Definition
To graze is to eat low-growing vegetation — primarily grasses and ground-level forbs — directly from the land surface. Horses are natural grazers; in the wild, they spend ten to seventeen hours per day in grazing movement, covering significant distances while taking small frequent bites. The behavior is not merely a feeding strategy but a digestive necessity: the equine stomach secretes acid continuously, and the buffering action of saliva produced during chewing is the primary mechanism that protects the stomach lining.
Grazing Behavior
When grazing, a horse uses its mobile lips and incisors to select and crop individual plants close to the ground. The highly flexible upper lip allows selective feeding, enabling horses to avoid unpalatable or toxic species under normal conditions. Movement during grazing is constant but slow, distributing intake across a pasture area. This natural spread prevents overgrazing of favored patches if the field carrying capacity is properly managed.
Why Continuous Grazing Access Matters
When horses are denied the opportunity to graze for extended periods — a common management pattern in stabled horses receiving only twice-daily feeding — gastric acid accumulates in the stomach without adequate buffering from saliva and swallowed forage. This is the main driver of continuous acid secretion ulcer development in stabled horses. Providing hay continuously, or extending pasture access, restores the buffering pattern. gut motility pain risk also increases when gastrointestinal motility slows during long periods without intake. Horses that graze or have constant forage access show lower incidence of both conditions.
Managing Grazing
Pasture management governs the quality and safety of what horses graze. Rotating fields prevents overgrazing and allows grass recovery. Testing for toxic plants, monitoring grass sugar content (which spikes in early spring and can trigger laminitis in susceptible horses), and maintaining appropriate stocking density are standard pasture safety practices. Spring grass, while highly palatable, can be dangerously high in non-structural carbohydrates for horses with metabolic conditions, making managed grazing — using grazing muzzles or restricting access time — a practical tool for at-risk animals.
Further reading: Grazing behavior on Wikipedia; Grazing at Britannica.