Effect of Melatonin on Blood Electrolytes, Biochemical Profiles and SOD Activity of Beetal and Assam Hill Goat Exposed to Direct Sunshine during Summer in Assam

Abstract

The present study was carried out to evaluate the heat-stress ameliorating effect of melatonin. A total of 18 animals (5-6 months old) of each healthy Beetal and Assam Hill Goat (AHG) was divided into three groups containing 6 animals in each. One group was kept indoor (T-1), while other two groups (T-2 and T-3) of each breed were exposed to direct sunshine @6 hours/day for 30 days. Melatonin was fed @6 mg/animal to one of the two exposed groups (T-3). Blood samples were collected at weekly interval before and after exposure. Blood Na⁺ and K⁺ decreased significantly (P<0.01) in all the exposed groups and their level were significantly lower (P<0.01) in T-2 group than in T-3 group. The Na⁺ and K⁺ level were significantly higher in all the groups of AHG than Beetal goats. The superoxide dismutase activity decreased in all the exposed groups, but the decrease was only significant (P<0.01) in the T-2 group. The SOD activity were significantly (P<0.01) higher in AHG than the Beetal. Serum total protein and albumin decreased significantly (P<0.01), but their level was significantly (P<0.01) higher in T-3 group of Beetal goat. In AHG, total protein was significantly higher in T-3 group, but no significant (P>0.05) difference was observed for albumin. The blood glucose decreased insignificantly after the exposure in both the breeds, but it was significantly (P<0.01) higher in the T-3 group of both the breeds. Melatonin plays a positive role in the different blood electrolytes, blood biochemicals and anti-oxidative enzyme activity in AHG and Beetal along with stress ameliorating effects and AHG are more adapted to heat stress due to solar radiation under agro-climatic conditions of Assam.