Journal of Animal Research

Present study demonstrates the influence of heat stress on adaptability and physiological responses in cross-bred cattle. Eighteen cross bred cows were selected from three districts of central plane zone of Uttar Pradesh, on the basis of their body weight, body condition and parity and were divided into three groups, 6 cows were kept in each district. The experiments were carried out in spring and summer season at Lucknow, Unnao and Sitapur districts of Uttar Pradesh. Physiological responses viz. Rectal Temperature, Pulse rate and Respiration rate are recorded twice a day during both seasons. Temperature Humidity Index (THI) of all three districts was also calculated. There was found a significant (P<0.01) deference in THI values in spring and summer seasons in all three districts. There was no significant change in Physiological response like Rectal Temperature, Pulse Rate and Respiration Rate in both seasons in morning hours but there was found significant (P<0.01) increase in Rectal Temperature, Pulse Rate and Respiration Rate in summer season as compare to spring season at afternoon. Overall Mean ± SEM of Iberia heat Tolerance coefficient and Gaalaa’s heat Tolerance coefficient were significantly (P<0.01) more closure to 100 in spring season as compared to summer season. Overall Mean ± SEM of Benezera coefficient of Adaptability and Dairy Search Index was significantly (P<0.01) more closure to 2.00 and 1.00 respectively in spring season. In conclusion Heat tolerance indices and physiological responses show more adaptability in spring season as compared to summer season in cross-bred cows.