A Review on Thermoregulatory Responses in Tharparkar Cattle against Heat Stress

In changing climatic scenario, heat stress has become one of the most important challenges faced by dairy industry today. To maintain appropriate microclimate in animal houses i.e., sufficient air circulation, temperature, humidity, low pollution and low content of gases have been major factor to concern. These factors significantly contribute to the proper development and maintenance of cattle welfare and subsequently livestock-based food security. India ranked fifth in the Global Climate Risk Index, 2019 and extreme heat has potentially deadly effects of climate change, especially for populations living in the tropics. Dairy cattle show heat stress when the temperature humidity index (THI) is higher than 72 (Armstrong, 1994). Their threshold for heat tolerance depends on the genotype as well as production level. Animals on higher production levels tend to be more sensitive to heat stress. Indigenous evolved crossbred cattle like Karan Fries, had higher metabolic heat production, methane, energy loss and physiological responses as compared to zebu cattle. The lower metabolic rate of zebu breeds indicates better adaptability of it to tropical climatic condition in terms of heat and methane production. Among, Indigenous cattle breeds Tharparkar exhibits more tolerance to heat stress then breeds like Sahiwal, Gir, Red Sindhi and crossbreds. Thermoregulatory responses play major role in conferring thermotolerance against heat stress through expression of highly conserved family of proteins known as heat shock proteins (HSPs). Despite these thermoregulatory responses toward heat stress prodigiously muddles Zebu cattle Tharparkar’s productivity as compared to other indigenous and crossbred cattle.

• Study of thermoregulatory responses to identify climate resilient animals for food security.

• Documenting responses of Tharparkar cattle as adaptive response against heat stress.