Vol. 9, Issue 5, Part E (2024)

Heat stress in livestock is the global challenge affecting their overall production and productivity. Cattle initiate various adaptive mechanisms to maintain thermal homeostasis. Increased oxidative stress in cattle disrupts the redox homeostasis making them more vulnerable to cellular damage. The Total Antioxidant Capacity (TAC) represents the ability of animal’s endogenous antioxidant defense mechanism to neutralise the reactive oxygen species produced during heat stress. The present study was conducted with the objective of comparing the TAC of crossbred calves under thermo-neutral zone (TNZ) and acute heat stress conditions in a climate-controlled chamber. The TAC values were measured as ferric reducing ability of plasma (FRAP) by the method of Benzie and Strain (1996). The results of the study showed that FRAP values were significantly increased on different days of heat exposure when compared to TNZ. The present finding concluded that TAC of crossbred (Holstein Friesian × Sahiwal) calves increased during acute heat stress to prevent from cellular damage due to oxidative stress and the values remained constant throughout the thermo-neutral condition, indicating the absence of oxidative stress under TNZ.