Affiliation: | 1Avian Disease Division, National Veterinary Research and Quarantine Service, Anyang 430-757, Korea.;2Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, Seoul 143-701, Korea.;3Sam Hwa Breeding Agri, Boryeong 355-813, Korea.;4Merial Korea, Seoul 137-040, Korea. |