Observations on neonatal changes of body temperature in Blackface lambs

Abstract

Studies of rectal temperature changes in Blackface lambs from birth to 24 hr indicated a very limited effect within an ambient temperature range of 28 to 66°F. The rectal temperature of twins at birth was lower than that of singles, but the difference disappeared by 3 hr after birth. Body weight was correlated with rectal temperature at birth only in twins. In both twins and singles there was an elevated level of rectal temperature after birth which was presumably associated with a postnatal rise in metabolic rate similar to that which occurs in other species. It is concluded from the results that heat regulation is completely developed within a short interval of birth.Changes in body weight at intervals up to 48 hr were small, and body weight was significantly different from that at birth only at 48 hr in single lambs.