COLD THERMOREGULATION IN THE NEWBORN CALF

During the fetal to neonatal transition, the newborn calf encounters s evere thermolysis due to an abrupt change in thermal environment that is compounded by evaporation of fetal fluids and severe weather condit ions. Maintenance of homeothermy during the neonatal period necessitat es an acute and sustained thermogenic response by the newborn calf. It is now widely accepted that this thermogenic response is derived from both shivering thermogenesis in muscle tissue and nonshivering therom genesis in brown adipose tissue (BAT). It is critical that newborn cal ves possess functional BAT during the neonatal period. This article fo cuses on the pre- and postnatal factors that influence nonshivering th ermogenesis of BAT in the neonatal calf.