Viabilidade dos fungos predadores Monacrosporium thaumasium e Duddingtonia flagrans e da moxidectina sobre nematoides gastrintestinais de bovinos de corte

• Autor(a) principal: Assis, Rafaela Carolina Lopes
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1461
• topic: Controle biológico; Helmintos; Fungos nematófagos; Biological control; Helminths; Nematophagous fungi; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Sodium alginate pellets of two different nematode predatory fungus D. flagrans and Monacrosporium thaumasium (biologic control) and Moxidectin (chemical control) were evaluated in the control of bulls gastrointestinal nematodiasis. Four groups of ten six month-old male Nellore calves were kept in paddocks of Brachiaria decumbens for 12 months. Each animal of group A received 1g/10 kg of body weight (b.w.) of pellets of D. flagrans (0.2 g of fungus/10 kg b.w.) twice a week, for 12 months. In group B, each animal received 1g/10 Kg of body weight of M. thaumasium pellets, twice a week, for 12 months. In group C each animal received 1 mL/50 Kg body weight of the anthelmintic moxidectin 1% in May, July and September 2010. Animals of the group control (group D) received no treatment. In the analysis of fecal egg count (EPG) of groups A and B were 56.7% and 47.8% smaller than control group (p<0.05). The Moxidectin reduced by 93.8% in the first six months of the study (period of application) and 12.4% in the last six months, indicating re-infection by nematodes. The biologic control maintains a low EPG in long-term while chemical control results in a short-term effect. The percentage reduction of L3 in relation to the group control in the distances of up to 20 and 20-40 cm from the fecal pat was 64.5% and 73%, respectively, for group A, group B showed percentage reductions of 47.3% and 58%, in the same distances. The fungal isolate of D. flagrans (AC001) showed greater reduction of EPG and L3 on pasture when compared to M. thaumasium. Treatment of bulls with pellets containing the nematophagous fungus and moxidectin can be used integrated as an alternative treatment of bovine gastrointestinal nematodiasis; however, biologic was more efficient than chemical control for a long-term and allows improvement in weight gain of calves, an essential factor for beef cattle.