Vol. 10, Special Issue 11 (2021)

Author(s):
J Sai Prasanna

Abstract:
Ever increasing human population is exerting tremendous pressure on natural resources including livestock. Changing global environmental conditions are posing a major threat to the viability and sustainability of livestock production systems in many parts of the World.When climate change occurs, temperatures increase dramatically which impairs the production and reproduction performance, metabolic health status and immune response of different livestock species. Current climate models indicate an increase in temperature by 0.2 °C per decade and predict that the increase in global average surface temperature would be between 1.8 °C to 4.0 °C by 2100. The escalating temperatures have resulted in heat stress becoming an important challenge facing the global dairy industry today. Growing demand for improving milk production and rising temperatures due to global warming has increased the thermal load on dairy animals leading to heat stress. When the heat load of an animal is greater than its capacity to lose heat, a part of the metabolizable energy that is used for production must be diverted to maintain thermal balance. Global warming impairs production and reproduction performance, metabolic health and immune competence of livestock and thus causes decreased milk production and reduced reproductive performance in dairy animal.. In the present review, an attempt has been made to review the impact of heat stress on production and reproduction performance in cattle under the following subheadings.