EN
Eighty cross bred, 4 week old pigs were randomly divided into 4 equal groups. They were used to test whether protection stimulated by immunizing infections of A. suum treated with pyrantel tartrate to prevent larval migration is similar to that achieved when larvae were allowed to migrate normally. The effects of the various immunization procedures on the pigs immune performance were also studied. The degrees of protection against larvae and adults were significantly higher in pigs immunized by infections where the migration of larvae was prevented by pyrantel tartrate. Infections where migration of larvae was not prevented by pyrantel tartrate resulted in immunosuppression as measured by antibody titre against chicken red blood cells and a lower response of peripheral blood lymphocytes to Concanavalin A.