Bran Mash for Horses

Bran Mash for Horses

Is this warm bran mash beneficial to horse health? A veterinarian weighs the pros and cons.

horse eating from a bucket (Credit: Canva)

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By Dr. Thomas R. Lenz

During the cold, dreary days of winter, a common discussion around the barns in chilly areas of the world is whether or not horse owners should provide their horses with a bran mash daily, weekly or at all. So I thought it would be a good idea to discuss the benefits and problems of feeding bran.

What is Bran? 

Wheat bran is a fluffy, low-density feed that is similar in nutrient content to oats. It has one-half the density of whole oats, around one-fourth the density of corn or wheat and about four times the phosphorous content of most grains. It’s relatively high in vitamins such as niacin, thiamin and riboflavin, but much lower in B vitamins. It is somewhat palatable to horses, once they’ve become accustomed to it, but it’s expensive for the nutritional value it provides.

Bran Mash Recipe

There are a variety of bran mash recipes commonly used, and most involve mixing warm water with roughly four to eight cups of bran until the bran is well saturated. The mixture should cling together when you squeeze it. If you can squeeze water out of it, it’s too wet, and more bran should be added. Then any number of ingredients can be added.

Most horse owners add one tablespoon of salt (or electrolytes during hot weather).

Steamed oats, molasses, flaxseed, chopped carrots, sliced apples or a combination can also be added to increase the nutritional value of the mash or to make it more appealing to the horse.

Pelleted feeds are not routinely added, as they make the mash “mushy.”

Benefits of Bran Mash for Horses

Bran mashes have traditionally been provided to horses by their owners because they think the high-fiber content of the bran, combined with various mixtures of grains, supplements and warm water, increase water intake during cold weather and prevent colic. Or they simply want to give their horses a warm, comforting treat.

Many veterinarians recommend providing horses with a bran mash once a week during cold winter months when the horses might not be drinking enough water, following stressful work, during long trailer transport across the country or after foaling. They think providing a bran mash supplement stimulates the horse’s intestinal tract and provides an alternate water source.

Concerns When Feeding Bran Mash

Nutritionists point out several potential problems with feeding bran mash too often. Horses require more calcium than phosphorous in their feed, and wheat bran contains 10 times as much phosphorus as calcium.

As a result, horses fed bran daily, without correcting the mineral imbalance, can develop a metabolic condition known as nutritional secondary hyperthyroidism, more commonly known as “big head.” This condition used to be called miller’s disease because it was common in horses owned by grain millers who fed their horses the bran byproduct of milling wheat. The disease is characterized by enlargement of the facial bones and weakening of all other bones in the body.

To correct the calcium-phosphorus ration, some horse owners mix alfalfa cubes into their bran mash.

Another concern expressed by some nutritionists is that when an owner feeds a meal of bran mash, which can be a dramatic diet change, the original bacteria population that developed to digest the horse’s normal hay and grain diet is destroyed. Intestinal bacteria thrive in a steady, unchanging environment. Therefore, they recommend that if you’re going to feed your horse a wheat bran mash, the mash should be supplemented with digestive-aid products that help maintain healthy fermentation patterns in the horse’s intestinal tract.

Is Bran Mash Good for Horses? The Conclusion

The bottom line is that a bran mash provided no more than once a week is a good treat for your horse and can provide some benefit to the animal’s intestinal tract, but avoid feeding a mash daily. If you have questions regarding bran mashes, talk to your local equine Extension nutritionist or an American Association of Equine Practitioners veterinarian.

For a list of AAEP members, visit

Caring for Horses in Winter

From blanketing to feeding, hoof care to shelters, AQHA's free e-book, Caring for Horses in Winter, is a must-read for all horse owners. Download your copy today.