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, <i>Duddingtonia flagrans</i>, <i>Monacrosporium thaumasium</i>, and <i>Arthrobotrys robusta</i>, in the biological control of cattle gastrointestinal nematodiasis in comparison with the use of the fungus <i>D. flagrans</i> alone. Five groups consisting of eight Girolando heifers were kept in paddocks of <i>Brachiaria decumbens</i> 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 <i>D. flagrans</i> and <i>M. thaumasium</i> in coadministration, G2 received <i>D. flagrans</i> and <i>A. robusta</i>, G3 received <i>M. thaumasium</i>, <i>A. robusta</i>, and <i>D. flagrans</i>, and G4 received the fungus <i>D. flagrans</i> 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 <i>D. flagrans</i> or <i>D. flagrans</i> + <i>M. thaumasium</i> produced significantly better results than the <i>D. flagrans</i> + <i>A. robusta</i> or the combination of the three fungi. The associations which include <i>A. robusta</i> were less efficient in this study than <i>D. flagrans</i> alone or associated with <i>M. thaumasium.</i>