Multivariable linear regression showed that the addition of GAC to CR did not influence passive transfer of IgG, as measured by apparent efficiency of absorption at 24 h of age (CON = 54.0 vs. GAC = 54.3%), serum IgG (CON = 20.3 vs. GAC = 20.2 mg/mL), and serum total protein (CON = 5.69 vs. GAC = 5.68 g/dL).