A Study on determination of Antibody titer by HI test against Newcastle Disease in various layer flock In Chittagong district of Bangladesh.

Abstract

A serological survey was conducted to assess the level of serum antibodies against Newcastle disease virus by Haemagglutination inhibition (HI) test in layer birds in different areas of Chittagong district during November to December,2010. Six layer flocks were selected based on ages of birds. A total of 100 serum samples were collected and tested. Haemagglutination Inhibition (HI) test was performed using commercial Newcastle disease vaccine (Avinew®) as a source of 4HAU virus antigen. The Antibody levels against Newcastle disease virus (mean±SE) in 18, 73,77 weeks of ages were found, 9.88±0.34, 9.95±0.27, 8.80±0.77, respectively and in 40,43 and 58 weeks of ages were found 5.4±0.45, 8.08±0.33, 8.00±0.47, respectively. There was found lowest antibody titers at the age of 40 weeks. The average mean±SE of HI titer against Newcastle disease in layer flock indicates good and the investigated farms might be protective level against Newcastle disease.