Prediction of calf mortality by use of tests for passive transfer of colostral immunoglobulin.

OBJECTIVE: To examine the ability of several commonly used tests for evaluation of passive transfer of immunoglobulin to predict mortality in dairy replacement heifers. DESIGN: Prospective observational study. ANIMALS: 246 dairy replacement heifers between 1 and 8 days of age. PROCEDURE: Using serum samples obtained from each calf, total serum protein concentration and results of zinc sulfate turbidity, sodium sulfite turbidity, radial immunodiffusion, and glutaraldehyde coagulation were determined. Calves were monitored for 100 days, and relative risks for death were calculated. Logistic regression models predicting death also were developed. RESULTS: None of the logistic regression models detected a significant association between test results and mortality. The greatest relative risks of mortality were observed in calves with serum protein concentrations < 4.5 g/dl, serum IgG1 concentrations < 500 mg/dl, and sodium sulfite test scores < 1+. CLINICAL IMPLICATIONS: Calves with lower passive transfer values had increased risk of death; however, failure of passive transfer is not an infallible predictor of mortality.