Inheritance of Maternal Immunoglobulin G1 Concentration by the Bovine Neonate

Abstract

Serum samples were collected between 24 and 48 h of age from 408 Hereford calves of a Selection Experiment and from 200 Angus, Hereford and Red Poll calves of another experimental population (Germ Plasm Utilization Project). Concentrations of immunoglobulin G₁ (IgG₁) were determined by single radial immunodiffusion. Breed or selection line of calf and age of dam were the most important factors influencing IgG₁ concentrations (P< .01). In the Germ Plasm Utilization (GPU) herd, Angus calves were highest, Red Polls were intermediate and Herefords were lowest in serum concentrations. Calves from Hereford lines selected for weaning weight, yearling weight or an index based on yearling weight and muscling score were lower in IgG₁ concentration than calves from the randomly selected control line. In both populations immunoglobulin levels in the calf increased as age of dam increased. In Selection Experiment Herefords, increased calving difficulty was associated with a decrease in calf IgG₁ levels (P<.05). Heritabilities of calf serum IgG₁ concentration, estimated from paternal half-sib analysis on a within line or breed basis, were .03 ± .09 and .13 ± .19 in the two populations. In the Selection Experiment Herefords, when the component of variance for selection line was added both to the numerator and denominator of heritability, the revised estimate was .09 ± .09. Heritabilities of maternal effects on IgG₁ concentration were also estimated (by nesting calves within maternal grandsires) on a within line or breed basis. These heritabilities were .23 ± .17 and −.07 ± .27 for the Selection Experiment and GPU populations, respectively. In the Selection Experiment population, when the variance component for selection line was added to the numerator and denominator of maternal effects heritability, the estimate was .27 ± .17. Those calves that died had a lower mean IgG₁ concentration than the population average (P<.01). Copyright © 1984. American Society of Animal Science . Copyright 1984 by American Society of Animal Science.