Effect of neonatal immunoglobulin status on the outcomes of spring-born suckler calves.

Abstract

Successfully rearing beef calves to weaning and beyond determines the economic performance of a beef farm. As such, it is important to understand the factors influencing performance outcomes. This study recorded the health events, mortality and growth rates of 674 calves born on 50 commercial beef farms in Great Britain using a postsampling questionnaire. All calves had a known postcolostral serum IgG status. Preweaning mortality in the study population was 1.5% (10/674 calves), while the treatment rate was 6.4% (43/674 calves). Serum IgG, calf sex and dystocia were significant predictors of whether a calf died and/or required treatment. Average daily liveweight gain was calculated for calves where weaning weights were provided (n = 513). Serum IgG and calf sex were consistent predictors of calf growth rates, while birthweight and whether the calf was born to a cow or heifer were predictive in a model where average daily liveweight gain was converted to a binary response variable using the mean average daily liveweight gain on the calf's farm of origin. Morbidity and mortality were lower than comparable studies, potentially due to limitations in the study design. Serum IgG and calf sex were significant explanatory variables that affected beef calf average daily liveweight gain. For every 5g/L increase in serum IgG, the odds ratio of dying and/or requiring treatment decreased by 0.86.