Neglected, non-productive pastures can result in poor health and body condition of horses, and may also be a major source of exposure to internal parasites such as large and small strongyles and ascarids. Horses on pasture must be maintained on a parasite control program and checked frequently for injuries from unexpected encounters with fences, other horses, and miscellaneous environmental hazards. Pastures should be frequently inspected for dangerous objects and possible toxic plants. Pastures located near wooded areas may contain white snake root, or bracken fern, while horses in pastures bordering residential areas may occasionally be exposed to poisonous ornamental plants such as Japanese Yew or cherry trees. Undesirable broadleaf weeds can be controlled with a herbicide such as 2,4-D, but horses should not graze treated pasture for at least 7 days after application.
Horses are selective grazers, which affects the productivity of a pasture.
Horses prefer to eat young, immature plants and will graze some areas of a pasture down to the bare ground. In other parts of the pasture, they will allow the plants to grow to maturity, which lessens palatability and nutrient availability. This grazing pattern is often called spot or pattern grazing. Horses will not graze in areas where they defecate. Establishing the Pasture Soil testing is the first step.