Evaluation of the supply of Duddingtonia flagrans for the control of gastrointestinal parasites in sheep.

Abstract

Parasitic resistance imposes alternative control methods, like nematophagous fungi. In this study, two experiments were conducted supplying Duddingtonia flagrans aiming to evaluate the biological control of parasites in sheep. In the first, 24 sheep naturally infected by gastrointestinal nematodes were allocated, in randomized blocks, following the treatments: control or treated group, 0.5g/animal product containing D. flagrans, chlamydospores. Weight, body score, Famacha©, egg count per gram of feces (EPG), and larval percentage were evaluated. In the second experiment, D. flagrans (0.25 and 0.5g product) was infested with manure, plus or not protein concentrate, in a completely randomized design. In both experiments the dose was intentionally lower than recommended. Recovery and larval identification were performed. The SAS analyzed the variables by the MIXED procedure, repeated measures in time. Weight, body score, hematocrit, and Famacha© did not show differences between treatments (p>0.05); however, EPG (p<0.001) and the percentage of larvae identified in coproculture were different. In the second experiment, the inclusion of the fungus did not influence the recovery of larvae (p>0.05). In both experiments, colonization and advancement of the fungus were visualized. Under the experimental conditions, the fungus D. flagrans was not effective in the biological control of parasitic infection in sheep.