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...
Three sets of blood samples were taken from 532 beef calves of two populations at 24 to 48 h after birth, at an average age of 164 d (at time of vaccination for infectious bovine rhinotracheitis virus or IBRV) and at an average age of 224 d (60 d postvaccination)....