Abstract
<jats:p>This article provides a comprehensive analysis of the spread of bovine leukemia virus (BLV) and evaluates the effectiveness of integrated veterinary and sanitary measures implemented in farms of the West Kazakhstan region specializing in Black-and-White cattle breeding. The study included clinically healthy animals, cows with positive agar gel immunodiffusion (AGID+) test results, and animals diagnosed with leukemia. To assess the epizootic situation, a detailed analysis was conducted of herd structure, the ratio of infected to healthy animals, housing and feeding conditions, reproductive characteristics, as well as overall farm management and production practices. Serological (AGID) and hematological diagnostic methods were applied to ensure timely detection of infected animals and virus carriers. As part of the health management program, AGID-positive animals were isolated and gradually removed from the herd, while offspring from infected cows were reared separately under strict biosecurity measures. In addition, strict control was maintained over animal grouping, movement, artificial insemination, disinfection procedures, continuous veterinary monitoring, and preventive measures. These measures were designed to break the chain of infection, eliminate virus sources, and enhance overall livestock productivity and safety. The results from 2023 to 2025 demonstrated a consistent decrease in infection rates according to both AGID and hematological indicators. The significant reduction in the proportion of AGID-positive animals indicates a clear decline in disease spread, confirms the high effectiveness of the implemented measures, and contributes to improved epizootic safety and herd health management. At the same time, several organizational and economic challenges were identified, including insufficient isolated housing, a shortage of trained personnel, and the need to provide separate equipment for different animal groups. Overall, the findings confirm that a comprehensive, science-based approach is highly effective in controlling bovine leukemia and highlights its substantial practical importance for improving herd health, biosecurity, productivity, and sustainable livestock production.</jats:p>