[Experiments with vaccination against infectious epididymitis in rams].

Two killed vaccines were produced, differing by the adjuvant used--a hydroxide one and an oil one--employing four strains of Brucella ovis. They were applied twice at an interval of 20 days to rams under experimental conditions as well as to rams in filed conditions. On the 45th day following vaccination the experimental rams were challenged with a virulent Brucella ovis strain. To determine the acquired resistance the rams were investigated after the complement-fixation test, hemagglutination reaction, and agar gel immunodiffusion as well as through clinical and bacteriological examination of sampled semen for the presence of bacteria. It was established that rams treated with an oil vaccine built up a solid immunity. The postvaccinal antibodies disappeared after the third month of vaccination. It is suggested to carry out vaccinations with rams of the infected flocks each 6 months. The infected animals can be identified by means of serologic examination three months following vaccination. Vaccination makes it possible to use valuable animals for a longer period, which, though infected are not hazardous in spreading the infection in the flock. A programme is referred to for the curing of flocks by means of vaccination applied to the intact rams and gradual elimination of the infected animals.