Evaluation of some serum hormones and biochemical parameters of buffalo in hot and cold seasons in Ahvaz

Among the environmental factors، “heat stress” is the most important one that can cause a decrease in the reproduction of the herd in dry and hot regions. It can be a challenge for animals to keep energy balance، hormonal and mineral changes. Lack of balance between electrolytes and mineral substances during the heat stress leads to decrease the performance and fertility in animals. Most of these physiologic responses of animals to heat stress are aid strategies used by animals to keep their body temperature. To do this study، initially 200 blood samples were taken from buffalos after they were slaughtered in two seasons of summer and winter. Then، the serum was separated and the serum concentration of glucose، urea، cholesterol، creatinine، albumen، total protein and triglyceride، calcium، phosphorus، sodium، potassium and CK، AST، ALT، LDH، ALP and hormones such as T3، T4 and cortisol were assayed. In this study، there was a significant difference in the serum concentration of glucose، cholesterol، total protein، calcium، phosphorus، sodium، CK، AST، ALT، LDH، ALP، T3، T4 and cortisol between hot and cold seasons of the year (p<0. 05). In the winter، the levels of glucose، cholesterol، total protein، calcium، phosphorus، CK، ALT، LDH، ALP، T3، T4 in serum were higher (p<0. 05). On the other hand، the Concentration of blood sodium، cortisol، AST werer higher in summer rather than winter (p<0. 05) and the rate of urea، creatinine، albumen، triglyceride، potassium had no significant difference. The results of this study show that the environmental heat can have destructive and harmful effects on body elements. Those effects may lead to decreasing in growth، fertility and production.