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.

Normality of data were checked using the Shapiro-Wilk test. In instances where the data was not normally distributed, the median was reported. Descriptive statistics were calculated for calf birth weight, IgG concentrations in plasma administered, colostral IgG concentrations, serum total protein, and serum IgG concentrations at different time points, serum IgG concentrations at 48 h of age (to assess passive transfer status), morbidity and mortality events between the 2 groups. Apparent efficiency of absorption of IgG was determined as previously described. 10 Serum IgG concentrations at 48 h between the 2 groups were compared using a Wilcoxon rank sum test. Calves with serum IgG concentrations <1,000 mg/dL were considered to have FPI. 6 Proportions of calves that died during the study period initially were compared between the 2 groups using a v 2 test or Fisher's exact test when a cell had <5 counts. A follow-up conditional step-wise logistic regression analysis was performed. The logistic regression predicted the probability of a mortality event in a calf as a function of group and medical treatment in sick calves. In the logistic regression, the final model fit was assessed using the Hosmer-Lemeshow Goodness-of-Fit test.