Effect of Heat Stress on Productive and Reproductive Health of Animals

Dairy cattle are important part of the livestock sector in India. It is well known that the thermal environment has an integral role in maintaining the health and productivity of cattle. Climate is one of the most important factors in animal adaptation to its surrounding environment and variation in climatic variables such as temperature, humidity, air movement, photoperiod, and solar radiation may impose stress on the productive and reproductive performance traits of animals. According to World Health Organization, World Meteorological Organization and the United Nations Environmental Program, global warming would be a greater frequency and greater duration of exposure to hotter temperatures, especially during the summer months. Because of the climate change effects, summer temperatures have been increasing worldwide and this trend will continue in near future also. Among the livestock, dairy animals are likely to be impacted greatly by the effects of climate change. The IPCC (2007) predicts that by 2100 the increase in global average surface temperature may be between 1.8°C to 4.0°C. India also experiencing increased average temperatures and humidity, and more hot spells recently. Heat stress due to high ambient temperature and humidity elicits harmful effect on growth, production and reproduction of farm animals. Typical hyperthermia sometimes occurs during severe heat in summer and as a result of hard expose to sun throughout the world.