[Mycoplasma synoviae control. II. Treatment of hatching eggs with tylosin tartrate (author's transl)].

Several strains of Mycoplasma synoviae isolated in the Netherlands during the past five years, were found to be sensitive to tylosin tartrate in vitro as well as in vivo. In one of four cases in which laying hens were infected experimentally, vertical transmission of the infective agent was demonstrated by the isolation of Mycoplasma synoviae from hatching eggs laid during the second and third weeks after infection. Treatment of experimentally infected eggs and eggs laid by infected flocks with 2.5 mg. of tylosin tartrate in the aircell on the ninth day of incubation resulted in the elimination of Mycoplasma synoviae. This procedure also underwent large-scale testing in the field. Injection of 0.8 and 1.5 mg. of tylosin tartrate into the albumen of non-incubated chicken eggs or turkey eggs through an area at a distance of approximately 1 cm. from the tapering extremity will probably provide an attractive alternative to egg-dipping in the control of mycoplasma infection.