Horse Feeding Management Guidelines

By Katie Young, Ph.D., Consulting Equine Nutritionist, Purina® Mills, LLC

Feeding horses correctly and safely often seems complicated because they are unique in the livestock world and cannot be fed the same way as cattle, hogs, sheep or other livestock species. However, following a few horse feeding guidelines when feeding horses will go a long way toward ensuring your horse's nutrient requirements are met without increasing the risk of digestive disturbances that seem to plague many horses.

Feed horses according to lifestyle.
Horses require different amounts of nutrients according to their lifestyle. When feeding horses, owners must ensure that each horse receives a total diet that meets its specific needs.

How much feed?
To be sure that you are feeding horses the correct amount, horse owners must know the horse's body weight. To determine body weight, one can use a livestock scale, a weight tape (available from your Purina® dealer) or the following equation:

BW (lbs) = (Heart girth x Heart girth x Body length) divided by 330.

(Heart girth is measured as the circumference over the withers and around the barrel. Body length is measured from the point of the shoulder to the point of the buttocks. All measurements should be recorded in inches.)

Once body weight is determined, use the guidelines on feed bags or our feeding calculator (available at to calculate feed and hay needs.

Measure feed by weight, not volume.
A 3-pound coffee can of oats is not the same amount of feed as a 3-pound coffee can of corn! The can may hold 3 to 4 pounds of oats, while the same can may hold 4 to 5 pounds of corn. And since corn is more calorie-rich than oats, that can of corn may contain 2 to 3 times the energy as the can of oats. Any time a horse owner changes feed, he or she must weigh the can of feed to ensure the horse receives the same amount every meal.  Another option for measuring feed is to use a premeasured scoop.

Do not overfeed grain.
Horses have very small stomachs in relation to their total size, so feeding too much grain in one meal can overload the stomach and cause problems such as colic or laminitis. A general rule of thumb is to feed no more than 0.5 percent of the horse's body weight in grain per meal, or no more than 5 pounds per meal for a 1,000 pound horse.

Do not dilute balanced rations.
Purina's® equine nutritionists formulate Purina® horse feeds with precise, correct nutrient balances to meet the requirements of the various classes of horses. Many horse owners then dilute or "cut" these balanced feeds with a cereal grain (usually oats), thereby changing the nutrient balance and decreasing the feed's nutritional value for horses.

Do not supplement balanced rations.
Purina® horse feed is already balanced to meet the horse's nutritional needs and contains sufficient amounts of all the necessary proteins, amino acids, vitamins and minerals. Because Purina® feed contains all the necessary nutrients for a horse's dietary needs, top-dressing the ration with a protein, vitamin or mineral supplement is not necessary. And this may cause nutrient imbalances and possibly toxicities.

Feed adequate roughage.
Horses require at least 1 to 1.5 percent of their body weight per day of roughage in their diets. Feeding adequate amounts of high-quality roughage can prevent many digestive disturbances as well as behavior problems.

Use only top-quality feeds.
Avoid dust and mold, and keep the feed manger clean. Dust and mold can cause severe respiratory and digestive problems for horses. The grains used in Purina® Horse Feeds must pass stringent quality tests, thereby ensuring only clean, high-quality ingredients in each bag.

Feed at the same time every day.
Horses that are fed on a consistent schedule are less likely to go off feed or develop undesirable stall habits. Inconsistent feeding schedules lead to hungry horses that may bolt their feed, possibly resulting in choke. Spacing meals evenly throughout the day is healthier for the equine digestive tract.

Avoid sudden changes.
Consistency is another important factor in reducing the chance of digestive upsets in a horse. Changes in types of feed should be made gradually (4 to 7 days for small changes; up to three weeks for radical changes).

Provide clean, fresh water.
Horses should have access to clean, fresh water at all times.  After hard workouts, horses should receive plenty of water, but only a few swallows at a time until they are cooled.

Routine veterinary visits.
In order for a horse to get the most out of its nutrition program, it must be in good health. Regular vaccinations, dental care and deworming measures are essential to overall wellness.