Vaccination Of Broiler Breeders Against Infectious Bursal Disease: Seroconversion, Progeny Protection And Impact Of Breeder Revaccination With Live Vaccines

Montiel E. | 16th WVPAC Marrakesh | 2009


Commercial broiler breeders were vaccinated at one day of age with a HVT-IBD vector vaccine. One group received HVT+SB1 vaccine to serve as control. At 20 weeks of age, the birds were divided in groups and vaccinated with various inactivated IBDV vaccines. Serum samples were collected at 20, 26, 30, 40, 50 and 60 weeks of age and tested for IBDV antibodies using the ELISA and virus neutralization (VN) test. When the breeders were 30 and 50 weeks of age, progeny from the various breeder groups were challenged with pathogenic IBDV isolates at 14 days of age to evaluate maternal immunity. Protection against challenge was evaluated by calculating the bursal: body weight ratio 7 days after challenge. Serum samples and broiler chicks from a breeder flock vaccinated with a typical IBDV program were included in the study as an industry reference. At 60 weeks of age, the IBD-vaccinated and unvaccinated breeders received a live IBDV vaccine. Serum samples were collected 4 and 8 weeks after vaccination to measure IBDV antibodies using the ELISA and VN test. All the progeny from breeders that received the HVT-IBD vector vaccine showed superior protection against challenge with the various IBDV isolates tested (Table 1). The vectored vaccine-vaccinated hens had increasing levels of IBDV antibodies between 20 and 60 weeks of age while IBDV antibody levels decreased by 50 weeks of age in birds vaccinated with typical commercial programs.