author(s)
Nileshkumar Pagrut, Subha Ganguly, Sashi Tekam, Pawan Kumar Kawareti and Chandra Pratap Singh

abstract
A serological survey on the prevalence of antibodies to Newcastle disease (ND) virus was carried out in and around the District Kalyan. A total of 168 serum samples were collected from different commercial broiler farms and slaughter shops. Samples were divided into three groups according to the age i.e. 0-3 weeks (36 samples), 3-5 weeks (84 samples), and 5-7 weeks (48 samples). Haemagglutination inhibition (HI) test was performed to determine the serum antibodies against ND virus. Calculated geometric mean titres for groups 0-3, 3-5 and 5-7 weeks of age, were found to be 11.81, 10.61 and 15.39, respectively. The results showed that the level of protection of vaccinated birds was unsatisfactory.