A Randomized Clinical Trial Evaluating Metabolism of Colostral and Plasma Derived Immunoglobulin G in Jersey Bull Calves

Pipkin, K.M.; Hagey, J.V.; Rayburn, M.C.; Chigerwe, M.

Mean calf weight AE SD for all calves was 29.8 AE 3.6 kg. Mean calf weight AE SD for the CL and PL groups was 30 AE 2.9 and 29.3 AE 4.2 kg respectively. There was no statistical difference in mean calf birth weight (P = .202) between the 2 groups. Mean IgG concentration for colostrum administered to the CL group was 6,780 AE 330 mg/dL. Thus, the mean dose of IgG fed to the CL group was 203,400 mg. Apparent efficiency of absorption for IgG was 24.8%. Thus, the mean IgG absorbed by the CL group was 50,444 mg. Mean AE SD IgG concentration for plasma administered to the PL group calves was 3172.9 AE 513.7 mg/dL. Thus, the predicted serum IgG concentration posttransfusion in the PL group using a mean weight of 29.3 kg, pretransfusion IgG concentration of 195 mg/ dL, mean plasma IgG concentration of 3172.9 mg/dL, and mean plasma administration volume of 997 mL (29.3 kg 9 34 mL/kg) was 1,308 mg/dL. Mean total IgG transfused to the PL group was 31,634 mg. One calf experienced an immediate transfusion reaction. Median (range) of serum total protein and serum IgG concentrations at different time points are presented in Tables 1 and 2 respectively. Median serum IgG concentrations for both groups were >1,000 mg/dL at 6 h but only calves in the CL group maintained serum IgG >1,000 mg/dL after 6 h ( Table 2) . Calves in the CL group had higher serum IgG concentrations compared to the PL group (P < .0001) at 48 h. All calves in the CL group had adequate transfer of immunity whereas all calves in the PL group had FPI at 48 h of age. Based on the general nonlinear regression model, the parameters for the models generated for the CL and PL groups are presented in Table 3 . The nonlinear models for the 2 groups are represented below: