Impact of heat stress on tropical livestock and various approaches for mitigation

Abstract

Stress, often viewed negatively, encompasses various factors that can adversely affect the health and performance of animals. Heat stress arises when there's an imbalance between the body's heat production and its dissipation, contributing to oxidative stress. Reactive oxygen species (ROS), generated as a natural byproduct of metabolism, can lead to oxidative stress if their levels exceed a certain threshold. This can result in the gradual degradation of polyunsaturated fatty acids (PUFA), ultimately damaging cell membranes. The body employs antioxidants to counteract these free radicals. Enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) scavenge intracellular and extracellular superoxide radicals, preventing lipid peroxidation of cell membranes. Non-enzymatic antioxidants, including vitamins C, A, and E, as well as proteins like albumin and glutathione (GSH), also play a crucial role. Supplementation with antioxidant nutrients, particularly vitamins C, A, and E, zinc, and chromium, can mitigate the adverse effects of environmental stressors.