Short communication: Effect of pH on absorption of immunoglobulin G inneonatal calves

摘要

We fed newborn calves (n = 60) maternal colostrum (n = 12) or a colostral supplement product derived from edible bovine serum (n = 48). Sodium citrate was added to supplements to achieve a final pH of 7.5, 7.0, 6.0, and 5.0. Calves were fed colostrum (2 L/feeding) or supplement (454 g reconstituted in 2 L of water) at 1.2 and 12.6 h of age, which provided a total of 156 (colostrum) or 90 (supplement) g of IgG. We sampled jugular blood at 0 and 24 h of age to determine plasma IgG. Mean plasma IgG concentrations at 0 and 24 h of age were 0 and 6.7 g/L and were markedly higher in calves fed maternal colostrum compared with supplements (10.7 vs. 6.5 g/L) and were higher in Jersey vs. Holstein calves (8.5 vs. 6.1 g/L). Estimated apparent efficiency of IgG absorption was unaffected by treatment and averaged 20. These data indicate that pH of colostral supplements between 7.5 and 5.0 do not markedly influence the efficiency of IgG absorption.