Improved Tests on Productive Technology of Avian Infectious Bronchitis H(120) and W(93) Strain Living Vaccines

10-day and 12-day old Specific pathogen free (SPF) embryos were inoculated with different antigen concentrations of infectious bronchitis virus (IBV) H120 and W93 strains, incubated in different temperature, allantoic fluid were harvested in different post-incubated time and titrated, respectively. The manufactured technology of IB living vaccines were optimized according to numbers of early dead embryo,harvesting yields per embryo and antigenic titer of allantoic fluid. The results showed that the productive technology, with 12 day old SPF embryos inoculated with IBV contained 10~(2.7)EID_(50)/0.1 mL antigen concentration,and incubated 35 hours at 34.5 ,was better than productive technology previously. It greatly deduced the numbers of early dead embryo,increased harvesting yields from 8.37 mL to 12.4 mL per embryo.Meanwhile, the antigenic titer was enhanced to more than 10~(6.6)EID_(50)/0.1 mL.