Assessment of housing environment and its impact on dairy behavior and milk production in Northeastern China

Abstract. Northeastern China is a dominating area of dairy milk production and characterized by a warm summer and an extremely cold winter. The aim of this study was to assess the thermal environment of the dairy barn in summer and winter, using the indices of THI (Temperature Humidity Index), BGHI (Black Globe-Humidity Index) and CCI (Comprehensive Climate Index) based on the continuous measurement of thermal environmental factors, as well as core body temperature (CBT), behavior and milk yield information of dairy cows. Results showed that cows went through mild to moderate heat stress in summer (40.9% and 17.9% of the total hours during the measurement, respectively) and no to mild cold stress in winter (87.5% and 12.3% of the total hours during the measurement, respectively). Under heat stress, CBT of the cows increased from 38.8oC to 39.3oC (P