Ζ. Dimareli-Mali, G. Xenos, Α.Papageorgiou, G. Papadopoulos

Two inactivated vaccines of colibacillosis of calves were evaluated. The first was prepared in our Institute and the second was a commercial vaccine. These two vaccines contained the antigen K99. The study was carried out in the American Agricultural Schoole in which twelve pregnant cows were vaccinated twice, at the seventh and ninth month of pregnacy (6 cows with the first vaccine and 6 with the second one). Five cows maintained as control animals. The antibody titres of K99 were determined using the serum agglutination test for the sera and colostrum of cows and calves. In both cases he K99 antigen and antiserum were used, which were prepared in our Institute. Our experimental data compared with findings in the literature indicate that the titres were satisfactory. However the continuing use of the vaccines in field with good results, confirm the laboratory results of our study.