Biological control of gastrointestinal nematodes with the association of the nematophagous Duddingtonia flagrans and Pochonia chlamidosporia in horses kept at pasture

• Grant number: 21/03083-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2021
• Effective date (End): May 31, 2022
• Field of knowledge: Biological Sciences - Parasitology - Helminthology of Parasites
• Principal Investigator: Ricardo Velludo Gomes de Soutello
• Grantee: Sara da Costa Pinto
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

The objective of the study is to evaluate the action of the nematophagous fungus Duddingtonia flags as an alternative to biological control of helminthiases in naturally infected horses, kept on pasture. The experiment will begin in August 2021 to January 2022, using 30 female horses that will be distributed in 3 groups with 10 animals each, in an entirely randomized design (DIC). Abamectin will be administered orally 28 days before the beginning of the experiment in order to reduce and level the parasite load of all animals. In group 1, 1g of a formulation containing 1x105 chlamydospores of the fungus D. flagrans and 1x105 chlamydospores of the fungus P. chlamidosporia for each 10 kg of body weight will be provided, distributed in commercial feed. In group 2, the animals will be treated with the antiparasitic Ivermectin 1%, supplied as a paste orally at a dose of 0.2 mg/kg. In group 3, they did not receive any type of anti-helminthic treatment (control). The action of the treatments will be evaluated based on stool samples collected every 14 days and the results obtained from OPG examinations using McMaster chamber and the 'RESO' FECRT Analysis Program, version 2.0. Culturing and identification of infective larvae, the microbiology of the feces, and every 28 days, recovery and quantification of larvae in the pastures will be performed. Climatic data will be obtained from the Castilho, SP weather station. The means will be submitted to analysis of variance (ANOVA) using the Statistical Analysis System, version 9.2 (SAS Institute, Inc., Cary, NC, USA), and further analysis by the Tukey test (5%). (AU)