EN
The aim of the study was to compare the effectiveness of calves infected with bovine leukaemia virus with that gained after the administration of FLK-BLV cells and lymphocytes of a leukaemic cow. The experiment was carried out on two groups of animals aged from 6 to 8 months. Each group of the cows was infected intravenously with the same dose of 1.2 x 105 FLK cells or lymphocytes. The third group involving two animals served as the control one. The sera of calves were tested at 2, 4, 6 weeks and 2, 3, 4 and 5 months after infection. The geometric mean titer of FLK infected calves was 3.9; 50.8; 101.6; 80.0; 64.0; 63.5 and 51.2 and in the group infected with lymphocytes - 0.0.; 511.6; 776.0; 2051.0; 1559.0; and 504.1, respectively. Serological examinations by means of the ELISA test revealed specific antibodies at two weeks after infection in the FLK group and at four weeks in the lymphocyte treated group. The highest titers were observed at six weeks in the sera of calves of the first group and at two months in case of the second group. It was found that the highest titer of antibodeis in the calves infected with lymphocytes was 20-fold higher than that of FLK cells infected animals.