Have you tried the primary cells culture (eg. chicken embryo fibroblast - CEF) for IBDV? You can prepare them from 10-days embryonated eggs. The IBDV differs in infection and growth kinetics in cell culture and it depends on virulence of strain. vvIBDV is difficult to propagate in CEF but they can be isolated in SPF eggs. You must considered what kind of IBDV you will be propagate and then choose the appropriate method for it.