Chronology of colonization of the nematophagous fungus Duddingtonia flagrans in sheep pastures

Grazing is a practical form of feeding for sheep, however, this practice faces problems, such as parasitism. Several forms of alternative control are used to manage the gastrointestinal helminth population in sheep, such as sustainable or alternative control. Nematophagous fungi constitute an important tool in this context, capable of preying on infective larvae directly in the soil. In this study, data from different periods were compiled to evaluate the colonization of the nematophagous fungus Duddingtonia flagrans in sheep pastures. The experiment began in 2021, using 26 Santa Inês sheep, distributed across eight paddocks (four control and four treated). The fungus was administered through a commercial product, at a dosage of approximately 0.5 grams per animal per day, for eight months, with continuous grazing. Forage samples were collected monthly and analyzed for the recovery of infective larvae, confirming the presence of the fungus from the third month of inoculation. After two years, in 2023, collections were carried out in the same area, again confirming the presence of the microorganism. In 2024, colonization was found in all paddocks. The means and standard deviations for the recovery of larvae in the treatments did not indicate significant differences between the years (>0.05), however, for the general means of recovered larvae, there was a difference (<0.001). Another factor observed was the gradual reduction in the number of total larvae year after year. The results of this study prove the efficiency of colonization of nematophagous fungi, especially Duddingtonia flagrans, in addition to their predation capacity and reduction of the population of parasitic helminths in the soil.