A disease syndrome of broiler chickens is described. Affected birds exhibited poor pigmentation of the shanks, decreased weight gains, elevated feed conversions, poor feathering, enlargement of the proventriculus, and a decrease in the size of the gizzard. Reoviruses were isolated from affected chickens from several farms. Signs and lesions similar to those seen in chickens with the field syndrome were reproduced when these isolates were inoculated into day-old chicks with low levels of maternal antibody against viral arthritis. The pathogenicity of the viral isolates was variable. The incidence of lameness was much higher in those groups of chicks injected with these viruses than in the control groups.

A virus suspected of causing high death rates in fledgling budgerigars in Georgia and Texas aviaries was isolated in budgerigar embryo fibroblasts inoculated with tissue homogenates from affected birds. Virus was most easily recovered from tissues containing many intranuclear inclusion bodies. Cytopathic effect on fibroblasts of all four isolates was characterized by a swollen nucleus followed by rounding and detachment of the affected cell from the monolayer. Properties suggesting the B-931 isolate belongs to the papovaviridae family are (1) presence of DNA; (2) insensitivity to treatment with CHCl3; and (3) presence of cubic viral particles 42 to 49 nm in diameter in the nucleus of infected chicken embryo fibroblasts. The isolate did not hemagglutinate erythrocytes of chickens, turkeys, budgerigars, guinea pigs, or type O humans and was basically stable against heating and freeze-thawing. An examination of fledgling budgerigars from infected aviaries demonstrated that sick birds carried more virus than healthy birds.

SUMMARYOne-day-old chicks, with or without maternal antibodies against Newcastle disease, were vaccinated by different methods: one group received a live vaccine (Hitchner B 1 strain), the second group an oil-adjuvant vaccine, and the third group both vaccines simultaneously. The serological response and the protection of the chicks against challenge were evaluated regularly up to 80 days of age. The best results were obtained when using both vaccines, which induced a good level of protection against the challenge virus strain. INTRODUCTIONAlthough vaccination against Newcastle disease (ND) has been practised for many years, discussion is still taking place about the methods as well as programmes of vaccination. The recent use of inactivated oil-adjuvant vaccines (10 AV) (Zanella, 1966;Cessi and Nardelli, 1974;Allan, 1974;Bennejean et al., 1974) has been well-received by poultrymen owning flocks of breeders and laying hens. The interest in vaccinating pullets with IOAV before they start laying has been increasing.

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