Prevalence of Bovine Leukemia Virus in Young, Purebred Beef Bulls for Sale in Kansas

A study was conducted to determine the prevalence of bovine leukemia virus (BLV) in young (less than 2 years of age), purebred beef bulls for sale in the state of Kansas, and to identify geographic differences in BLV prevalence within the state. Serum samples from young, purebred beef bulls submitted to the United States Department of Agriculture for brucellosis testing as part of Kansas state requirements for the sale of breeding cattle identified 2,520 samples that were sent to Kansas State University for analysis. From this population, 775 serum samples were randomly selected and tested for the presence of BLV antibody using an agar immunodiffusion assay. Sixty-six samples were positive for BLV, corresponding to a statewide prevalence of 8.5%. The state was divided into four quadrants and prevalence levels were compared to identify significant differences in BLV prevalence within the state. These differences are critically important to those developing risk assessments as part of a biosecurity program.