Dynamics of immune response against Infectious Bronchitis Virus in broiler breeder

Abstract

Infectious Bronchitis Virus (IBV) causes respiratory disease in chicken. The virus is a highly contagious pathogen of poultry that causes very significant morbidity and mortality. A cross sectional study was conducted during February 2014 to identify the level of antibody (Immune response) against IBV in vaccinated broiler breeder flocks in Chittagong area, Bangladesh. A total of 460 serum samples were collected from twelve different flocks from a broiler breeder farm. The quantitative level of antibody was determined by indirect Enzyme Linked Immunosorbent Assay (ELISA). The geometric mean of titre of the vaccinated birds ranges from 1600 to 8143.Results also showed that the value of Geometric mean of titre of male of all flocks were greater than the female. The study also revealed the CV% (Coefficient of variation) of antibody titre against IBV of different flocksranges from 28% to 91%. The CV% of antibody titre of most of the flocks in case of female was higher than the male. On the otherhand, the sero-conversion of all IBV vaccinated flocks was 100% with the few exceptions. It can be concluded that the selected poultry farms have chosen the appropriatevaccines and optimal vaccination time which was providing better protection against IBV infections.