Horses are strongly motivated to forage (eating hay and grazing pasture) based on their inherent nature. In free-ranging horses, 70-80% of their time is spent eating. Pastured horses show a similar pattern to free-ranging horses. They will eat 10 to 12 hours daily in 30 to 180-minute bouts. The amount eaten during a grazing bout is related to the type and availability of forage, level of nutrient demand, satiety cues, taste and textures of the feed, and external cues. Free-ranging horses never fast for more than 3 to 4 hours.
Horses have mobile lips and large mouths. When grazing, the horse’s head is down, and the upper and lower incisor teeth bite several blades of grass, tearing off the grass close to the ground. The cheek teeth or molars grind the vegetation into smaller pieces before the horse swallows it. It will then take a step or two before repeating the process. Grazing occurs preferentially during hours of light, with peak activity occurring from dawn to midmorning and then again in the late afternoon and evening. Night grazing increases during the summer months. Domesticated pastured horses will exhibit the same feeding patterns.
Horses are selective and spot grazers. Horses select forages based on their maturity rather than botanical species. They prefer immature, leafy forages. Horses continually graze immature forages and leave more mature forage, which causes uneven growth throughout a pasture. Within a pasture, they will eat portions of a pasture down to the bare ground, while an area next to the bare spot may be lush and green. Thus, a feeding site can be easily overgrazed. Horses avoid grazing near feces resulting in the grass in elimination areas growing taller. When forages are sparse, a horse may eat other available forages and browse by chewing on wood, trees, tails, weeds, etc.
Horses are good at separating desirable and undesirable things from feeds. With grazing, a horse can shake the dirt from the roots of the grasses they pulled up. A horse can selectively choose the tasty part of hay and leave the stems and undesirable parts. Horses also separate medication from grains, even when owners take great measures to hide the taste. Olfaction is the primary sense used for avoidance of medications.
Horses without available pasture or free-choice forage should be fed at least twice daily to decrease the time between meals when a horse is without feed. If feeding concentrates, a good practice is to feed forage first. Feeding forage increases the time horses spend eating and results in slower digestion. Allowing large periods between meals may be linked to gastric ulcers and has been associated with an increased frequency of stereotypic behaviors.
Recommended Feeding Practices
- Employ feeding strategies that allow horses to forage (e.g., grazing pasture or eating hay in a dry lot). Self-exercise also stimulates gut motility.
- Allow horses to mimic their natural feeding behavior by implementing strategies to slow feed intake. Slowing forage intake can be accomplished by placing hay in multiple locations, using slow-feed hay nets and trickle feeders. Grazing muzzles can help slow pasture intake. Also, slow grain intake by spreading grain out in a shallow trough or placing large objects in a grain bucket (e.g., large, smooth rocks or bocce balls).
- Maximize the time horses have access to forage. Free-choice feeding of forage, feeding forage multiple times per day, or using slow feeding devices can increase the time horses have access to forage.
- Allow horses to feed in a head-down position when possible. This results in natural dental wear and reduces the risk of respiratory conditions.
Photo Credits: Adobe Stock