Absorption of immunoglobulin from colostrum in newborn calves

Abstract

SUMMARYOne hundred and forty-one calves, belonging to three different breeds, were each given one single feeding of a variable amount of colostrum from their dams at the age of 2, 6, 10, 14 or 20 hr, respectively.The increase in serum Ig concentration during the first 24 hr after colostrum feeding (Δ Ig % 24) was a function of the mass of Ig fed to the calf, the age at colostrum feeding, and the birth weight of the calf. Among these three factors the mass of Ig and the age of the calf were the two predominant factors. The absorption coefficient, expressing the absorbed fraction of a given amount of Ig, was primarily determined by the age of the calf at first feeding. Thus the absorption coefficient was reduced linearly to about half by delaying the feeding from 2 to 20 hr. Except for a negative effect of increasing amounts of colostrum in one of the breeds, no other factors were detected as responsible for variation in the efficiency of Ig absorption. Thus, the absorption coefficient appeared to be unaffected by the Ig % in the colostrum and also by the quantity of Ig given to the calf.