| Abstrakt: |
Three experiments were conducted to examine the effects of quality, quantity, and timing of colostrum feeding and the administration of a dried colostrum supplement on serum Ig in Holstein bull calves. In Experiment 1, calves were fed colostrum that had low concentrations of immunoglobulin (Ig; 23.9mg of IgG1/ml) as follows: group 1-1 (n=6), 2L at birth and 2L at 12h; group 1-2 (n=6), 4L at birth and 2L at 12h; and group 1-3 (n=6), 2L at birth, 2L at 6h, and 2L at 12h. Doubling the volume of colostrum administered at birth did not result in higher serum Ig at 48h, but additional colostrum at 6h did increase serum Ig. In Experiment 2, calves received 2L of colostrum that had low concentrations of Ig (25.7mg of IgG1/ml) at birth and 2L at 12h. Calves in group 2-1 (n=6) received colostrum only. Calves in groups 2-2 (n=5) and 2-3 (n=5) were fed additional dried colostrum supplement (136 and 272g, respectively) at each meal. Addition of the supplement reduced efficiency of IgG1absorption and did not result in higher serum Ig at 48h. In Experiment 3, calves were fed as follows: group 3-1 (n=6), 2L of colostrum containing 32.9mg of IgG1/ml (low Ig) at birth and 2L at 12h; group 3-2 (n=6), 2L of colostrum containing 60.1mg of IgG1/ml (high Ig) at birth and 2L at 12h, and group 3-3 (n=5), 4L of colostrum containing 60.1mg of IgG1/ml at birth and 2L at 12h. Colostrum high in Ig resulted in higher serum Ig concentrations at 48h; the concentrations were highest when 4L of colostrum high in Ig were fed to calves at birth. |
