Effect of heat stress mitigations on physiological, behavioural, and hormonal responses of Buffalo calves

Abstract

This study assessed the effect of heat stress mitigations on the physiological, behavioural, and hormonal responses of buffalo during the hot summer season. Twenty Murrah buffalo male calves were distributed randomly into controlled (C, n = 10) and treatment groups (T, n = 10). The buffalo calves in the C group were housed in the existing shed (10-12-ft height and 10-ft width). Buffalo calves of the T group were allocated in the modified shed: 15-ft height and 20-ft width along with time-controlled pressure mist with fans and rubber mats on the floor. Fans were running all days. The cool water was misted on calves at the rate of 1 min in 5 min, from 11:00 to 18:00 h. The water misting system was installed below the roof, but at 3.5 m above the floor. The calves' body weight, rectal temperature, infrared temperature of the eye, blood samples, respiration rate, and pulse rate were recorded fortnightly for two consecutive months. In one-way ANOVA, rectal temperature, eye temperature, cortisol level, and afternoon's respiration and pulse rate were higher in the calves of C group than that of T group (P < 0.05). Conversely, eating and resting time (min/day) and triiodothyronine were lower in the calves of C group than that of T group (P < 0.05). Therefore, an increase in shed's height and width, using rubber mats on the floor, and cool water misting to buffaloes during the hot summer seasons positively influence their physiological, hormonal, and behavioural responses.

Keywords: Cortisol; Heat stress; Infrared temperature; Rectal temperature.