Dairy cattle welfare in terms of heat stress

Heat stress has significant effects on milk production and composition as well as on cattle welfare. Cows with high production capacity have a faster metabolism, produce more heat in the body and more easily tolerate lower temperatures, while high temperatures can easily cause heat stress. Heat stress is state of an organism exposed to external or internal thermal factors whereby the homeopathic systems of the body are unable to resist their harmful effects. Heat stress directly or indirectly affects the physiology, reproduction, health, feeding, production and behaviour of animals and it can cause even death. Negative effects of heat stress on animal welfare can be observed in changes in animal behaviour. Affected animals are also passive, spend less time in social interactions and less time eating. These factors will certainly lead to drop in production. Therefore, it is necessary to study the welfare of the animal through the mental state of the animal, such as frustration or absence of pain, not just through physiological measures. The aim of this study was to review the connection between the heat stress environment and dairy cows’ welfare.