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Atropic rhinitis (AR) is one of major respiratory diseases in pigs. AR causes a great economic losses and is considered to be a multifactorial disease in which herd management, heredity, and environment. Several vaccines against have been developed commercially and used in pig farms but the efficacy of each vaccine is still questionable. In this study, one of commercial AR vaccines, which contains inactivated Bordetella bronchiseptica, Pasteurella multocida type D and their toxoid was evaluated for vaccine efficacy by challenge test. Twenty piglets were divided into four groups as follows; group Ⅰ was piglets from vaccinated sows (twice before parturition); group Ⅱ was piglets from vaccinated sows (same as group Ⅰ) and were vaccinated at 1 day old; group Ⅲ and Ⅳ were piglets without any vaccination. Groups Ⅰ, Ⅱ, and Ⅲ were challenged by intranasal instillation of 5.3×10^7 CFU of B bronchiseptica twice and 1×10^9 CFU of P multocida five times. Group Ⅳ was control group without any vaccination and any challenge. We compared serological results, recovery rate of P multocida by polymerase chain reaction, clinical signs and pathological findings between vaccinated groups and unvaccinated groups for efficacy of the vaccine. Serological responses against B bronchiseptica and toxigenic P multocida type D were not showed evident discrepancy between vaccinated groups and unvaccinated groups assuming that the antibody responses against the vaccine is very delayed. However, growth rate, clinical signs and snout lesion grading in vaccinated groups showed more favorable than those in unvaccinated group. Therefore, AR vaccination in this study is considered to be effective in the prevention of AR in pigs.
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