The aim of this study was to determine the causes and identify the risk factors associated with pre-weaning mortality in four dual-purpose bovine herds in Colima, Mexico. Four herds were selected and births and deaths were recorded for 12 months. Information was collected on the calving number of the dam and the sex of the calf. Necropsy was performed in cases of death. Data were analyzed using the Chi-square test and logistic regression. The pre-weaning mortality rate was 4.30%, with half of the deaths occurring within the first 48 hours after birth, especially due to dystocia (50%) and congenital abnormalities (25%). A significant association was found between herd mortality and the number of calving of the cow (p<0.05), but not with the sex of the calf. Calves born in herd C were 4.60 times more likely to die than those born in the other three herds, while calves born to multiparou...

The study evaluated the causes and risk factors associated with pre-weaning mortality in extensive and semi-extensive lamb production systems in a municipality in the coastal region of the state of Colima, Mexico. Mortality was assessed by necropsy and information on the number of births and the body condition of the ewe before lambing, litter size, sex, breed and weight of the lamb was recorded at the time of lambing. Statistical analysis was done using the Chi-square test of independence and by means of stepwise Logistic Regression. The overall pre-weaning mortality rate was 27.9%. The number of lambs born and dead was 875 and 244, respectively, where 88.1% of the mortality occurred during the first 48 hours of birth due to starvation-exposure syndrome. Pre-weaning mortality was significantly associated (p<0.05) with the flock, body condition of the ewe at parturition and with the l...