Results of the implementation of sanitation measures in the farms unfavorable for bovine leukemia

Abstract

The dynamics of recuperation work on the example of two farms similar in economic and production and technological characteristics of the Novosibirsk region were studied. The data on leukemia at the time of the beginning of active recuperation work and the results after several years were presented. The infection rates of the livestock by different age groups and in different parts of the studied farms were analyzed for 2017-2022. The infection rate of cows on the farms tended to decrease slightly from 2017 to 2019 and was in the range of 8-4%. The infection rate of the heifers was 5-12%. Registration of new cases of serology response in the group of the calves in the farm No. 1 decreased from 9.9 to 4.9%, in the farm No. 2 from 14.2 to 7.1%. The positive dynamics of implementation of the recovery plan using enzyme-linked immunosorbent assay (ELISA) for serological diagnosis was shown. After switching from the immunodiffusion in agar gel reaction (AGID) to ELISA and its first use, the number of newly detected animals increased in all age groups in both farms compared to the previous period. In subsequent studies, the percentage of new cases decreased significantly. Physical separation of the groups of animals with different statuses, placing them in different sections and clear control with the immediate exclusion of infected animals from the production process led to a noticeable improvement in the epizootic situation on the farm. Aspects causing delay in sanitation work were noted, in particular, untimely separation of animals into groups after serological diagnosis and establishment of their infection status. Complete replacement of infected cattle in unhealthy herds or wards by groups of serology-negative animals can significantly reduce the recovery period, especially at the final stage.