Since the epidemic of Newcastle disease (ND) is becoming more and more complicated in recent years, the immune fail always take place in chickens. In order to prevent and control the epidemic of ND better in Luoyang district, the study had been done on the flowing six respects.
1. Identification of Newcastle disease virus isolates and their biological characteristics
Representative NDV strains collected during 1998~2002 in different parts of Luoyang area were isolated, identi...