ANALYSIS OF RISK FACTORS FOR THE LEUKEMIA PREVALENCE IN CATTLE IN THE FARMS OF NOVOSIBIRSK REGION

Abstract

The analysis was carried out on the severity of the epizootic situation on leukemia and the presence of risk factors for the prevalence of this infection in 67 farms of Novosibirsk region, unfavorable for leukemia. Ten risk factors which can be attributed to the exogenous category of factors (technological, iatrogenic) were chosen as the subject of this study. These risk factors can have the greatest impact on the severity of the epizootic process in leukemia infection. The qualitative and quantitative representations of risk factors in the farms were analyzed, the most frequently registered of them were determined. The correlation between individual risk factors and such indicators as the level of leukemia incidence in cows and the infection rate of cows and heifers was assessed. It was established that there is a correlation between the leukemia incidence in cows and the following factors: the use of calves from cows with hematological diseases (p < 0.001) for reproduction of the herd; the absence of regular monitoring of the serological status of cows for BLV-infection (p < 0.001); the lack of regular monitoring of the serological status of cows for leukemia (p < 0.001); the use of natural insemination (p < 0.001). It was also identifi ed that there is a correlation between infection of heifers and joint maintenance and grazing of cattle with different status for BLV-infection (p < 0.001).