Establishing presence and status of infection with bovine diarrhoea virus in cattle herds in central Serbia – possibilities for control

The objective of our investigations was to determine the presence and status of infection with the bovine viral diarrhoea virus (BVDV) and to identify persistently infected (PI) cattle in 4 herds (experimental groups): 2 with fattening heifers (10 and 13 animals) and 2 with dairy animals with offspring older than 4 months (23 and 16 animals). Two series of blood samples were taken in an interval of 4 weeks (even samples) from all the animals, from each experimental group. Separate blood serums from both groups of samples were examined using the indirect ELISA method (HerdChek* BVDV Ab test kit). The results obtained in our investigations indicate the presence of infection with the BVD virus in the experimental animals. Blood serum samples taken on the first day of investigation were seropositive in 7 experimental animals of the first group, in all (n=13) experimental animals of the second group, seropositive in one and suspect in 2 animals of the third experimental group, and seropositive in one and suspect in 3 experimental animals of the fourth group. Blood serum samples taken on the 28th day of the examinations were seropositive in one, thirteen, two, and three experimental animals of the first, second, third, and fourth experimental groups. Serum samples of animals (n=29) that were established as seronegative in both investigations (on the first and the 28th day) were examined for the possible presence of antigen to the BVD virus using the ELISA method (HerdChek* BVDV Ag/Serum Plus) with the objective of investigating the presence of PI animals. The presence of antigen to the BVD virus was not established in the examined cattle. On the grounds of the results of the investigations and data in literature, measures for controlling BVDV infections were recommended to animal owners.