الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Wild birds play a critical role in transmission of wide variety of viral diseases to poultry flocks worldwide, and considered as a natural reservoir of Newcastle disease virus (NDV). However, there is no available data about NDV genotype VII from wild birds especially in Egypt. For this purpose 240 samples were collected from (cattle egrets, sparrows and feral pigeons) in Kafrelsheikh Provence during the period (September 2017to October 2019). To identify the more prevalent NDV strain responsible for sever outbreaks in poultry farms.
The examined birds suffered from ruffled feathers, nervous signs and whitish green diarrhea with enteritis, congested pectoral muscles, lungs, liver and spleen with cloudiness of the air sacs. Successful amplification of (400 bp) of the fusion (F) protein by RT-PCR in 2 out of 28 pooled samples from cattle egrets (7.1%), 1 out of 10 pooled samples from sparrows (10%) and 1 out of 10 pooled samples from feral pigeons (10%). The identification of the isolated virus was genotype VII, subtype D. Phylogenetic analysis depending on F gene partial sequence clustered these isolates in genotype VII velogenic Newcastle with identity percentage of (94.9%) with NDV-chicken china-SDWF-07-2011. Histopathological study was carried out. Because of economical losses caused by ND disease, it was necessary to apply exact vaccination program in chickens as carried out. The protection efficacy of the commercial genotype VII NDV inactivated and live vaccines also evaluated when added to an existing commercial vaccination program against challenge. The results revealed that the combination of recombinant and live virus of genotype VII vaccines offered full protection (99.6) against challenge with isolated velogenic NDV in commercial broilers in comparison to inactivated genotype VII alone.