Antibody Responses against Newcastle Disease and Evaluation of Infectious Bronchitis Maternal Derived Antibody on Vaccinated Layers.

Abstract

Information of maternal derived antibody (MDA) and onset of immunity after vaccination is important to determine appropriate vaccination programme of chickens. The aim of this study was to evaluate duration of Infectious Bronchitis (IB) MDA and evaluate onset of immunity Newcastle Disease (ND) vaccination among layers. All layers were vaccinated using live ND and Infectious Bursal Disease (IBD) at one day old age, and received Avian Rhinotracheitis (AR) vaccine at 4 day old age. Serum samples were collected at various ages: 7, 10, 14, 20, 22, 24, 29 and 35 day old. The presence of ND antibodies was measured by the hemagglutination inhibition (HI) test, whilst the presence of IB antibodies was measured by enzyme-linked immunosorbent assay (ELISA). Our study showed that ND antibodies were at positive level until 24 day old age, and reached protective level ≥ 25 only at 7 day old age, whilst IB MDA were positive up to 17 day old age. This result indicating the needs of ND booster vaccination at least at 24 day old and IB vaccination at 17 day old age.