Effect of heat stress, determination of temperature-humidity index

Relevance . Increased values of temperature and relative humidity of the external environment lead to negative consequences for the animal body, forcing the thermoregulation processes to be turned on. These mechanisms allow the animal organism to adapt to new environmental conditions at the expense of productivity. In these cases heat stress is observed. It is established that its manifestation is observed after 17 hours and there is a possible decrease in productivity by 35–40%. To identify the effect of heat stress, accurate determination of temperature-humidity index (THI) is necessary. Methods . The materials and methods contain the most common formulas for determining the temperature and humidity index. The equipment and software package used for the research are presented. Results . A graph of the results of South Korean studies is presented to compare the effects of heat stress on productivity. The results and discussions display a modernized formula for determining the heat stress index and figures showing the level of heat stress at different temperature and relative humidity levels.