Comparing the effects of horse grazing alone or with cattle on horse parasitism and vegetation use in a mesophile pasture
Authors: Fleurance Géraldine, Sallé Guillaume, Lansade Léa, Wimel Laurence, Dumont Bertrand
Journal: Grass and Forage Science
Summary
# Mixed grazing with cattle shows promise for reducing horse parasitism but requires thoughtful management Mixing horses and cattle on pasture is often promoted as a way to improve vegetation use and lower parasite burdens through dietary complementarity and the "dilution effect," yet evidence supporting these assumptions remains limited. Researchers in central France grazed horses alone or with cattle at equivalent stocking rates (1.4 livestock units/hectare) on two alternating plots with 15–21 day rotation intervals, monitoring foraging behaviour, sward structure and gastrointestinal nematode (cyathostome) infection in the horses over the grazing season. Horses preferentially selected short (≤4 cm) and intermediate (5–8 cm) high-quality regrowth whilst avoiding faecal-contaminated areas, whilst cattle—constrained by their bite mechanics—targeted intermediate and tall vegetative patches; critically, cattle's selective avoidance of short swards where infective cyathostome larvae concentrate near horse dung appeared to limit their larval intake and may reduce reinfection pressure on horses in mixed groups. Importantly, however, co-grazing did not enhance overall sward heterogeneity or herbage quality compared with horse monoculture, suggesting that the complementary feeding patterns alone did not optimise vegetation management. For practitioners considering mixed grazing systems, the findings indicate potential parasite-control benefits—particularly if cattle exposure to contaminated short patches can be minimised—but emphasise that rotation length, stocking rate and paddock layout must be deliberately designed to leverage dietary differences rather than assumed as automatic advantages of multi-species grazing.
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Practical Takeaways
- •Mixed horse-cattle grazing can work behaviorally (minimal conflict), but don't assume it automatically reduces parasite burden—cattle still graze contaminated areas due to their height constraints
- •Horses' natural latrine behavior and selection of short regrowth means they concentrate parasites in specific patches; cattle grazing these same patches may still expose them to infective larvae despite spatial separation benefits
- •Manage mixed grazing actively with appropriate rotation (15-21 days) and stocking density (1.4 LU/ha) to maintain complementary feeding patterns—it's not a 'set and forget' solution for parasite reduction
Key Findings
- •Horses and cattle acclimated quickly with minimal agonistic interactions in mixed grazing systems
- •Horses selected short (≤4 cm) and intermediate (5-8 cm) high-quality regrowth while avoiding fecal-contaminated areas due to latrine behavior
- •Cattle avoided short patches contaminated with horse dung, potentially reducing their exposure to infective cyathostome larvae concentrated near feces
- •Mixed grazing did not reduce sward structural heterogeneity or enhance overall herbage quality compared to horse monoculture