Vaccination of Broiler Breeders with a Tenosynovitis Virus Vaccine ,

An attenuated tenosynovitis virus was applied via the water to broiler breeders between 10 and 15 weeks of age to vaccinate against virulent tenosynovitis virus. Six flocks were vaccinated while two flocks served as unvaccinated controls. One of the unvaccinated control flocks subsequently developed gross and microscopic lesions of tenosynovitis. There was higher mortality in this flock than the other 7 flocks, but there was no difference in egg production. However, there were differences in parts condemned and total condemnations at the processing plant when progeny from the vaccinated and unvaccinated breeder flocks were compared. Also, in progeny from the unvaccinated flock, which was accidently infected with a virulent tenosynovitis virus, the mortality was much higher than in progeny from vaccinated flocks. Progeny from vaccinated breeder flocks withstood oral challenge with virulent tenosynovitis virus at 1, 3, 10, and 17 days of age much better (0 to 11% lesions) than progeny from unvaccinated breeder flocks (17 to 80% lesions). The progeny from the vaccinated flocks were also more resistant to subcutaneous challenge than progeny from the unvaccinated flocks.