Internal parasites in swine pose a significant challenge in organic pork production. This project documented populations of three leading parasites (large roundworm, Ascaris suum; whipworm, Trichuris suis; and nodular worm Oesophagostomum spp.) on nine organic farms in MN, IA, WI, and PA. Experiments were conducted to determine whether composting manure bedpack or growing a biofumingant crucifer (rapeseed) in pig pastures would reduce parasite numbers.

A. suum was by far the most common parasite in pigs from the nine farms, while T. suis and Oesophagostomum counts were minimal. A. suum did not affect pig growth but damaged their livers and posed a food safety risk. In laboratory studies, A. suum and T. suis eggs incubated at 136°F fail to develop into infective larvae. Composting reduced parasite egg counts in three summer trials, in which windrow temperatures exceeded 130°F for 4-8 weeks. In winter trials, windrows exceeded 130°F for less than 10 days, and egg counts were unaffected. Biofumigation did not affect parasite numbers, but rotational grazing on either clover or rapeseed pasture for four weeks (one week per paddock) reduced pig fecal egg counts (A. suum and T. suis). In addition, pasture soil egg counts declined three weeks after pigs were rotated out of the paddock.