The Effect of Vaccinating Turkeys with the Clemson University Strain of Pasteurella multocida on Subsequent Reproductive Performance and Longevity of Immunity

Abstract

Turkeys were vaccinated at 12 weeks of age with a commercial fowl cholera bacterin. At the time of housing (32 weeks) they were divided into three treatment groups. One group was vaccinated orally with a 16 to 18 hour brain-heart infusion broth (BHI) culture of the Clemson University (CU) strain of Pasteurella multocida. The other two groups, received BHI broth and water alone, respectively. No vaccine associated mortality was observed.Vaccination at time of housing had no adverse effects on reproductive performance in that no significant differences were observed among treatments in the percent hen-housed or hen-day egg production, egg weight, percent of fertile eggs or percent hatch of fertile eggs, mean hen body weight or mean daily feed consumption. However, hens given the CU vaccine and those given water alone had significantly less hatch of total eggs set than those given BHI broth alone.After 28 weeks of production, hens from each treatment group were orally challenged with virulent P-1059 strain of P. multocida. The survival rate of hens after challenge was significantly higher in the CU vaccinated group (75%) when compared with either of the other groups given BHI broth (18%) or water (12%). These results suggest that even a single vaccination of adult turkey hens with the CU vaccine may afford significant protection from fowl cholera for as long as 28 weeks after vaccination without adverse effects on reproductive parameters.