A total of 600 one-day old broiler chicks of two commercial breeds were used in a CRD design to compare performance and humoral immune response to Newcastle disease. Body weight and feed intake were measured weekly and at 42 day of age ten chicks were chosen randomly from each pen and slaughtered to determination of carcass characteristics. On vaccination day, 10 chickens selected randomly and were wing banded to monitor the antibody titer trend. There was no significant difference in body weight between studied strains. No significant difference was observed in feed intake and feed conversion ration between Arian and Lohman chicks. Lohman chicks had greater carcass weight and percentage than Arian. Abdominal fat weight was significantly (p< 0.05) higher in Lohman than Arian chicks. In both strains the antibody production increased by increasing the days after vaccination. In Arian chicks the increase was more pronounceable at 10 days after vaccination but Lohman chicks had highest antibody production at 15 days after vaccination. Strain effect was observed only at 10 day after vaccination and Lohman chicks showed greater antibody production against NDV vaccine than Arian (p< 0.05). It could be concluded from results that Arian and Lohman chicks has similar performance, but they show different immune response to NDV vaccine.
