EVALUATION OF MATERNALLY-DERIVED ANTIBODIES AGAINST NEWCASTLE DISEASE VIRUS IN DAY-OLD CHICKS IN ABEOKUTA, OGUN STATE

Abstract

High maternally-derived antibodies (MDA) against Newcastle disease virus (NDV) in chickens can interfere with active immunity at early age. This study was conducted to assess the titre of MDA in chicks against NDV from two poultry breeder farms. Twenty-six blood samples were collected from day-old chicks randomly selected from two poultry breeding farms and forty blood samples were collected from the parent stocks of the same farms. The vaccination record of the parent stocks were collected while the antibody titres of the birds were estimated using Haemagglutination Inhibition (HI) test. The geometric mean titre (GMT) of MDA against NDV in chicks from Farms 1 and 2 were log 2^7.2 and log 2^7.4 respectively while the parent stocks from Farms 1 and 2 had log 2^7.7 and log 2^7.9HI units. The percentage of chicks from Farms 1 and 2 with MDA titre above protective level (>log 2³) were 90% and 100% respectively. It was concluded that MDA titres against ND virus was high in the chicks therefore vaccination at day one in the hatcheries and farms should be done after the immune status of the chicks are known since high MDA titre during vaccination neutralizes vaccine virus preventing active immunity.