A comparison of commercial Mycoplasma gallisepticum antigens in the rapid serum agglutination test.

Twenty-three chickens, aged 9 weeks, were housed in contact with a similar group of chickens which were infected with M. gallisepticum. The onset and development of the serum agglutinin responses which were detected by 3 commercial antigens using rapid serum agglutination tests up to 20 weeks of age, differed greatly both between the infected and in-contact groups and, within the latter group, between the antigens. Few reactions, which were weak and transient, were detected in 2 similar groups of chickens, neither infected with M. gallisepticum but 1 vaccinated at 12 and 17 weeks of age with killed Pasteurella multocida oil adjuvant vaccine.