Associated Conditions of ND Virus Multiplication in the Embryo

The multiplication of Newcastle disease virus(NDV) maybe affected by the maternal antibody,the age of embryo,the culture time,the dosage of inoculation,the seed of the virus,the multiple of dilute,temperature,humidity.Using the immunized embryo,we made the best association of the conditions for the multiplication of the NDV.In the ten-day-old embryos with the high maternal antibody(7log2-9log2) inoculated with 1∶ 1 000 -1∶ 5 000 NDV,the allantoic fluid output and hemagglutination(HA) titers attached the quite well extremum.