Post-vaccinal reaction for some vaccines used against Newcastle disease in Sulaimaniyah province
This study was conducted to investigate the safety of the most commonly used Newcastle disease vaccines in Al-Sulaimaniyah province (LaSota and Clone30). A total of 225 one-day-old broiler chicks of Ross 308 breed were investigated for their maternal-derived antibody (MDA) titers by ELISA test. Subsequently, these chicks were divided randomly into 3 equal groups; ( 2 treatment groups, a T1 group which was vaccinated by LaSota vaccine and T2 group which was vaccinated by the Clone30 vaccine). and control non-vaccinated group. ELISA test was used to investigate the antibody titers against NDV in all groups on day 10 post second vaccination at 34 days of chicks age and tissue biopsies were obtained for histopathological examination from the trachea, spleen, Bursa of Fabricius and thymus to explore the tissue changes that may be induced by the vaccine. Significant variation was observed in the means of antibody titers against NDV between the control and treatment groups, whereas, no significant variation was observed between the treatment groups themselves. The histopathological examination results showed that a reactive lymphocytic response was observed in both treatment groups compared to the control group. In addition, focal epithelial sloughing and mucopurulent exudates were observed in the trachea of T1 group chicks only. The result of this study showed that the NDV vaccine of clone30 is approximate of the same efficiency and more secure than LaSota vaccine.