A total of 20 buffaloes clinically positive for mastitis were selected for the collection of milk samples. The bacterial isolates i.e. Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli were isolated. At day 28, the geometric mean titer (GMT) of group D was 19.7, 16.0 and 32.0 for S aureus, Str. agalactiae and E. coli, respectively. In group E the GMT at day 28 were 48.5, 39.4, and 48.5 for S. aureus, Str. agalactiae and E. coli, respectively. In group F the GMT at day 28 were 64.0, 64.0 and 78.8 against S, aureus, Sir. agalactiae and E. coli respectively. The results of group D, E and F for assessing dose-dependent antigenic response showed that antigenicity of S. aureus, Str. agalactiae and E. coli was dose-dependent. There was direct relationship between antigen concentration and its antigenic response.