Vol. 11, Special Issue 12 (2022)

The climate is changing and temperature is increasing day by day due to global warming. Dairy animals are homeothermic in nature so they maintain their body temperature when temperature exceeds. Within thermo-neutral zone there is no need to regulate the body temperature by physiological and behavioural changes by animals but if environmental parameters (temperature and humidity) exceed certain point then dairy animals cannot maintain their welfare in normal conditions, also there is imbalance between metabolic heat production and heat dissipation to the surrounding results in heat stress. Heat exchange between animal’s body and surrounding is carried out in sensible and evaporative way and the sensible heat loss via conduction, convection, radiation and evaporative heat loss through respiration and sweating loss. Heat stress has various negative impacts on dairy animals like feed intake, production and reproduction. There is various heat stress indices used to measure the effect of heat stress on animals. Each index has potential to measure the heat stress according to climatic conditions. The different kinds of heat stress reducing techniques are in practice which is used according to climates and structural design of dairy barn.