Molecular prevalence of Bovine Leukemia Virus in specialized dairies in the department of Antioquia, Colombia

Dairy production systems are a sensitive sector of the primary economy frequently affected by pathogens that negatively impact production parameters, the bovine leukemia virus (BLV) one of these. In this study, the molecular prevalence of BLV was determined in the specialized dairy sector of Antioquia using the viral marker of the envelope gene (env). Blood samples were taken from 575 bovines from specialized dairies in Antioquia distributed in 53 herds and located in the three specialized milk production areas of Antioquia (north, east, and Valle de Aburrá). DNA extraction was performed by salting out, and a nested PCR was performed to detect the env gene. The products were visualized on a 2% agarose gel with GelRed as an intercalator. A molecular prevalence of BLV of 17.0% in animals and 71.7% in herds were found, being Valle de Aburrá the area where the highest rate of positive animals was obtained (21.1%), unlike the northern area with the lowest rate (15.6%). The molecular prevalence of BLV in this study is lower than that of previous studies in the department, which ranged between 47 and 73%, and this may be associated with factors of breed resistance, the age of the animals, or management practices in the herds. These results can contribute to creating BLV control strategies and optimizing milk production in the department of Antioquia, being relevant to paying attention to the behavior of this pathogen under different production system conditions.