title: Viscerotropic velogenic Newcastle disease in turkeys: vaccination against loss of egg production.
abstract: Live B1 Newcastle disease virus was administered to young turkeys either intraocularly or by driniking water, or by both methods. Protection against egg production loss was evaluated by challenge-exposure to viscerotropic velogenic Newcastle disease virus in drinking water. During 22 days postchallenge (PC), none of the vaccinated hens had morbidity, whereas 44% of the unvaccinated controls died 6-13 days PC. Percent egg production (PEP) of all groups 1-5 and 6-22 days PC were compared with their levels 1-5 days before challenge. For days 1-5 PC, changes were not significant. For days 6-22 PC, changes for all groups were siginficant lower. The controls had 0 production. Hens vaccinated only at 4 days or at 4 days and again at 4 weeks averaged one-third or less of prechallenge levels but were recovering. Those revaccinated at 4 months maintained 84-91% of their prechallenge levels and were considered satisfactory. Broodiness was a detracting factor in one group of hens vaccinated at 4 days, 4 weeks, and 51/2 months. They averaged two-thirds of prechallenge levels but were in decline.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004531:Eggs; D005123:Eye; D005260:Female; D006385:Hemagglutination Inhibition Tests; D007267:Injections; D009521:Newcastle Disease / Q000276:immunology / Q000517:prevention & control*; D009522:Newcastle disease virus / Q000276:immunology; D014422:Turkeys; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000008:administration & dosage; D014867:Water
chemical_list: D014765:Viral Vaccines; D014867:Water