Effect of summer stress and supplementation of vitamin E and selenium on heat shock protein 70 and anti-oxidant status in Hallikar cattle

Present study was conducted to ascertain the influence of supplementation of vitamin E and selenium on heat shock protein 70 (HSP70) and anti-oxidant status in Hallikar cattle during different seasons. Female Hallikar cattle (12) aged 4 to 6 years selected from Ramanagara, Karnataka, India, were divided into control and supplemented groups with 6 animals in each group. Selected animals were exposed to environmental stressors during 3 different seasons (winter, summer and rainy) by allowing them for free grazing. Animals of supplemented group received oral supplementation of vitamin E and selenium, and control group animals did not receive any supplementation. Blood samples collected from each animal at monthly interval were utilized to determine plasma levels of HSP70 and erythrocyte activities of catalase, superoxide dismutase and glutathione peroxidase in hemolysates (10%). Present study showed significant increase in plasma HSP70 levels during summer compared to winter in control and supplemented groups. However, plasma HSP70 levels did not vary significantly between control and supplemented group during different seasons. Activities of catalase, superoxide dismutase and glutathione peroxidase enzymes were also significantly higher during summer compared to other seasons in both control and supplemented group. However, activities of these enzymes reduced significantly in supplemented group compared to control group animals. From the study, it was concluded that significantly lowered antioxidant enzyme activities in supplemented group indicate beneficial effects of supplementation of vitamin E and selenium during summer.