Evaluation of environmental heat stress on physical and hormonal parameters in murrah buffalo

Abstract

| Buffaloes have poor heat tolerance capacity compared to other domestic ruminants and are more prone to heat stress due to scarcely distributed sweat glands, dark body color and sparse hair on the body surface. Thermal environment is a major factor that can affect milk production and reproduction in buffalo especially animals of high genetic merit. Therefore present study was undertaken to study the effect of seasonal stress on Murrah buffalo. Thirty healthy non-lactating Murrah buffaloes each around two years of age were selected for the experiment. Rectal temperature, respiration rate, heart rate and various hormones level were measured in different season to know the effect of heat stress in buffalo. Season had no significant effect on rectal temperature, triiodothyronine (T3) and thyroxine (T4) level. However, it had significant effect on respiration rate(P≤0.05), heart rate(P≤0.01) and cortisol level (P≤0.05) in Murrah buffalo. They had lowest level of respiration rate, heart rate and cortisol level in winter season and highest level in summer. This indicates stressful condition of animal in summer.