Evaluation of a vaccine against Mycoplasma gallisepticum in commercial broilers.
The efficacy of live Mycoplasma gallisepticum (MG) vaccine against respiratory mycoplasmosis was studied in three laboratory trials with commercial broilers. Broiler chickens were infected with the F or R strain of MG by eyedrop at 1 day of age, and challenged by aerosol exposure to the R strain of MG along with eyedrop vaccination against Newcastle disease and infectious bronchitis at 30 or 34 days of age. Observations were made of macroscopic lesions, severity of airsacculitis, isolations of MG, serologic test results, clinical signs, and mortality. In all the vaccinated groups, the air-sac-lesion score was lower after challenge than in unvaccinated control chickens. After challenge the control group also had a higher number of MG isolations from the air sac than did the vaccinated chickens. There were no air-sac lesions observed in broilers before challenge in 2 of 3 trials.
D000400:Air Sacs / Q000382:microbiology / Q000473:pathology; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D001428:Bacterial Vaccines; D002645:Chickens; D009174:Mycoplasma / Q000276:immunology* / Q000302:isolation & purification; D009175:Mycoplasma Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D011201:Poultry Diseases / Q000382:microbiology / Q000517:prevention & control*; D014132:Trachea / Q000382:microbiology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines