Coadministration of Nematophagous Fungi for Biological Control over Nematodes in Bovine in the South-Eastern Brazil

This study compared the coadministration among the three nematode predatory fungi, Duddingtonia flagrans, Monacrosporium thaumasium, and Arthrobotrys robusta, in the biological control of cattle gastrointestinal nematodiasis in comparison with the use of the fungus D. flagrans alone. Five groups consisting of eight Girolando heifers were kept in paddocks of Brachiaria decumbens for six months. Each heifer received 1 g/10 kg of pellets containing the fungi (0.2 g of fungus/10 kg b.w.). Group 1 (G1) received pellets with D. flagrans and M. thaumasium in coadministration, G2 received D. flagrans and A. robusta, G3 received M. thaumasium, A. robusta, and D. flagrans, and G4 received the fungus D. flagrans alone. Group 5 (control) received pellets without fungi. The monthly mean of fecal egg count (FEC) of Groups 1, 2, 3, and 4 were 93.8, 85.3, 82.7, and 96.4% smaller than the mean of control group. The treatments with pellets containing D. flagrans or D. flagrans + M. thaumasium produced significantly better results than the D. flagrans + A. robusta or the combination of the three fungi. The associations which include A. robusta were less efficient in this study than D. flagrans alone or associated with M. thaumasium.