author(s)
Dr. Alok Khemraj Wankar, Dr. Gyanendra Singh and Dr. Brijesh Yadav

abstract
The study was conducted at Physiology & Climatology Division, IVRI on four dry adult Murrah buffaloes to observe the physio-metabolic alterations and acclimatization process during thermal stress [HS]. The animals were exposed in climatic chambers at 25, 30, 35 and 40 ^oC; 21 days at each treatment. Daily exposure period was fixed from 10.00-15.00 hrs. Rectal temperature [RT], respiration rate [RR], pulse rate [PR] were measured daily in morning and afternoon. Blood was collected on day one and day 21. There was a significant increase in RR, RT & PR at 35 and 40 ^oC, similarly enzymes AST, SOD, serum sodium, potassium also increased during heat stress period (P<0.05). No alteration was observed for other electrolytes, lipid and protein metabolites in the study. The results of the present study indicate that HS severely compromises thermoregulation, alters physio-metabolism and animals require more than 21 days to adapt to short/long term thermal stress.