夏季湿热因素对奶牛行为和生理指标的影响

摘要

以健康荷斯坦奶牛为试验对象,研究了温度和湿度因素对奶牛生理和生产性能的影响.结果表明:随着温湿度数(THI)的升高,奶牛的采食时间和伏卧时间占总观察时间的比例降低；反刍持续时间延长和每次反刍咀嚼次数增加；奶牛夏季的呼吸频率、直肠温度与THI呈高度的正相关(r=0.964),随着THI的升高,奶牛的呼吸频率和直肠温度升高.热应激能够显著影响奶牛的直肠温度和呼吸频率,且对高产奶牛的负面影响程度大于中低产奶牛.%The experiment mainly studied the influence of THI (temperature and humidity index)on physiology index of dairy cattle in summer.The results showed that with the increase of THI,the grazing time and rest time reduced,and the water-drinking time and the chewing frequency increased.The positive correlation was found between the anal temperatures and breathing rate (r=0.964).And with THI increasing,breathing rate and rectum temperature also increased.It was concluded that heat stress could raise the rectum temperature and breathe rate of dairy cattle.And the negative effect was severe for the high-yielding cows compared with the mid and low-yielding cows.