AL-Qadisiyah Journal of Veterinary Medicine Sciences

Abstract

Field evaluation of Marek's disease infection in vaccinated parent flock
A. A. H.Zahid
Coll.of Vet.Med/ Univ.of Bagdad
Abstract
Field evaluation of natural infection with Marek's disease in vaccinated parent flock of broiler was studied. In this study two program of vaccination in two flocks were applied. the first flock was vaccinated intramuscularly at one day old only with bivalent Marek's disease vaccine. The second flock was vaccinated at one day old and revaccinated at 21 days old with the same route and vaccine. Both programs of vaccination were challenged by natural infection of Marek's disease at 8-10 weeks of age. Morbidity, mortality, clinical singes and pathological findings were recorded. Egg production and hatchability percent were also observed during the production period. This study revealed that the first program of vaccination had given high percent of mortality up to 34.38% while the mortality in the second program was 1.5 %; and females were more susceptible to Marek's disease than male birds. Egg production and hatchability percent were not affected both flocks