Physiological responses of Munjal sheep to variations in temperature humidity index in subtropical climate

Understanding the relationship between physiological parameters of livestock and temperature humidity index (THI) is essential for developing effective management strategies aimed at mitigating heat stress, especially during periods of elevated temperatures. The present study examined the physiological parameters of rectal temperature (RT), respiration rate (RR), and pulse rate (PR) in Munjal sheep reared in a subtropical climate, focusing on their association with THI. Data were collected from 29 female Munjal sheep at 15-day intervals, during morning (8:00 a.m.-10:00 a.m.) and afternoon (2:00 p.m.-4:00 p.m.) over one year. Results showed that RT was significantly higher in the afternoon compared to the morning for both lambs and adults. Likewise, RR and PR were elevated in the afternoon across both groups. In young lambs, RT (r = 0.86) and RR (r = 0.71), and in adults, RR (r = 0.89) and PR (r = 0.91) demonstrated a significant positive correlation (P < 0.05) with THI. These findings indicate that higher physiological parameters during hotter periods necessitate additional care for young lambs. In conclusions, this study highlighted the critical need for targeted management practices to support the physiological well-being of Munjal sheep in subtropical climates, particularly during periods of high temperature humidity index, ensuring optimal health and productivity.