Immunogenic effect of bursal derived inactivated infectious bursal disease vaccine in layer chickens

摘要

The study was conducted to assess maternally derived antibodies (MDA) to infectious bursal disease (IBD), immune response of commercial chicks to inactivated bursal derived oil emulsified vaccine (OEV) and also immune status against IBD and Newcastle disease (ND) in IBD affected chicks. The MDA level showed wide variation between and within farms. The MDA completely waned by 21 days of age after vaccination on 7~(th) day of age. Hundred per cent seroconversion was noticed between 42 and 49 days postvacination (PV), and the peak titres were above the protective titre. IBD outbreak occurred in two commercial flocks. A significantly higher IBD and reduced ND antibody titres were observed during the convalescent phase of the outbreak.