[Incidence of antibodies against leptospira in the blood of breeding sows].

Within a year, 4438 blood sera of sows coming from 25 farms of the Strakonice district were subjected to serological examination by the reaction of microagglutination lysis (RMAL) with 12 strains of Leptospira. The reaction was positive in 3.22% of all the blood sera. Separate significant titres were demonstrated in the reaction with the Leptospira organisms of four serological groups, including Grippotyphosa, Icterohaemorrhagiae, Hebdomadis and Australis. The reactions with the Leptospira of the Canicola serological group were observed only individually as coagglutination with a simultaneous occurrence of antibodies to Leptospira of the Grippotyphosa serological group. The highest number of reactions 119 (75.8%) was demonstrated in titre 400.