Assessment of thermal environment of cow house in free stall bran system

The experimental dairy cow house with the roof of single-layer color steel plate located in Zhengzhou City,Henan Province, which was built along the north to south direction. The air temperature, THI and wind velocity of the cow house were determined and the rectal temperature, the temperature of the frontal shoulder surface, the temperature of udder surface and respiratory rate of the Holstein cows were measured in one dairy farm in the experiment site. The results showed that when the average temperature and THI outside the cow house in winter were 0.76℃ and 41.98, the average temperature and THI were﹣0.52℃ and 39.34 inside the cow house and 1.63℃ and 39.99 in the resting cubicle, the average rectal temperature, the temperature of the frontal shoulder surface and the temperature of udder surface of cows were 38.72, 29.33 and 35.27℃,respectively, in winter. When the average temperature and THI outside the cow house in summer were 24.25℃ and 73.54, the average temperature and THI were 25.69℃ and 74.98 inside the cow house, the rectal temperature and the respiratory rate of cows were 39.42℃ and 59.56times／min in summer. It was reminded that there is an inferior capability of heat insulation of cow house with the roof of single-layer color steel plate and along the north to south direction, and the thermal environment of it in summer and winter was not very suitable for dairy cows in the central plain of China.