Journal of the Japan Veterinary Medical Association

Salmonella organisms contained in cooling water nsed at the chicken-dressing plant were destroyed by exposure to 50 to 100ppm of effective chlorine for 5 to 10minutes when the amount of organic matter dissolved in the water was less than 20mg per 100ml. This procedure was also effective against the secondary contamination of water at large, fingers, and utensils with these organisms.

View full abstract

Show abstractHide abstract

Five lots of a mixed live vaccine were prepared tentatively from theexisting commercial hog cholera (HC) live vaccine and swine erysipelas (SE) live vaccine by the freeze-drying method. Each of them contained a HC virus titer of 10^2.7-10^3.8TCID₅₀/ml and a viable SE bacterial count of 3.1-9.0×10₈cells/ml. Such titer and count were hardly reduced during a storage at 4°C for 15months. Three-week-old mice inoculated intraperitoneally with 1ml of the mixed vaccine and pigs subcutaneously with 10-20ml withstood infection. Pigs inoculated subcutaneously with 1ml of the mixed vaccine withstood challenge inoculation with high virulent HC virus 2weeks later, and with high virulent SE bacilli 3-10 weeks later. In them, HC neutralizing antibody began to be detected 2-3weeks later and viable SE bacteriaagglutinating antibody 1 week later. The former retained a titer of 32-256 and the latter a titer of 16-32 even 6 months later. Pigs inoculated with the mixed vaccine in a field trial presented no abnormal signs at all. When examined a month after inoculation, 93.7% of them showed an increase in titer of HC neutralizing antibody and viable SE bacteria-agglutinating antibody, the former ranging from 32 to 256 and the latter from 16 to 128. These results seem to indicate that the mixed vaccine may be available for practical field use.

View full abstract

Download PDF (3321K)

Register with J-STAGE for free!