Field Trials with an Oil Emulsion Newcastle Disease Vaccine in Broiler Breeders ,

Abstract

Chickens vaccinated with live Newcastle disease (ND) vaccine and subsequently revaccinated with an inactivated oil emulsion vaccine had high and persistent hemagglutination-inhibition (HI) antibody titers for at least 40 weeks. The geometric mean HI antibody titers of flocks vaccinated with the inactivated ND vaccine ranged from 48.8 to 91.9, whereas the titers of flocks vaccinated every 90 days with a live ND vaccine ranged from 8.6 to 43.5.Breeder flocks revaccinated with a live LaSota ND vaccine had lower egg production than the flocks vaccinated with the inactivated vaccine. The average egg production per hen for the 40 week laying cycle was 177.8 and 174.8 eggs per hen for hens vaccinated with the inactivated vaccine, whereas those hens vaccinated with the live virus vaccine averaged 163.0 and 155.6 eggs per hen. The increase in egg production would more than offset the additional cost of the oil emulsion NDV vaccine as well as the cost of injecting each individual bird at point of lay.Maternal antibody titers in one-day-old chicks were related to the titers in the dams. Maternal antibody titers in chicks originating from breeder flocks vaccinated with the oil emulsion vaccine were higher than the maternal antibody titers of chickens from breeders vaccinated with the live NDV vaccine.