Effect of Seasonal Stress on Growth Performance, Blood Hemato-biochemical, Antioxidant, Thyroid Hormones and HSP 70 Gene Expression Profile of Beetal Does and Goat Kids

A study was conducted on adult beetal does and growing kids to analyze the effect of seasonal change on various physiological and molecular parameters. Blood samples was collected on 0, 15, 30, and 45th day during summer and winter season. The Average THI was found higher (83.08±0.35) during the summer season, while relative humidity remained high (63.77±2.32) during the winter season. As per ANOVA, values of rectal temperature, respiration rate, heart rate, packed cell volume, hemoglobin, total erythrocyte, and leukocyte count, lymphocyte, eosinophil, total bilirubin, creatinine, blood urea nitrogen, serum ALT, AST, ALP enzyme levels, erythrocytic lipid peroxidation, reduced glutathione, total antioxidant capacity (FRAP value) were found significantly higher, while the values of average daily gain, neutrophil %, glucose, total protein, albumin, globulin, total cholesterol, triglyceride, erythrocytic superoxide dismutase levels were found significantly lower during summer season compared to the winter season. Levels of all tested antioxidants parameters were found significantly lower in goat kids compared to adult does. HSP 70 gene expression levels were found significantly higher, while mitochondrial Cyt-B and COX-I gene expression levels were found significantly lower during the summer season relative to winter season in beetal goats. Overall effect of the summer season on HSP 70, CYTB, and COX-I gene expression relative to winter season was found higher in goat kids compared to adult does. Thus goat kids were found to be more susceptible to heat stress than an adult does. Overall study indicated that adaptability of goats to seasonal stress is governed by altered physiological state of goats in different seasons.