León González, Jorge AlexanderPérez Anzúrez, GustavoAbreu Ramos, InêsMagos Amado, Carlos EmilianoBoso Dafonte, DavidLozano, JoãoHernández Malagón, José ÁngelCazapal Monteiro, Cristiana FilipaBonilla, RodrigoSanchís, JaimePaz Silva, AdolfoSánchez-Andrade Fernández, RitaCarvalho, Luis Manuel Madeira deArias Vázquez, María Sol2025-12-022025-12-022025-11-15León, J.A.; Pérez-Anzúrez, G.; Ramos, I.A.; Magos Amado, C.E.; Boso Dafonte, D.; Lozano, J.; Hernández Malagón, J.Á.; Cazapal-Monteiro, C.; Bonilla, R.; Sanchís, J.; et al. Testing a Sustainable Strategy Against Poultry Helminth Stages Developing in the Soil. Pathogens 2025, 14, 1168. https://doi.org/10.3390/pathogens14111168https://hdl.handle.net/10347/44173Free-ranging hens are at risk of infection by parasites characterized by certain stages that develop in the soil until attaining the infective phase. To analyze the usefulness of a biological control strategy of helminths affecting pasturing hens, fecal samples containing eggs of the helminths Ascaridia galli and Capillaria spp. were collected and then homogenized with an electric mixer. A total of 64 small areas were established by placing wooden frames (15 × 40 × 30 cm) on the ground and then adding approximately 100 g of a fecal mixture (per area). Four batches of 16 areas were considered: G1, sprayed with 2 × 106 spores of the parasitophagous fungus Mucor circinelloides (day 0) at 0.5 L/m2 (=600 mL/area); G2, sprayed with spores twice (every two weeks); G3, sprayed four times (every week); and Control, sprayed weekly with water. After a four-week period, the egg viability reduced for ascarids and capillarids (26% and 27%, respectively) in the control group; 64% and 79% in G1; 71% and 82% in G2; and 79% and 80% in G3. It was concluded that spraying with fungal spores provides a very useful tool for preventing infection by helminths on free-range poultry.eng© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) licenseAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/PreventionParasitesBirdsFree-rangeParasitophagous fungiSprayingjournal article10.3390/pathogens141111682076-0817open access