EFFECT OF GENETIC SELECTION FOR INCREASED BODY-WEIGHT AND SEX OF POULT ON ANTIBODY-RESPONSE OF TURKEYS TO NEWCASTLE-DISEASE VIRUS AND PASTEURELLA-MULTOCIDA VACCINES

Primary and secondary antibody responses of 671 turkeys of two genetic lines to Newcastle disease virus (NDV) and Pasteurella multocida vacc ines were examined. The randombred control line (RBC2) and a subline ( F) of RBC2 had been selected for increased 16-week body weight. Poults were vaccinated at 6 and 12 weeks of age, and serum samples were coll ected 3 weeks after each vaccination. Antibody titers were determined using an enzyme-linked immunosorbent assay. Line F turkeys had signifi cantly higher 9-week and 15-week serum antibody titers to NDV than lin e RBC2. However, line RBC2 had significantly higher serum antibody tit ers to P. multocida at 15 weeks of age than line F. The 9-week and 15- week serum antibody titers to NDV were significantly higher in females than males, but males had significantly higher 15-week serum antibody titers to P. multocida than females. Sex of poults did not contribute significantly to variation in serum antibody response to P. multocida at 9 weeks of age.