Adrenal function and passive immunity in the dystocial calf.

Dystocial calves were tested for their ability to absorb colostral immunoglobulins and establish a competent passive immunity. Twenty dystocial and 20 eutocial calves were fed 1 liter of colostrum 4 h after birth and an additional liter 12 h later. Their absorption of the immunoglobulins A, G, and M, as indicated by serum concentrations, was equivalent at 16 and 24 h postpartum. Cortisol concentrations in serum at birth were high in both eutocial and dystocial calves and were correlated negatively with environmental temperatures prior to parturition. The dystocial calves had a lower cortisol concentration in serum at birth. The differences in cortisol concentrations between dystocial and eutocial calves and between experimental blocks influenced by environmental temperature could not be related to immunoglobulin absorption.