Soil fungi enable the control of gastrointestinal nematodes in wild bovidae captive in a zoological park: a 4-year trial

The control of gastrointestinal nematodes among ruminants maintained in zoological parks remains difficult due to infective stages develop in the soil. For the purpose to improve the possibilities of the control of gastrointestinal nematodes (genera Trichostrongylus, Nematodirus, Chabertia and Haemonchus) affecting wild captive bovidae ruminants belonging to the subfamilies Antilopinae, Caprinae, Bovinae and Reduncinae, commercial pelleted feed enriched with a blend of 104-105 spores of both filamentous fungi Mucor circinelloides + Duddingtonia flagrans per kg meal was provided for a period of 3.5 years. All animals were dewormed at the beginning of the trial and also when exceeding a cut-off point of 300 eggs per gram of feces (EPG). The anthelmintic efficacy ranged between 96 and 100%. The need for repeating the administration of parasiticide treatment disappeared at the 24th month of study in the Antilopinae individuals, and at the 8th month in the Caprinae, Bovinae and Reduncinae. No side-effects were observed on the skin or in the digestive, respiratory or reproductive system. It was concluded that this strategy provides a sustainable tool for preventing the contamination of paddocks where captive ruminants are maintained, decreasing the risk of infection by gastrointestinal nematodes and consequently the need of frequent deworming.