Changes in Serum Electrolytes, Minerals and Physiological Responses in Buffalo heifers Exposed to High Temperature in a Psychrometric Chamber

Twelve buffalo heifers weighing 270–280 kg were used in this study. Six heifers (Group 1) were kept in the animal shed in the months of November and December and served as control. The minimum temperature in the shed was 7–8°C and maximum temperature 17–18°C and RH 70–80%. Six animals (Group 2) were exposed in the psychrometric chamber at 40°C for 4 hours daily for a period of 16 days. Physiological responses RR, PR and RT were comparable in both groups before exposure to high temperature. After 4 hours of exposure, the physiological responses increased significantly (p<0.05) in group 2 compared to beginning of the exposure throughout the exposure period. The overall average values of RR, PR and RT were statistically non-significant between groups. But the values were significantly higher in group 2 compared to group 1 after 4 hours of exposure. There was no significant change in Na, K and Cl concentration of group 1 at 0, 8 and 16 day of exposure. In group 2, the concentration of electrolytes decreased significantly at day 8 and 16 of exposure. The overall values of Na, K and Cl were significantly lower in group 2 compared to group 1. There was no significant difference in Ca concentration in group 1 and group 2. The concentration of P and Mg of group 2 were significantly lower compared to group 1. The study indicated shift in electrolytes, minerals and physiological changes under heat stress and the data may serve as base for adopting ameliorative measures to combat heat stress in buffaloes.