Individual animal and maternal risk factors for morbidity and mortality of neonatal beef calves in Colorado, USA

Abstract

A prospective study was conducted to quantify the individual animal and maternal factors that affected morbidity and mortality of calves in Colorado beef herds. The study subjects were all calves born in ten participating herds during the 1990 and 1991 calving seasons. All 3666 calves born during the study period were individually identified at birth, and subsequent disease events were recorded by the producers. The disease outcomes of interest and their observed incidence rates were: perinatal (birth to 12 h) mortality, 2.5%; general neonatal (12 h to 45 days) mortality, 2.2%; general neonatal morbidity, 4.4%; neonatal diarrhea, 1.1%; neonatal respiratory disease, 1.0%; mothering problems/weak calves, 1.2%; and neonatal enterotoxemia/sudden death, 1.4%. Data analysis utilized multiple logistic regression. All analyses were adjusted for herd. Perinatal mortalily was greater ( P<0.01) for calves experiencing dystocia and for twin calves. The incidence of general neonatal morbidity was also higher ( P<0.01) among calves born to difficult or twin births, and calves of 2-year-old dams ( P=0.06). General neonatal mortality was higher ( P<0.05) among twins and calves of 2-year-old dams. Difficult or twin birth, as well as 2-year-old dam were the most common risk factors associated with the more specific morbidity outcomes. No evidence of the dam's late-gestation level of nutrition or seasonal effects on morbidity and mortality were observed.