
evaluation of tylosin in
preventing egg transmission of
mycoplasma gallisepticum in
chickens
the inoculation of mycoplasma gallisepticum infective
yolk into the left posterior thoracic air sac of laying chickens
resulted in an infection which produced a rate of egg infection
satisfactory for experimental purposes.  culturing of all live
embryonating eggs as well as all dead and infertile eggs was
necessary to determine the rate of egg infection.  tylosin,
either injected subcutaneously, administered in the drinking
water, or employed in an egg-dipping solution, greatly reduced
but did not completely eliminate egg infection.  in the 3 egg
dipping trials, only 11 isolates of m. gallisepticum were ob-
tained from 2329 tylosin-dipped eggs, compared to 400 isolates
from 2984 control eggs.
