The efficacy of a fungal formulation based on the nematophagous fungus Duddingtonia flagrans was
assessed in the control of cattle trichostrongyles. Twenty male Nellore calves, six-month-old, divided
in two groups (fungus-treated and control without fungus) were fed on a pasture of Brachiaria decumbens
naturally infected with larvae of bovine trichostrongyles. Animals of the treated group received doses of
sodium alginate mycelial pellets orally (1 g/10 kg live weight, twice a week), for 12 months. Feces samples
were collected for egg count (eggs per gram of feces–EPG) and coprocultures during 12 months.
There was a significant reduction in EPG (56.7%) and infective larvae (L3) in coprocultures (60.5%) for animals
of the treated group in relation to the control group at the end of the study. There was a significant
reduction of L3 (64.5%) in herbage samples collected up to 0–20 cm from fecal pats and 73.2% in distant
samples (20–40 cm) between the fungus-treated group and the control group. The treatment with
sodium alginate pellets containing the nematode trapping fungus D. flagrans reduced trichostrongylid
in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode
in beef cattle.