A study of effect of infectious bursal disease virus and vaccine on the humoral immune response to newcastle disease vaccine in broiler chicks

Abstract

The immune response on vaccination against Newcastle disease in broiler chicks is frequently reduced in case of infection with Gumboro disease or vaccination against Gumboro disease. The study aimed to study the immunological interference in broilers between infectious bursal disease viruses, live attenuated infectious bursal disease vaccine and live attenuated Newcastle Disease vaccine. One hundred and fourty commercial broiler male were selected in this study at one day of age. Fourty chicks were sacrificed randomly to measure maternal antibody titer against Newcastle disease virus and infectious bursal disease virus in their sera. One hundred chicks were divided randomly in to four equal groups. First group , Second group , Third group, were vaccinated against Newcastle disease virus vaccine LaSota strain by drinking water at (1,10,20,30) days of age. Furthermore, Second group was inoculated by infectious bursal disease virus at (28) day of age. Third group was vaccinated against infectious bursal disease virus vaccine (Winterfield 2512-G-61) strain by drinking water at (7, 14, 21, 28) days of age. The results obtained that there were a significant increase (P<0.05) in the mean titer of first group in HI test at (23rd) and (33rd) day of age. The results of indirect ELISA showed that there were a significant increase (P<0.05) in the mean titer of antibodies against Newcastle disease virus of first group at (35) day of age. The results revealed a significant decrease (P<0.05) in the mean values of HI test against Newcastle disease virus of the second and third groups at (23rd) and (33rd) day of age. . It is concluded that the humoral immune response against Newcastle disease virus was influenced directly due to the immunological interference of field and vaccinal strains of infectious bursal disease virus.