热应激对肉鸡的生理危害与缓解措施

Physiological hazards of heat stress to broilers and its mitigation measures

环境温度超过动物机体等热区中的舒适温度上限后会产生热应激现象。肉鸡体毛丰厚、生长速度较快、无汗腺,受饲养密度的影响,在高温环境下易出现热应激现象。热应激容易造成肉鸡采食量减少、生长速度减缓,降低肉鸡免疫防御功能,抑制免疫器官的生长发育,增加组织炎性细胞因子表达。热应激能够降低肠道绒毛高度,增加隐窝深度,使肠道结构受损,肠道微生物菌群的数量发生改变。热应激轻则导致肉鸡生理功能紊乱,严重时会导致肉鸡死亡,造成经济损失。文章总结了热应激对肉鸡生产性能、免疫性能、肠道形态和肠道屏障方面的影响以及预防和缓解热应激的措施,为生产实践中预防和缓解热应激提供参考。

Heat stress occurs when the ambient temperature exceeds the upper limit of the comfortable temperature in the thermal area of the animal body.Broilers have thick body hair,fast growth rate,and no sweat glands.Due to the influence of feeding density,they are prone to heat stress in high-temperature environments.Heat stress can lead to a decrease in feed intake and slower growth rates in broilers.It also reduces their immune defense functions,inhibits the growth and development of immune organs,and increases the expression of inflammatory cytokines in tissues.Heat stress can lower the height of intestinal villi and increase the depth of crypts,causing damage to the intestinal structure and altering the quantity of the gut microbiota.Mild heat stress can lead to physiological dysfunction in broilers,while severe heat stress can lead to death,resulting in economic losses.This article summarizes the effects of heat stress on the productive performance,immune performance,intestinal morphology,and intestinal barrier of broilers,as well as preventive and mitigative measures against heat stress.It provides a reference for the prevention and mitigation of heat stress in practical production.