Temperature regulation and fertility in male and female mammals.

Abstract

Thermal effects on endocrine mechanisms where they seem to provide direct evidence for interference with gonadal function are discussed. Heat appears to be the major threat to reproduction in both male and female mammals. Cold unless very severe interferes with reporductive potential only during the early postnatal period. Fertility in the male is more vulnerable to high ambient temperatures. The action of heat is directly on the testes. The longer the period of heat stress the greater the period of semen damage. Recovery is rapid. Effective thermoregulation by both parents during heat stress is necessary to ensure successful implantation of a viable embyro. In many species apart from its improtance as a local thermoregulator the scrotum is a source of sensory information about the thermal environment. In sheep thermal inputs from the scrotum may alter deep body temperature.