Norway rat young respond to the energetic demands of their thermal environment with metabolic compensations

Adult rats use metabolic compensations to reduce energetic costs of thermoregulation in their thermal environment. To determine if their altricial young can display these compensations, rats were housed (postnatal days 0-85) in 25 and 33 °C environments. Metabolizable energy intake was recorded weekly and oxygen consumption responses to acute 17, 25, and 33 °C air exposure were recorded every 3 weeks. Thirty-three°C-housed rats consumed less metabolizable energy, gained less body mass, and showed lower oxygen consumption levels in response to 25 °C air compared to 25 °C-housed rats. These results indicate young rats display metabolic compensations in response to their thermal environment.