Studies on The Role of Migratory Birds In The Epizootiology Of Newcastle Disease In Egypt

Investigation of the role of migratory birds in the opizootiology of Newcastle disease (ND) in Egypt was carried out. For this purpose, at total of 386cloacal swabs collected from 36 species of migratory birds of 26 genera and 13 families, trapped duringthe period from 16 September to 19 October 1976 at three northern sites of the Nile Delta (Bahing, BurgEl-Arab. and Iking Ma.rui t) J were examined for thepresence of Newcastle disease virus (NDV) by chickenembryo inoculation for 3 blind passages. Suspected inoculates, detected by the haemagglu-tination (HA) test in embryonic fluids of inoculatedeggs, were identified by the haemagglutinatio~inhi-bitian (HI) and virus neutralization (VN) tests USing known ND antisera.Certain biological and virulence characteristios of recovered isolates at the 4th egg passage levelwore also investigated. These included determination of the’ HA activity for 10 kinds of avian and mammalianerythrocytes; thermostability of haemagglutinin at 56oC,moan- death time (MDT) of minimal lethal dose (MLD) in9-day-old ohicken embryos; pathogenicity for 46 to6,·w8ok-old susceptible squabs by intramuscular (IM)