[Effects of Mycoplasma synoviae infection on the state of health, reactions to vaccination and results of fattening in broiler chickens (author's transl)].

Four cases in which contact infection was experimentally induced in broilers by Mycoplasma synoviae (M.s.) are reported. The chickens were inoculated against Newcastle disease (NCD) and infectious bronchitis (IB) in accordance with the Netherlands vaccination programme. Fattening was continued for six weeks. The rate of horizontal transmission of M. synoviae infection varied with the severity of the virus infection (i.e. vaccination). There was a close correlation between this finding and the adverse effects of M. synoviae infection on the severity of the reactions to vaccination, the final weight, the table quality and feed conversion. Moreover, there was evidence to suggest that M. synoviae accelerates the appearance of dyschondroplasia in broilers.