In the present study, 3 pooled proventricular homogenates were collected from 3
broiler flocks, of chicken 15 to 30 days old, from Monofia Governorate. The 3 flocks
were suffered from low growth rate, poor feed conversion rate, uneven growth and
increased mortalities. Necropsy of dead chickens revealed proventriculitis with
increased proventriculus size. IBD viral antigen was detected in the pooled
proventricular homogenate of each flock by AGPT using reference antibodies against
IBDV and RT-PCR technique. No other viruses were detected; such as Reo virus,
CAV, NDV, IBV and ALV-J. Further characterization of the IBDV isolates were
conducted by RFLP assay on PCR products using MboI and BstOI restriction
enzymes. Results demonstrate that the 3 IBDV isolates are identical in their RFLP
pattern and related to the Del/E variant strain of IBDV.