Between October 2018 and May 2019, a cross-sectional study was undertaken at an intensively managed dairy farm in Hossana town and Alage technical and vocational education and training college to evaluate the prevalence of bovine tuberculosis (BTB) using a comparative interadermal tuberculin test (CIDT) survey. In total, 384 cattle were studied, with an individual animal bovine tuberculosis prevalence of 25.78%. The prevalence differed significantly by breed (P=0.001), age (P=0.001), and body condition (P=0.041), but there was no significant relationship with the animal's sex (P=0.060). Similarly, the percentage prevalence of Bovine TB is higher in exotic breeds (25.06%), lower in cross breeds (0.52%), and lowest prevalence was found in local breeds (0.26%), Indicating higher susceptibility amongst exotic breeds and resistance amongst local breeds. Similarly, the prevalence is higher in adults (20%) than in young animals. Bovine Tuberculosis was found in 5.2% of animals with poor body condition, 10.16% of animals with medium body condition, and 10.42% of animals with good body condition during the study period. The test results were interpreted using a 4-mm cut-off specified by the Office International des Epizooties and a recently suggested 2-mm cut-off. Using the 4-mm and 2-mm cut-offs, the apparent individual animal prevalence of tuberculin reactors was 25.78 percent and 25.78 percent, respectively. The results of the comparative intra-dermal skin hypersensitivity reaction test revealed that the herd has more reactor cattle, which are the source of infection for the healthy or seemingly healthy cattle herd managed under the intensive system (close contact), and this is exacerbated by the lack of reactor removal and intermixing (poor quarantine) of previous test positive cattle. Pathological lesions should be employed on farms and in the countryside to prevent the spread of bovine tuberculosis.
Keywords: Bovine Tuberculosis, Purified protein derivatives, Comparative interadermal tuberculin test, Prevalence