Isolation and Progeny Transmission of Non-Temperature-Sensitive MS-H Vaccine Strains of Mycoplasma synoviae from Temperature-Sensitive MS-H-Vaccinated Laying Breeder Hens

This pilot study reports the vertical transmission and reverse thermosensitiv- ity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts + MS-H strain. At 9 weeks of age, an outbreak of infec- tious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were...