Biochemical changes in heat exposed buffalo heifers supplemented with yeast.

Serum electrolytes, minerals, blood biochemical and plasma enzymes were studied in heat exposed buffalo heifers supplemented with yeast powder in feed to alleviate the adverse effects of heat stress. Eighteen healthy Murrah buffalo heifers (270-280) kg were divided into three groups. Animals of group I were kept in shed and served as control, while group II and group III were exposed in a psychrometric chamber at 40°C for 4 hrs daily for 16 days continuously. The animals in group III were also supplemented with yeast powder at 10 g per animal per day. The serum sodium, potassium and chloride levels decreased significantly (P < 0.05) in group II and their levels tended to be maintained in group III. Serum calcium, magnesium, phosphorus, glucose and total cholesterol concentration decreased (P < 0.05) significantly whereas total protein increased in group II due to heat stress. The levels of these minerals tended to be normal in group III. The plasma concentration of SGOT and SGPT increased significantly (P < 0.05), whereas the concentration of plasma alkaline phosphatase and acid phosphatase decreased due to thermal exposure. The levels of these enzymes tended to be normal in group III. The results indicated significant deviations in blood biochemical due to thermal stress and their levels tended to be normal in yeast supplemented group of buffalo heifers.