Effects of heat stress on the welfare of extensively managed domestic ruminants (2000)

Silanikove, N.

Abstract

High ambient temperatures, high direct and indirect solar radiation, and humidity are environmental stressing factors that impose strain on animals. This review concerns the heat stress-strain response of domestic ruminants from the viewpoint of animal welfare. Despite having well developed mechanisms of thermoregulation, ruminants do not maintain strict homeothermy under heat stress. There is unequivocal evidence that hyperthermia is deleterious to any form of productivity, regardless of breed, and stage of adaptation. ... Physiological (sweating, panting), hormonal (cortisol, thyroid gland activity), and behavioral thermoregulatory responses are discussed in respect to animal welfare. .. Some practical measures that are applicable under extensive conditions, such as provision of shade shelter, are suggested.