Effect of Passive Transfer of Immunity on Morbidity and Mortality of Calves in Pastoral Production System in Gursum District, Somali Regional State, Ethiopia

Abstract

A longitudinal study was conducted from November 2018 to May 2019 in Gursum pastoral production system, to determine passive
immunity status in newborn calves and to identify possible management factors that have contribution for the failure of passive transfer of immunity in cattle calves. The study further attempted to determine calf morbidity and mortality in relation with failure of passive transfer of immunity. From all calves belonging to the 150 households, each selected calf was individually ear-tagged and monitored on weekly basis for clinical health problems up to an age of three months. Mean total protein concentration of serum samples determined using spectrophotometer was 5.800 mg/dL and ranged from 2.76 to 8.34 mg/dL. The overall failure of passive transfer of immunity and adequate passive transfer of immunity status found in this study were 32.66% and 67.34%, respectively. Risk factors such as calf sex, dam parity, birth site, mothering instinct and age at first colostrum ingestion were found to have statistically significant effects (P= 0.004 to 0.032). Similarly, morbidity and mortality prevalence were significantly associated with serum total protein. Accordingly, 59.6%, and 5.1% of morbidity in complete failure and adequate transfer of passive immunity was found, respectively. On the other hand, 22.4% and 1.9% of mortality in complete failure and adequate transfer of passive immunity were observed, respectively. The incidence of morbidity and mortality was apparently higher in calves having complete failure than calves having adequate passive transfer. In this study, the highest proportion of failure of passive transfer of immunity might be due to improper calf and colostrum management practice and absence of regular care for pregnant cows. Hence improving knowledge of pastoralists concerning calf and colostrum management practice as well caring for pregnant cows and regular observation of pregnant cows would significantly reduce young stock mortality associated with failure of passive transfer of immunity.