Horses should be fed a mainly forage diet and only adding in grain as needed. In almost all cases, horses should have access to fiber at all times. For overweight horses, this may mean including low quality hay or straw mixed in with better quality hay. Consistent access to hay acts as an ulcer preventative, satisfies their chewing need, and aids the horse in digesting food in the hindgut.
Free choice hay refers to a feeding system where horses and other equines have access to hay at all times rather than being fed hay at specific meal times. In a free choice hay system, the horse can eat as much or as little hay as they want, whenever they want.
Free choice hay provides a constant source of fiber, which is essential for maintaining digestive health and preventing ulcers and colic. In addition, having hay available at all times can help horses stay occupied and content, especially if they are stalled for long periods of time.
For overweight horses, extra precautions must be taken such as feeding a lower quality hay or even mixing in a feed-grade straw (such as oat or barley).