Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/24/2002
Publication Date: 11/10/2002
Citation: 83rd Research Workers in Animal Diseases Conference. 2002. Abstract No. 30.
Technical Abstract: A retrospective cohort study of 1568 beef calves was conducted to evaluate the association of serum IgG1 level, measured within 48 hours of birth, with preweaning and feedlot morbidity, mortality, and average daily gains. Logistic regression, analysis of covariance, and likelihood ratio tests were used to quantify effects on health and performance parameters. Calves with serum IgG1 levels at or below 2500 mg/dl were 1.5 times more likely to get sick before weaning (P equal to or < 0.05) and 2.4 times more likely to die before weaning (P equal to or < 0.05) than calves with higher levels of serum IgG1. Calves with IgG1 levels of at least 2700 mg/dl averaged 7.38 lbs more at 205 days of age than calves with lower serum IgG1, after adjusting for covariates (P equal to or < 0.05). No significant associations were found between serum IgG1 and feedlot morbidity, mortality, or average daily gains. These results present new evidence to substantiate other reports that initial acquisition of an adequate mass of colostral immunoglobulin is important in optimizing preweaning health and performance. Further, using likelihood ratio tests, the threshold of IgG1 for optimal health and performance of calves was found to be much higher than has been considered in previous reports.