Hypothalamic neuromodulation and control of the dermal surface temperature of livestock during hyperthermia

Abstract

Hyperthermia elicits several physiological and behavioral responses in livestock to restorethermal neutrality. Among these responses, vasodilation and sweating help to reduce core bodytemperature by increasing heat dissipation by radiation and evaporation. Thermoregulatory behaviorssuch as increasing standing time, reducing feed intake, shade-seeking, and limiting locomotoractivity also increase heat loss. These mechanisms are elicited by the connection between peripheralthermoreceptors and cerebral centers, such as the preoptic area of the hypothalamus. Considering theimportance of this thermoregulatory pathway, this review aims to discuss the hypothalamic controlof hyperthermia in livestock, including the main physiological and behavioral changes that animalsadopt to maintain their thermal stability.