Adaptative thermal traits in farm animals

Animal welfare is affected by weather conditions that influence on thermal comfort, therefore the aim of this literature review was to assess the influence of environmental factors on physiological variables of animals of zootechnical interest. Livestock production is limited by the animal stress as response to the environment where the individuals are reared. Animal adaptation is related to the individual physiological condition related to its survival zone, which is determined by thermoneutral zone (comfort), hypothermic zone (cold stress) and hyperthermia (heat stress). To assess the animal comfort some variables must be analysed, such as: respiratory rate (RR); sweat rate (SR); rectal temperature (RT); heart rate (HR); air temperature (AT); air humidity (AH); wet-bulb globe temperature index (WBGTI) and radiant thermal charge (RTC). The weather variables influence the animals’ thermoregulation, affect their thermal comfort and decrease their welfare. The adaptation to the weather conditions of the region is one of the factors responsible for the productive capacity of the animal.