Abstract
In summer 2006, splenomegaly and splenic mottling of brand meat chickens were observed, when 0.53-1.88% of birds were condemned for a typical Marek's disease. In summer 2007, a similar condition was observed and 50 spleens obtained at slaughter from one of the flocks were examined. Histologically, reticuloendothelial cells hyperplasia with intranuclear inclusion boies were observed and ultrastructurally, adenovirus particles were detected. A PCR assay showed that the spleens were positive for the hexon gene of group Ⅱavian adenovirus (GⅡAAV). The sequence of the PCR product was identical to the avirulent turkey hemorrhagic enteritis virus strain Virginia with 97.3% homology. The extract of the above spleens was inoculated intravenously in 8-week-old chickens. Four days post inoculation, splenomegaly was observed and the spleen,thymus, and bursa of Fabricius were positive for the GⅡAAV gene.
