Impact of Year-Round Grazing by Horses on Pasture Nutrient Dynamics and the Correlation with Pasture Nutrient Content and Fecal Nutrient Composition.
Authors: Ringmark Sara, Skarin Anna, Jansson Anna
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Year-round grazing by horses produces markedly different pasture dynamics compared to conventional mowing regimes, with significant implications for both forage quality and herd nutritional status. Swedish researchers monitored twelve Gotlandsruss stallions grazing three enclosures at low density (0.35 horse/ha) over two years alongside mown control areas, collecting monthly pasture samples and fecal material to assess nutrient composition and intake. Whilst unmown exclosures showed declining energy and crude protein content over the study period, grazed areas maintained and increased their nutritive value—suggesting that selective grazing creates heterogeneous swards with superior nutritional profiles compared to uniform mown pastures. Fecal analysis revealed moderate to strong correlations between faecal and pasture nutrients (r = 0.3–0.8), providing practitioners with a practical non-invasive tool to assess dietary quality on grazing operations. These findings challenge the assumption that mowing alone optimises pasture nutrition; for equine operations pursuing year-round grazing models, this evidence supports the nutritional viability of extensive systems whilst highlighting that grazing-induced pasture diversity may reduce supplementary feeding requirements and benefit long-term sward health.
Read the full abstract on PubMed
Practical Takeaways
- •Year-round grazing by horses can maintain or improve pasture nutritive value compared to mechanical mowing alone, potentially reducing supplementary feeding needs in certain management systems
- •Fecal nutrient analysis can serve as a practical indicator of pasture quality and nutritional availability for grazing horses
- •Rotational grazing systems at moderate stocking density (~0.35 horses/ha) may provide better biodiversity and pasture health outcomes than uniform mowing schedules
Key Findings
- •Year-round horse grazing at 0.35 horses/ha increased pasture energy and crude protein content over three summers, whereas monthly mowing decreased these nutrients
- •Grazed areas showed greater final biomass content per hectare compared to mown exclosures
- •Fecal organic matter and crude protein content demonstrated moderate to strong correlations with pasture nutrient content (r = 0.3–0.8)
- •Horse grazing diversified pasture chemical composition compared to the uniform effects of monthly mowing