热应激对肉牛生产的影响

Effects of heat stress on beef cattle production

动物健康与生产潜力受多种因素影响,热应激是其中主要的影响因素之一。尽管热应激对肉牛生产的影响没有像奶牛一样明显而直接,但这种影响也不容忽视。本文首先介绍了影响肉牛养殖的环境因素,其次详细阐述了温湿度指数(THI)的概念及三种主要的评定方法,最后对热应激影响肉牛体温、采食量、血清激素水平、繁殖能力、免疫功能等方面进行综述。综上所述,作者建议采用物理降温、营养调控和遗传选择等措施提高肉牛对热应激的适应能力。

Heat stress is one of the main factors that affect animal health and animal production potential.Although the effect of heat stress on beef cattle is not as obvious and immediate as that on dairy cattle,it is still worth our attention.Here,we first briefly introduce the effects of environmental factors on beef cattle breeding,and then elaborate in detail the concept of thermal-humidity index (THI)and three methods for assessing THI.Finally,we expound the effects of heat stress on body temperature,feeds intake,hormone level in serum,reproductive capacity and immune system function of beef cattle.Based on the above information,we suggest that different measures of physical cooling, nutrition regulation and genetic selection should be taken to enhance the adaptive capacity of beef cattle to heat stress.