The ameliorative effect of salts, ascorbic acid olyphosphate and zinc oxide supplementation on heat stress was studied in adult buffaloes of either sex which were randomly divided into two groups of four animals each. Group I served as control and Group II was supplemented with sodium bicarbonate, potassium carbonate, ascorbic acid polyphosphate and zinc oxide. All the animals were exposed to two conditions of temperature and humidity: hot-dry and hot-humid in psychrometric chamber for 4 hours daily for 10 days. Blood was collected on days 1, 5 and 10 of treatment. The activities of enzymes catalase, superoxide dismutase (SOD) and concentrations of reduced glutathione (GSH), hormone cortisol and thiobarbituric acid (TBA) binding substances (lipid peroxidation) were estimated in serum. Significant decreasewas observed in activities of serum catalase and SOD. Serum GSH concentration decreased while serum concentrations of TBA binding substances and cortisol significantly increased in both groups which were subjected to heat stress. Dietary supplementation of ascorbate, zinc and electrolytes resulted in further decrease in the enzymes' activities where as the serum GSH increased at par to normal values. Serum concentrations ofTBA binding substances and cortisol were comparatively lower in supplemented group in both types of stress. Thus, supplementation of ascorbate and zinc in addition to electrolytes relieved the animals of oxidative stress.

Heat stress is major concern for maintaining optimum production in livestock. The improvement of productivity in dairy animals, exposed to adverse environmental conditions, is primarily focused on improving the microclimate and nutritional management of the animals. The experiment was conducted on three groups of animals comprising six adult buffaloes in each group. Two groups were exposed to heat stress in the psychrometric chamber (40oC), the third group was kept under ambient conditions as control. One of the exposed groups was offered ascorbic acid (20g/day/animal). The blood samples were taken at every 4th day up to 16th day. Samples were analyzed for the total plasma protein and plasma albumin. Results showed that as the days of exposure progressed, the level of stress increased which is evident from the elevated level of total proteins. When compared with the ascorbic acid supplemented group (7.28±0.09 gm/dl), the non-supplemented group had higher protein content (7.93±0.13 gm/dl). There was significant difference (P 0.05) in protein levels among the groups. The level of albumin also followed the same pattern as that of total protein but in heat stressed (2.42±0.17gm/ dl) and ascorbic acid supplemented animals (2.41±0.19 gm/dl), the globulin levels declined as compared to group kept at ambient conditions (2.79±0.33 gm/dl). Further, the Albumin:Globulin ratio was significantly (P 0.05) higher in heat stressed animals (2.78±0.43) and ascorbic acid supplemented animals (2.19±0.30) as compared to control group (1.61±0.37). It can be concluded that ascorbic acid supplementation would be beneficial to buffalo producers of the arid/ semi-arid regions in amelioration of stress challenge imposed by the harsh weather.