Field Studies with Convalescent Serum and Infectious Bursal Disease Vaccine to Control Turkey Coryza

Abstract
Convalescent serum given to 1-day-old poults delayed clinical signs of turkey coryza by several days and reduced mortality on infected farms. Turkey breeders immunized with cell-culture-adapted infectious bursal disease virus (IBDV) or turkey (T) IBDV had a marked increase in virus-neutralization (VN) antibody titers. The VN antibody titer was significantly higher in progeny poults than in poults from unimmunized breeders. Clinical turkey coryza and mortality were considerably less in poults from IBD- or TIBD-vaccinated breeders than in control poults. They responded more favorably to hemorrhagic enteritis and fowl cholera vaccination.