This experiment aimed to evaluate physiological and behavioral responses of crossbred Dehong dairy buffaloes to heat stress (HS) in comparison with those in a thermoneutral (TN) environment. Twelve crossbred dairy buffaloes at similar lactation stages were randomly allocated to two groups of six animals each. Six buffaloes were exposed to HS conditions and the other six to TN conditions in an open loose-housing barn without individual stalls. Respiration rates were manually recorded at 08:00 h, 13:00 h, and 18:00 h. Duration and frequency of behaviors (standing, lying, feeding, and drinking) were continuously monitored using digital cameras for 20 consecutive days. Compared with the TN group, HS-exposed buffaloes exhibited markedly higher respiration rates (p < 0.001) and feeding frequencies (p < 0.05), but significantly shorter feeding duration throughout the observation period (p < 0.05). No significant differences were observed in the time spent standing, lying, or drinking between the two groups (p ≥ 0.05). Under HS conditions, buffaloes preferred a vertical lying posture to reduce exposure to intense solar radiation. These results suggest that crossbred Dehong dairy buffaloes can adapt to heat stress by modulating their physiological and behavioral strategies. The observed changes in physiological indices and behavioral patterns provide fundamental data for further elucidating the heat stress adaptation mechanisms in dairy buffaloes.
Huang et al. (Mon,) studied this question.