Influence of heat resistance on reproduction and productivity of Red Dairy Breed cows

Abstract

In this article we discuss the indicators of heat resistance of cattle. The studies were carried out on the livestock of the red dairy breed: group I – the intrabreed fatty-milk type obtained by crossing the red steppe breed with the Angler, group II - animals obtained by crossing the red steppe breed with the red-mottled Holstein. It was found that with temperature comfort, the difference in temperature and pulse rate between the animals of the fatty-dairy and holstenized types was insignificant, but with the increase of the air temperature to 39 C, these indicators were increased. The respiratory rate was significantly lower in the first heifers of the fatty-milk type both at elevated temperature load and in physiologically comfortable environmental conditions. Animals of both intrabreed types resisted the specific agro-climatic conditions of Donbas quite well. In terms of adaptive abilities to the high summer temperatures of Donbas, holstenized intrabreed type animals are noticeably inferior to fat-milk intrabreed type cows.