A new study has provided fresh insight into how much forage grazing horses consume, how efficiently they digest it, and how movement during foraging influences digestion.
The research, published in Scientific Reports, set out to tackle a long-standing challenge in equine nutrition: accurately measuring feed intake and digestibility in horses kept at pasture, where eating is closely linked to movement, selection and almost constant foraging activity.
Researchers monitored six horses kept on pasture around the clock, using naturally occurring plant markers (n-alkanes) alongside a synthetic marker to estimate organic matter intake and digestibility. To better understand how movement affects digestion, the horses’ daytime travelling distances were also tracked using GPS.
The study found that grazing horses consumed the equivalent of around 1.5 to 3.1 per cent of bodyweight per day in dry matter, with digestibility values ranging from moderate to high depending on the marker used. One plant marker in particular produced intake and digestibility estimates that closely matched existing literature, suggesting it may be especially useful for future pasture-based studies.
Horses showed wide variation in how far they travelled while grazing, covering anything from very short distances to several kilometres per hour. While movement varied significantly between days, it did not differ much within the course of a single day, reinforcing the idea that daily management and environment can strongly influence foraging behaviour.
Despite limitations linked to small sample size and the complexity of field measurements, the authors conclude that the combined use of intake markers and GPS tracking offers a promising approach to studying real-world grazing horses. They also highlight the importance of allowing horses as much freedom to forage and move as possible in modern husbandry systems, to meet both nutritional and behavioural needs.
🔗 Study details – Title: Feed intake, digestibility and passage kinetics in grazing horses. LINK https://doi.org/10.1038/s41598-026-35647-7
