Foot and mouth disease (FMD) and infectious bovine rhinotracheitis (IBR) are two important infectious diseases of cattle. Inactivated FMD vaccines are the most powerful tools to protect animals against FMD. Previous studies showed that recombinant IBR-FMD viruses protected cattle from virulent BHV-1 challenge and induced protective levels of anti-FMDV antibodies. FMD is considered to be endemic in Turkey and inactivated oil adjuvanted vaccines are used for the immunization of cattle. Previous studies showed that seroprevalence of IBR in the Turkey’s dairy herd more than 50%. In this study, antibody response in IBR seropositive cattle following vaccination against FMD was investigated. IBR seropositive (n=208) and IBR seronegative (n=212) cattle were vaccinated with oil-adjuvanted bivalent vaccine (containing O₁ Manisa, A₂₂ Iraq FMDV strains). Solid-phase competitive ELISA (SPCE) was used to measure antibodies produced in cattle. Protective level of antibody against serotype O was detected in 77.4% and serotypes A in 83.6% of IBR seropositive cattle. Protective level of antibody against serotype O antibody was detected in 49% and serotypes A in 66.9% of IBR seronegative cattle. The differences between the protection rates against both serotype O (P=0.0001) and serotype A (P=0.0001) in IBR seropositive and seronegative animals were statistically important (Fisher’s exact test, P<0.01). Results showed that after FMD vaccination, IBR seropositive animals produced high titres of antibodies than seronegative animals.

Key words: Antibody response, Foot and mouth disease, Infectious bovine rhinotracheitis, Vaccination