultured and exposed to 41°C for 6 h, resulting in increased ROS production and reduced protein content of the cells. These changes were attenuated by pretreatment ofan antioxidant, Tempol for 1 h. 3)Supplementation of glutamine and glutamate to basal diets slightly but definitely alleviated decreases in body weight gain, food intake and, and ratio of the duodenal villus height to crypt depth of heat-stressed broiler chickens. Further biochemical studies including modifications of intestinal function are required to establish a method for alleviation of the stress.