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; 23.9 mg of IgG1/ml) as follows: group 1-1 (n = 6), 2 L at birth and 2 L at 12 h; group 1-2 (n = 6), 4 L at birth and 2 L at 12 h; and group 1-3 (n = 6), 2 L at birth, 2 L at 6 h, and 2 L at 12 h. Doubling the volume of colostrum administered at birth did not result in higher serum Ig at 48 h, but additional colostrum at 6 h did increase serum Ig. In Experiment 2, calves received 2 L of colostrum that had low concentrations of Ig (25.7 mg of IgG1/ml) at birth and 2 L at 12 h. 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 272 g, respectively) at each meal. Addition of the supplement reduced efficiency of IgG1 absorption and did not result in higher serum Ig at 48 h. In Experiment 3, calves were fed as follows: group 3-1 (n = 6), 2 L of colostrum containing 32.9 mg of IgG1/ml (low Ig) at birth and 2 L at 12 h; group 3-2 (n = 6), 2 L of colostrum containing 60.1 mg of IgG1/ml (high Ig) at birth and 2 L at 12 h, and group 3-3 (n = 5), 4 L of colostrum containing 60.1 mg of IgG1/ml at birth and 2 L at 12 h. Colostrum high in Ig resulted in higher serum Ig concentrations at 48 h; the concentrations were highest when 4 L of colostrum high in Ig were fed to calves at birth.