Spreading of bovine leukemia virus among cattle in the Poltava region

Abstract

The problem of the bovine leukemia virus remains relevant all over the world. In Ukraine, farms in various regions are constantly registered that are unfavorable concerning bovine leukosis. The purpose of our research was to analyze the spreading of the bovine leukemia virus based on the results of diagnostic measures for leukemia among cattle in the Poltava region. To achieve the specified goal, we performed the following tasks: to examine laboratory samples of cattle blood serum from the farms of the Poltava region; to analyze the data of laboratory studies on leukemia, carried out earlier. There were determined the results of research diagnostics enzootic bovine leukosis in livestock farms of the Poltava region during 2020–2021. Planned studies of blood serum samples from cattle of livestock farms for the detection of antibodies to the leukemia virus were carried out by the enzyme-linked immunoassay (ELISA) in the immunological department of the Regional State Laboratory of the State Production and Consumer Service in the Poltava region. Planned studies of blood serum samples from cattle from private sector households for the detection of antibodies to the leukemia virus were carried out only by the agar gel immunodiffusion reaction (AGID). We established that for two years, samples of blood serum from 275,517 heads of cattle from farms of the Poltava region were examined, in particular, in 2020 – 169,368, and 2021 – 106,149 samples. The number of planned studies on bovine leukemia of blood serum samples from farms of the Poltava region in 2021 was 1.6 times less than in 2020. The decrease in the number of examined samples is associated with decreasing the total number of cattle. During two years, 1,030 animals infected with the bovine leukemia virus were found in the Poltava region. In particular, 799 sick animals were detected in 2020, and 231 animals in 2021. Therefore, the incidence of leukemia in cattle in the region was 0.47 % in 2020, and 0.22 % in 2021. Thus, in 2021, compared to the previous year, a 2.14-fold decrease in the incidence rate of leukemia was noted. The decrease in the incidence rate in 2021 occurred as a result of a review of the system of supervision and control over compliance with plans for the elimination of bovine leukemia in the region.