A combined effort to avoid strongyle infection in horses in an oceanic climate region: rotational grazing and parasiticidal fungi

José Ángel Hernández,Cristiana Filipa Cazapal-Monteiro,Jaime Manuel Sanchís,María Sol Arias,Fabián Leonardo Arroyo,Rita Sánchez-Andrade,Adolfo Paz-Silva

doi:10.1186/s13071-018-2827-3

José Ángel Hernández, Cristiana Filipa Cazapal-Monteiro + Show 5 more

Open Access

https://doi.org/10.1186/s13071-018-2827-3

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Abstract

BackgroundAn approach to preventing strongyle infection in horses was tested, comprising rotational pasturing and the administration of spores of two parasiticidal fungi, Mucor circinelloides and Duddingtonia flagrans.MethodsTwenty-two adult Spanish Sport Horses were dewormed with ivermectin (1 mg pour-on/kg body weight) and then randomly divided into three groups. G-1 was maintained with continuous grazing, and G-2 and G-3 were kept on a four-paddock rotation system. Commercial pelleted feed (2.5 kg/horse) was supplied to G-1 and G-2 twice a week; horses in G-3 received pellets containing 2 × 106 spores/kg of each fungus. Fecal samples were analyzed by the flotation method to estimate the reduction in the fecal egg counts (FECR), the percentage of horses shedding eggs (PHR), and the egg reappearance period (ERP).ResultsThird-stage larvae were identified in fecal pats as Cyathostomum (sensu lato) types A, C and D, Gyalocephalus capitatus, Triodontophorus serratus, Poteriosthomum spp., Strongylus vulgaris and S. edentatus. Two weeks after treatment, the FECR values were 100% in G-1, 96% in G-2 and 99% in G-3; the PHR values were 100% in G-1, 75% in G-2 and 88% in G-3. A strongyle ERP of 6 weeks was observed in G-1, ERP of 10 weeks was observed in G-2, and ERP of 16 weeks was observed in G-3. The counts of eggs per gram of feces (EPG) were > 300 EPG in G-1 and G-2 but remained below 250 EPG in G-3 throughout the observation period of 12 months.ConclusionsThese results suggest that horse strongyle infection could be decreased by combining rotational pasturing with feeding pellets containing the spores of parasiticidal fungi.

Highlights

An approach to preventing strongyle infection in horses was tested, comprising rotational pasturing and the administration of spores of two parasiticidal fungi, Mucor circinelloides and Duddingtonia flagrans
Rainfall peaked in January, and the lowest values were achieved in June; relative humidity higher than 81% was observed throughout the study
Fungal spores in the feces Spores of M. circinelloides and D. flagrans were first detected in all the G-3 horses two days after pellets were provided (Fig. 2)

Summary

Introduction

An approach to preventing strongyle infection in horses was tested, comprising rotational pasturing and the administration of spores of two parasiticidal fungi, Mucor circinelloides and Duddingtonia flagrans. Some strategies of biological control against strongyles include the utilization of soil saprophytic fungi such as Duddingtonia flagrans or Monacrosporium thaumassium [9], which are able to create traps in their mycelium where larvae are captured, immobilized and digested [10]. Administration of those spores has been advised as an appropriate procedure to prevent horse infection by strongyles [11, 12]. The possibility of enhancing the beneficial effect of rotational grazing by providing pelleted feed manufactured with the spores of M. circinelloides and D. flagrans has been evaluated

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