Strain of Mycoplasma synoviae of low transmissibility.

An infection with Mycoplasma synoviae that spread slowly within and among pens of chickens was observed in a brown-egg breeding population that had long been free of M. gallisepticum and M. synoviae. There were unusually long periods of time between the first serological evidence of infection in a pen of chickens and the time that most of the group became positive. Transmission to adjacent pens was also slow.