4Huchzermeyer F W. Ostrich Disease[M]. South Afirca: Agriculture Research Council, Onderstepoort Veterinary Insitute, 1994:11-12.
5Madeiros C. Vaccination of ostriches against Newcastle disease[J]. Veterinary Record, 1997, 140:188.
6Allwright D. Viruses encountered in intensively reared ostriches in southern Africa[C]//Proceedings of Improving our Understanding of Ratites in a Farming Environment. Oxford, UK. 1996:27-33.
7Verwoerd D J, Gerdes G H, Olivier A,et al. Experimental in fection of vaccinated slaughter ostriches with virulent Newcas tle dlsease virus[J]. Onderstepoort Journal of Veterinary Re search, 1997, 64:213-216.