Review: the influence of genotypic and phenotypic factors on the comfort and welfare rates of cows during the period of global climate changes

The study of the influence of weather phenomena on behavioural and physiological processes plays an important role in the development of highly effective methods of dairy farming management. Climate and weather factors have important signification in the system of interaction "organism-environment". One of the main factors of cows’ comfort improvement in different types of premises, on ground runs and pastures is the creation of such indicators of microclimate that would best meet the biological needs of dairy cows, depending on the season and productivity. Due to the constant metabolic processes, the body of cattle is very hurtable to ambient temperature. This is especially felt during periods of prolonged low or high-temperature shocks. Disorders of metabolic and thermoregulatory processes directly affect the duration and nature of behavioural and physiological reactions and cause stress in animals. Prolonged temperature stress is the reason for fluctuations in productivity, quality of milk and problems with reproduction and together significantly affect the profitability of production. To reduce the impact of temperature stress on the body of dairy cows, scientists have proposed management strategies during periods of high and low-temperature shock. These strategies are divided into genotypic: the selection of heat-resistant individuals of different breeds and phenotypic: the use of microclimate control methods and modernization of feeding management methods. The effect of temperature stress on the body of dairy cows can be minimized due to genotypic (breeding of heat-resistant breeds) and phenotypic factors (water irrigation systems, ventilation, and the use of shade shaded shelters in summer and insulation of side curtains in winter), or a combination thereof. The purpose of this article is to summarize existing knowledge about the effects of temperature stress on the health, productivity and comfort rates of cows and to discuss management strategies that would mitigate the effects of these factors.