Addition of Casein or Whey Protein to Colostrum or a Colostrum Supplement Product on Absorption of IgG in Neonatal Calves

Davenport, D. F.; Quigley, J. D.; Martin, J. E.; Holt, J. A.; Arthington, J. D.

Abstract The effects of the addition of nonimmunoglobulin protein on absorption of immunoglobulin G (IgG) from colostrum or colostrum supplement products were determined in two experiments. In experiment 1, 48 Holstein calves were fed 4L of pooled maternal colostrum or 4L of reconstituted colostrum supplement with 0, 200, or 400g of added whey protein concentrate or casein. In experiment 2, 38 Jersey calves were fed 2L of pooled maternal colostrum with 100 or 200g of whey protein concentrate or casein added immediately before feeding. Blood was collected at 24h of age and plasma IgG concentration, total protein, hematocrit (experiment 1 only), and plasma urea N were determined. In experiment 1, blood samples were also collected at 4, 8, 12, 16, and 20h to evaluate absorption of IgG and protein and urea N concentrations. The addition of 400g of casein to colostrum supplement in experiment 1 reduced plasma IgG from 5.66g/L (0g of casein addition) to 3.88g/L, increased plasma urea N at 24h, and reduced the change in plasma total protein from 0 to 24h. Hourly plasma IgG concentrations increased with the consumption of colostrum or supplements but increased more rapidly in calves fed whey protein concentrate and more slowly in calves fed casein. The addition of 200g of casein or whey protein concentrate to colostrum supplements had no effect on plasma IgG concentration at 24h of age. The addition of 100 or 200g of casein or whey protein concentrate to maternal colostrum had no effect on plasma urea N, total protein, or plasma IgG in experiment 2. The addition of nonimmunoglobulin protein to colostrum supplements or maternal colostrum did not affect IgG absorption from the intestine of newborn calves unless the amount of total protein exceeded 500g of protein.