How to Protect Cattle from Heat Stress and Improve Milk Production?

Introduction
In India, starting from March till July is known as a summer season, which not only leaves a harmful impact on humans but also on livestock. The increasing temperature causes due to global and environmental warming that leads to the heat stress. Heat stress is one of the biggest challenges faced by Indian dairy farmers in various regions of the world. It can have severe impacts on various functions of the mammal such as health, production and reproduction. It also includes oocyte development, disruptions in spermatogenesis, placental and foetal growth & lactation, early embryonic development, and oocyte maturation. According to the climate, the animal changes its behaviour, particularly feeding, metabolic and physiological functions and the quantity and quality of its production.

Effects of Heat Stress on Milk Production in Cattle
Heat stress has various impacts on the animal’s health. Both reductions in milk production and reproductive functions in buffalo and cattle are major effects of climatic stress. In high environmental temperature, reduced synthesis of hepatic glucose and lower non-esterified fatty acid level in blood cause depression in glucose supply to the mammary glands leading low lactose synthesis that in turn promotes low milk production. Ultimately, it results in a substantial financial loss to the cattle owner through fall in milk production, meat production, animal health, and reproductive efficiency. The heat stress has an indirect effect on non-availability or decrease in water resources and feed. According to latest industry expert’s statement in the 45th Dairy Industry Conference, held by Indian Dairy Association in Mumbai, there might be a loss of over 3 million tons of milk production per year by 2020 because of increasing temperature. The increasing heat and humidity in the air are likely to be directly or indirectly affecting the dairy sector.

How to Protect Cattle from Heat Stress and Improve Milk Production?
The harmful effect of heat stress on livestock should be controlled or minimized by incorporating some effective strategies in terms of food supply and handling management.
• Don’t take cattle to feed, rather take feed to cattle in hot weather. Do not let cattle to walk during hot days
• Protect cows from heat by keeping them under the shade. Improve their comfort level by providing fans or sprinklers before and after milking
• During hot weather, allow cows to pasture for grazing at night. In the night time, cows will do more than 70% of their daily grazing
• Give good quality forages to cows
• Add the energy content in their diet and reduce the intake of metabolic heat load
• Increase the consumption of vitamins and minerals to compensate the decreased feed intake
• Supplementing heat stressed cows with 0.5-0.6% DM sodium and 1.5-1.6% DM of potassium will possibly increase milk yield
• Provide ample amount of cool & clean water. In the hot season, lactating cows can drink 100 L water a day
An arrangement of wetting, fans, well-designed shade can help to lessen the bad impact of heat stress on lactating cows. Feeding strategies, careful management are essential in improving the optimal milk production. Moreover, the collaboration of new technologies into the technology transfer systems and research actually offers great opportunities for the advancement of climate change adaptation strategies.