Epidemiology and financial loss estimation of blackleg on smallholder cattle herders in Kembata Tambaro zone, Southern Ethiopia

Background: Blackleg is one of the major bacterial infections causing tremendous economic losses to cattle herders in many parts of Ethiopia. Despite the huge burden, no comprehensive studies have quantified the impact or its distribution throughout the country. This study was aimed to estimate the epidemiological aspect of blackleg, financial costs and benefits of its control through annual vaccination on small holder cattle herders in Southern Ethiopia. Methods: Annual financial cost due to blackleg was calculated as the sum of production losses due to mortality, morbidity, treatment and vaccination costs at herd level. Production loss due to the disease was estimated and compared between local zebu and crossbred cattle. Partial budget analysis was used to estimate financial benefit of control intervention through annual vaccination. Results: An overall cumulative incidence and mortality rate of blackleg in local zebu cattle population was 17.9 % (95 % CI 16.5-19.4) and 3.6 % (95 % CI 2.9-4.4 %) respectively. Cumulative incidence and mortality rate attributed to blackleg in crossbreds cattle was 19 % (95 % CI 16.9-21.6) and 3.9 % (95 % CI 2.9-5.3 %) respectively. There was no statistically significant difference (p > 0.05) in both variables between the two breeds. Financial costs in blackleg infected herds was estimated to be USD 9.8 (95 % CI 6.7-14.4) per head for local zebu and USD 16 (95 % CI 10-24.4) per head for crossbred cattle. The marginal rate of return that could be obtained from the control intervention was estimated to be 9 (900 %) and the net benefit per head was USD 0.4 for local zebu and USD 0.8 for crossbred cattle. Vaccination, therefore, reduces financial losses due to blackleg by 3.4 and 6.9 % per head in local zebu and crossbred cattle herds respectively. Conclusions: The present study revealed considerable financial losses due to blackleg occurrence. The information obtained would be helpful to improve the farmers' livelihood and may open new avenues of research for the eradication and control of the disease at local and national level.