INTERACTION BETWEEN IMMUNITY TO BORDETELLA-BRONCHISEPTICA AND INFECTION OF PIG HERDS BY BORDETELLA-BRONCHISEPTICA AND PASTEURELLA-MULTOCIDA

The dynamics of toxigenic Bordetella bronchiseptica and Pasteurella mu ltocida infection and the B. bronchiseptica specific antibody content of the blood and nasal secretion were studied in three Hungarian and t hree Dutch pig herds. In both countries, the studies involved young so ws that had farrowed once or twice (YS), old sows that had farrowed mo re than four times (OS), and their piglets. The results indicate that Dutch sows are characterized by a lower prevalence of B. bronchiseptic a and P. multocida infection than Hungarian sows. In Dutch sows and in their piglets, the rate of P. multocida infection was higher than tha t of B. bronchiseptica infection. The opposite was found for the Hunga rian sows and their piglets. B. bronchiseptica infection commenced at 3 and 4 weeks of age in piglets of young and old Dutch sows, respectiv ely, followed by the emergence of P. multocida infection at 5 (YS) and 6 weeks of age (OS). In Hungarian piglets, B. bronchiseptica infectio n was first demonstrable at 1 (YS) and 3 (OS) while P. multocida infec tion at 3 (YS) and 5 (OS) weeks of age. The serological tests demonstr ated higher B. bronchiseptica specific antibody levels in the Dutch so ws and piglets as compared to the Hungarian ones. According to the ELI SA results, the levels of IgA and IgG in the serum and those of sIgA, IgA and IgG in the nasal secretion of Dutch sows were significantly (p <0.001) higher in the Dutch than in the Hungarian piglets up to 3 and 4 weeks of age, respectively.