How to Feed Horses: General Guidelines

Horse owners ask many questions of equine nutritionists about how to best nourish a horse to support its lifestyle, age, and performance, among other factors. While meeting nutritional needs is a primary goal, a secondary objective is to ensure that feeding management supports gastrointestinal tract health, since the horse’s digestive system is prone to disturbances resulting in colic, laminitis, and other concerns.

The following guidelines provide a solid foundation for the nutritional management of horses.

Feed according to body weight. The total daily intake of a horse depends on body weight. Typical feeding recommendations include 1.5-2.5% of body weight in forage and then a percentage of body weight of feed or ration balancer to provide additional nutrients not provided by forages. To determine body weight, one can use a livestock scale, a weight tape, or an equation. This is a useful equation: body weight (lb) = heart-girth (in) x heart-girth (in) x body length (in) divided by 330. Once the horse’s body weight is determined, the appropriate amount of forage and additional fortification can be calculated, and then this can be adjusted as needed to meet the horse’s requirements.

Measure ration components by weight, not volume. A scoop is not an accurate measurement of feed, nor is a flake an appropriate measure of hay. Every scoop or flake likely weighs a different amount, so it is important to weigh the scoop of feed and the amount of hay to accurately determine a horse’s daily ration. A digital fish or luggage scale is an easy tool to use to weigh feed and hay to ensure the horse is receiving the correct amounts for each meal.

Body condition scoring. A good understanding of body condition scoring is helpful for horse owners to objectively determine if a horse is overweight, underweight, or just right. Overweight and underweight horses are at increased risk of developing health problems, so it is helpful to recognize and correct calorie intake to support an appropriate body condition. Discover a myriad of body condition resources.

Do not overfeed nonstructural carbohydrates (NSC). The architecture of the horse’s digestive tract is designed for NSC (dietary starch and sugars) to be primarily digested and absorbed as simple sugars in the small intestine. If dietary NSC exceeds the absorption capability of the small intestine, especially if the excess is not customary for the horse, the NSC can pass into the microbial environment of the hindgut and disrupt the microbiota, increasing the risk of digestive disturbance. A general rule of thumb is to feed no more than 0.5% of the horse’s body weight in high-NSC feed (such as cereal grains) per meal (or no more than 5 lb [2.3 kg] of grain per meal for a 1,000-lb [450-kg) horse). If the feed is lower in NSC, the amount per meal may be increased. Some horses are sensitive to dietary NSC due to health conditions such as myopathies, gastric ulcers, or insulin dysregulation, so dietary NSC recommendations may be more restricted.

Supplement with care. Commercial horse feeds are designed with precise, optimal nutrient balances to meet the requirements of the various classes of horses. Some horse owners then dilute or “cut” these balanced feeds with a cereal grain (often oats) or other feed ingredient, thereby changing the total nutrient balance and potentially decreasing the feed’s nutritional value for horses. Further, supplementation of individual nutrients such as minerals or some vitamins can result in serious nutritional imbalances and possibly nutrient toxicities. Working with an equine nutritionist can be beneficial in evaluating a horse’s total ration to ensure nutrient requirements are met without imbalances or excesses.

Forage is the base of equine diets. Horses require at least 1-1.5% of their body weight per day of roughage in their diets, and many nutritionists recommend 1.5-2% body weight per day in forage. Feeding adequate amounts of high-quality forage can prevent many digestive disturbances as well as behavioral problems. For horses that require restricted forage due to a medical condition or to reduce calorie intake from forage, using tools such as grazing muzzles or slow-intake haynets or feeders can support gastrointestinal tract health while restricting forage intake.

Feed and forage quality. Avoid dust and mold and keep the feed bucket, tub, or manger clean. The gastrointestinal tract is not equipped to deal with dust or mold, so poor-quality hay or grain will not be digested efficiently and may cause health problems for the horse. Further, inhaling respirable antigens often present in hays and dry feeds can cause or exacerbate respiratory conditions such as equine asthma.

Consistent feeding schedules. Horses thrive in consistent environments, and those that are fed on fairly consistent schedules may be less likely to go off their feed or develop undesirable stall habits. Horses fed on inconsistent schedules may get hungry and bolt their feed, possibly resulting in choke or digestive disorders. Further, spacing meals evenly throughout the day helps ensure more efficient digestion and absorption in the gastrointestinal tract.

Changes in feed or forage. Abrupt changes in feed or hay increase the risk of digestive upsets such as colic in horses. Changes in feed should be made gradually—a small change can be spread over four to seven days, while a radical change may take up to three weeks. Horse owners often do not consider making forage changes gradually, but sudden changes in hay or switching between hay and fresh pasture also increases the risk of digestive disturbances. Such changes should also be made gradually to allow the horse’s gastrointestinal tract and microbiota to acclimate to the new diet.

Feeding in a group setting. If horses live in a group setting and must be fed together, individual feeders should be available and spread far apart. To help ensure that all horses have the chance to eat a full meal, put out extra feeders and make provisions for timid horses that are low in the pecking order. However, the only way to make sure that each horse meets its nutritional requirements is to feed separately.

Provide clean, fresh water. Horses should have access to clean, fresh water. Hot, sweaty horses should receive water immediately after exercise, but possibly only a few swallows at a time as the horse cools. During temperature extremes, water intake may be affected as horses usually do not prefer excessively warm or cold water. In winter, snow cannot take the place of water, and heaters in buckets or water troughs can help encourage adequate water intake.

Regular exercise. Daily exercise helps maintain regular eating habits, desirable stall behavior, and general health.

Dental care. Horses require routine dental care. The grinding motion of chewing can result in sharp points on the teeth, which can cause pain, reduce the efficacy of chewing, and may also affect performance. A veterinarian can smooth the grinding surfaces of the teeth and help ensure that horses can most efficiently chew their feed and forages.

Parasite control. Parasites can increase the risk of digestive tract problems, such as colic or ulcers. Horse owners should practice parasite-control measures including an appropriate deworming schedule for individual horses (as advised by a veterinarian based on fecal egg tests), harrowing and rotating pastures, and proper manure disposal.

Monitor changes in feces. Horse owners should be aware of changes in amount, consistency, color, odor, and composition of feces. Changes in a horse’s manure may be an early indication of a digestive disorder.

Routine veterinary care. A horse must be in good health to get the most out of its nutrition program. Routine vaccinations, dental care, and deworming are essential components of an optimal wellness program for the horse.