One of the most important losses in animal husbandry is yield loss of neonatal calves. The first hour of birth and life in newborn neonatal is very important for the survival of life. According to the results of the research, it is reported that the mortality rates of the calves are higher in the beginning of spring and in the winter season. Approximately 50 to 53% of calf defects in the neonatal period occur at birth or within two days of life. The most important cause of calf’s losses is the formation of hypothermia in newborns because of the temperature of the environment is much lower than body temperature of calf, the change of air temperature (cold air and strong wind), the calf wetness and the lack of thermoregulation. In this review, detailed information about causes of hypothermia, treatment and prevention of neonatal calf defects will be provided.

Keywords: Calf, Newborn, Hypothermia