RECOVERY OF OESOPHAGOSTOMUM-DENTATUM FROM PIGS BY ISOLATION OF PARASITES MIGRATING FROM LARGE INTESTINAL CONTENTS EMBEDDED IN AGAR-GEL

Four groups with three pigs in each group were inoculated with Oesopha gostomum dentatum larvae (L(3) larvae), Groups 1 and 3 were inoculated with 20 000 larvae, and Groups 2 and 4 with 200 000 larvae, On Days 1 1 and 34, respectively, Groups 1 and 2 and Groups 3 and 4 were slaught ered, and the contents from the large intestines collected. Subsamples of intestinal contents were mixed with agar to a final concentration of 1% agar and allowed to set. The worms were allowed to migrate from the agar-gel into 38 degrees C 0.9% saline overnight. Then the worms w ere collected on a sieve (38 mu m mesh) and counted. The worms retaine d in the agar-gel were counted after pouring the melted agar through a sieve (38 mu m mesh), The results showed that more than 95% of the wo rms migrated out of the agar-gel, and subsequently were available for counting in an almost clean suspension, Additionally the method yielde d a high worm recovery; all stages were recovered. The recovery percen tage was not significantly affected by either the dose of parasites or the time interval from slaughtering to start of incubation (37-128 mi n).