Analysis of current equine feeding practices in the Netherlands and identification of potential nutrient leaching and environmental contamination factors.
Authors: Karasu Gulsah Kaya, Rogers Chris W
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Dutch horse owners are routinely overfeeding their animals, with 90% providing excessive metabolisable energy and most offering concentrate feeds alongside hay despite limited pasture access—a practice that generates substantial nutrient excretion with environmental implications. Researchers surveyed 274 horse owners, capturing detailed feeding records and animal demographics (mean bodyweight 542 kg, predominantly adult warmbloods with restricted grazing of less than 10 hours daily), then modelled dietary nutrient intake against NRC recommendations and calculated resulting faecal excretion rates. The findings revealed concerning levels of dietary excess: starch averaged 2.4 g/kg bodyweight and sugar 1.4 g/kg bodyweight well above requirements, whilst nitrogen excretion reached 228 g per horse daily (equivalent to 8.47 kg per tonne of manure), with faecal micromineral losses substantial and largely unnecessary—particularly copper (141 mg/day), zinc (593 mg/day) and manganese (957 mg/day). For equine professionals involved in nutrition planning and herd health, these results highlight both an immediate welfare concern (excess dietary energy predisposes to metabolic disease, particularly in leisure horses with minimal work) and an underappreciated environmental burden, as overfed horses represent a significant source of nutrient pollution through manure management, making dietary optimisation not merely an efficiency matter but an essential element of responsible horsemanship.
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Practical Takeaways
- •Review concentrate and supplement protocols against NRC guidelines to reduce excess nutrient intake, which will lower manure nitrogen and mineral content and reduce environmental impact
- •Educate horse owners that most horses in pasture-based systems are receiving more energy, starch, and minerals than required, representing both unnecessary expense and environmental liability
- •Consider implementing farm-level nutrient management plans to account for elevated mineral excretion when disposing of manure or using it for land application
Key Findings
- •85% of surveyed horses had access to less than 200 m² of pasture with median grazing time of 10 hours daily
- •93.8% of horses received concentrate feeds and 80% received dietary supplements, with 90% receiving excess metabolizable energy compared to NRC recommendations
- •Mean daily nitrogen excretion was 228 ± 134 g per horse (8.47 kg per ton of manure), with excessive fecal excretion of copper (141.0 ± 151.3 mg), zinc (593.1 ± 504.4 mg), manganese (957 ± 541.2 mg), and cobalt (2.3 ± 3.5 mg)
- •Current equine feeding practices in the Netherlands present significant potential for nutrient leaching and environmental contamination through excess mineral and energy supplementation