Research has shown that nematode-trapping fungi are effective against the worm larvae in livestock feces. These fungi are found naturally in environments that are rich in organic matter where they produce a variety of mycelial structures (the vegetative part of the fungus) that trap, destroy, and feed on non-parasitic soil worms. A commercial source of these fungi, specifically Duddingtonia flagrans, are sold in the United States as BioWorma^® or Livamol^® with BioWorma^® currently sold through Premier 1 Supplies. Spores of D. flagrans are fed to livestock, pass through the ruminant gastrointestinal tract intact and are deposited in the feces on pasture. Then, D. flagrans spores germinate. The mycelia grow rapidly into sticky, sophisticated traps/loops that trap and digest the developing worm larvae. These larvae emerge from worm eggs within the fecal pat alongside the fungus, but because they are trapped and killed by the fungus, they remain in the fecal pat (do not escape to the environment).

The fungus does not have any effect on existing worms in the animal, reduce fecal egg counts, or improve anemia. Instead, it reduces the number of infective larvae on pasture. You may see improvements after long-term feeding of the fungus while also using other methods described here to control worms in the animals. The fungus does not naturalize and persist in the environment; it must be supplied continuously, though only during warm, humid conditions, during late pregnancy/early lactation, and when susceptible lambs or kids are grazing.

The fungus can be fed in the feed or mixed in a trace mineral mix for flocks/herds that do not provide grain supplement. The fungus can safely be mixed with coccidiostats for control of pasture worms and coccidia in the animal. For more information see the fact sheet Worm-Trapping Fungus.