Epizootic zoning of the Omsk region according to the spread of cattle leukemia

Based on the results of diagnostic studies using the immune diffusion reaction (IDR) and the hematological method, an analysis of the epizootic situation of cattle leukemia in the Omsk Region in 2014-2018 has been carried out. It has been found out that there is a tendency towards an increase in the number of bovine leukemia virus (BLV) infections from 10.7% in 2014 to 16.8% in 2018. The percentage of infected cattle during this period remained practically unchanged and amounted to 0.3-04%. In all 32 districts of the Region BLV cases were registered, while the level of seroprevalence varied widely, for example from 2% in Sedelnikovo District to 42.9% in Cherlak District in 2018. Sick cows in the hematological stage of leukemia were found only in 13 districts. During the next stage of the current research, in order to visualize the degree of leukemia infection spread across territorial units epizootic zoning was carried out with the help of newly elaborated computer program that allows to evaluate the studied parameters, then data were ranked according to their significance level (high, medium and low) and put on outline map. With the help of the epizootic zoning, territorial units with high spread of BLV were identified - over 30%, with average spread - from 10% to 30% and low spread - up to 10%. According to the results of serological studies for 2018, 6 districts were included in the first group, 16 in the second group and 10 in the third group. The ranking of territorial units for the manifestation of leukemia in the hematological stage made it possible to identify areas with the following figures: up to 0.3% of sick animals (Kalachinsk, Lyubino and Sedelnikovo Districts); from 0.3 to 1.0 (Kormilovka, Moskalenki, Novovarshavsk, Russkaya Polyana, Tara, Tevriz and Sherbakul Districts) and more than 1.0% of sick cows (Maryanovka, Pavlogradka and Ust-Ishim Districts).