الفهرس 
History, Incidence and distribution of the diseaseOnly 14 pages are availabe for public view
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Abstract
The epizootiological investigation of 21 current infectious bursal disease ( IBD) outbreks among vaccinated chickens flocks during 2011-2012 at 27-43 days of age these outbreaks were characterized by typical clinical signs and hemorrhagic gross lesions. the mortality rates in these flocks ranging between 4.9 -8% (average 6.45 %)in commercial broiler., 7.4-12.3 % (average 9.85%) in commercial layer replacement pullets and 7.4-13.2 % (average 10.3) in native baladi varieties, respectively.
IBDV was confirmed by detection of IBDV antigens by AGPT in bursal homogenates from acutely affected birds.Confirm the existence and circulation of vvIBDV in the field.
Our trail was designed to compare the immune response of HVT-IBD vector vaccine and IBD intermediate vaccine in commercial male layer chickens which revealed the early detected immune response of HVT-IBD vector vaccine by ELISA kits in the presence of MDA and protection of bursa against atrophy. No evidence of immunosuppressive effect of HVT-IBD vector vaccine on other poultry vaccine as ND and AI. HVT-IBDv vector vaccine protected commercial male layer chickens against mortality and against bursal damage and atrophy when challenged at 29 , 43 and 50 days of age with vvIBDV local field isolate ” Br./Men.Egypt/09” while commercial male layer chicken vaccinate with IBD intermediate vaccine showed 7% mortality when challenged at 29 and 43 day respectively, and no protection against bursal damage and atrophy with vvIBDV local field isolate ” Br./Men.Egypt/09” versus in non vaccinated group give 26% , 46 % and 60%mortalities when challenged at 29 , 43 and 50 days of age, respectively, vvIBDV local field isolate ”Men.Egypt/09”.