Age Susceptibility of Chickens to Marek's Disease

Abstract

SUMMARY Chickens exposed to Marek's disease ( md ) virus either by contact or intra-abdominal ( i.a. ) inoculation of whole blood from infected donor chickens (GA isolate) rapidly became infected regardless of their age at time of exposure. At time of exposure, chickens were 1 day, and 5, 10, and 15 weeks old. The criteria used to determine infection included viral isolation from whole blood on chicken kidney cell ( ckc ) monolayers or direct cell culture of the kidneys, agar gel precipitin ( agp ) test, and gross lesions. Results of susceptibility experiments (based solely on mortality) indicated greatest mortality occurred in chickens inoculated or exposed when they were 1 day old.