Heat stress in dairy cows

Abstract

This review includes an analysis of the literature on various influencing factors influencing heat stress in lactating dairy cows and the way it affects milk production. Signs and symptoms of heat stress in cows are reduced feed consumption and decreased milk yield, elevated breathing rate, increased body temperature and reduced reproductive overall performance. There are other problems for example, a seasonal growth in bulk tank somatic cell counts. The birth weight is decreased in cows which have been exposed to heat stress throughout the dry length. It is established that the most critical is the heat accumulated via direct radiation from the solar. It was found out that high feed consumption results in raised metabolic heat increment. High metabolic warmness increment requires powerful thermoregulatory mechanisms to maintain body temperature in a thermoneutral area and in physiological homeostasis. It is confirmed that heat stress is complicated because the responses to heat stress have an effect on not best the energy stability, but also water, sodium, potassium and chlorine metabolism. Plasma progesterone degrees may be elevated or reduced depending on whether or not the heat pressure is acute or chronic. Water, sodium, potassium and chlorine are vital constituents of sweat, and sweating is a chief, if not the most important, thermoregulatory mechanism used to burn up extra body heat. Strategies to reduce heat stress must be evolved to enable cows to express their full genetic ability. Key words: dairy cows, heat stress, thermoregulatory mechanism, water, feed consumption, mineral elements.