Longitudinal study of calf morbidity and mortality and the associated risk factors on urban and peri-urban dairy farms in southern Ethiopia

Abstract Background Calf morbidity and mortality are among the main causes of economic losses in dairy farms around the world. Poor calf management practices make the problem worse in developing nations like Ethiopia. This prospective longitudinal study was carried out in 70 dairy farms selected from southern Ethiopia with the aim of estimating the morbidity and mortality rates in calves and identifying the associated risk factors. To this end, a total of 274 calves were followed up every two weeks for major clinical health problems and deaths from birth to six months of age. Results The study revealed a morbidity rate of 12.7 cases and a mortality rate of 3.7 cases per 100 calf-months at risk in the study calves. The cumulative incidence of morbidity and mortality was also found to be 39.8% and 13.5%, respectively. Diarrhea was the leading cause of morbidity and mortality in calves, accounting for 71.3% and 62.1% of all morbidity and mortality, respectively. In a multivariable Cox regression analysis, the risk of morbidity was significantly (p < 0.05) lower in calves older than three months (HR = 0.22), female calves (HR = 0.57), calves raised by farmers who had completed secondary school (HR = 0.26) or college education (HR = 0.30), but it was significantly greater in calves born from dams affected with dystocia (HR = 2.4) and on farms where dairy farming is the farmers’ secondary source of income (HR = 1.7). Similarly, calves aged over three months (HR = 0.14), calves separated from their dams only after ingestion of colostrum (HR = 0.40) and owned by farmers who completed secondary school (HR = 0.08) or college education (HR = 0.13) all had lower mortality rates than other groups. Calves born to cows with dystocia were 5.2 times more likely to die. Conclusion The study concluded that calf morbidity and mortality rates in the study area are higher than economically tolerable levels and therefore it is recommended to raise awareness among farmers to improve calf management practices.