Plasma Cortisol Concentrations in Newborn Calves

Abstract

SUMMARY Plasma cortisol concentration in the newborn calf (12.1 ± 1.1 μ g./100 ml.) was greater than that in the dam (5.0 ± 1.2 μ g./100 ml.). Cortisol concentrations in the calves decreased to 4.9 ± 1.1 μ g./100 ml. at 12 hours, then more slowly to 1.1 ± 0.3 μ g./100 ml. on the 12th day. Calves had leukocytosis, eosinopenia, and a preponderance of neutrophils to lymphocytes at birth. The leukocyte pattern became more normal as plasma cortisol decreased.