The effect of low environmental temperature on plasma corticosteroid and glucose concentrations in the newborn calf.

Abstract

SUMMARY Exposure of newborn Holstein and Jersey calves to −4 °C did not significantly increase the plasma corticosteroids (cortisol and corticosterone) concentrations compared with calves kept at 16 °C. Two Holstein calves exposed to −12 °C showed a slight decrease of plasma corticosteroid concentrations and one Holstein calf at −18° C responded with a marked increase in both hormones during cold exposure. In the animals at 16 and −4 °C the plasma cortisol and corticosterone concentrations fell steadily during the sampling period. There was also a marked, and almost linear, decrease in the packed cell volume during the sampling period; this occurred in all groups. That this was not due entirely to the withdrawal of blood was shown by a similar decrease in two calves from which only small quantities of blood had been taken. Thus, the decrease in plasma corticosteroids may have resulted to some extent from haemodilution. An increase in glucose concentration was observed in both the control and cold-exposed calves. There was no correlation between the changes in plasma glucose and plasma corticosteroids.