Why You Shouldn't Feed Bran Mashes to Horses

During the cold fall and winter nights, owners may feel the urge to warm up some hot water and mix it in with some bran to make a nice, warm mash for their horses. Once thought of as a nice treat for horses, we now know that bran mash may not be a safe or suitable food choice. Advancements in equine nutrition and research studies are showing that bran can be a poor food choice, even as a treat, for any type of horse.

Why People Feed Bran Mash to Horses

Bran is the outer covering of cereal grains. In the past, it was widely available around mills that processed grains and was a feed alternative used by some horse owners. This is because it was highly available, most likely cheaper than other grains, and was thought to be a decent horse feed.

Today, wheat bran is the grain of choice for some horse owners and is usually given as a treat or feed additive, rather than as a concentrated meal. The typical situation people may give their horses bran in a mash may be:

  • During cold nights, believing it will help warm them.
  • During times of stress or after exercise as a “nutritious” treat.
  • As a laxative to help digestion and maintain a healthy digestive tract.
  • To help encourage drinking or to increase moisture in the diet.

There are many suggested alternatives that are better for your horses, which include:

  • Feeding more forage during cold nights is a better option to helping horses to stay warm. As highlighted in our Caring for Your Horse This Winter article, feeding more forage leads to higher body temperatures due to fermentation of fiber in the horse’s gut.
  • A good alternative to help horses during times of stress is feeding pre- and probiotics to maintain gut health. There are many products on the market, including Constant Comfort® or Advance Paste®.
  • A nice alternative to a bran mash is to simply add hot water to your horse’s feed and make a mash of that, rather than introducing a new feedstuff, like bran.
  • There are better options to get a horse to drink water. In our Tips for Encouraging Horses to Drink Water article, we highlight that water can be flavored, warmed or added to a horse’s normal, everyday feed.

What Is the Nutritional Value of Bran for Horses?

Because bran is a grain by-product left over from the processing of cereal grains, its nutritional value is minimal, at best. The most concerning aspect of feeding bran is the high phosphorus to calcium ratio. As a reminder, a horse’s diet should consist of 2-parts calcium to 1-part phosphorus. With wheat bran, that ratio is reversed at a 1-part calcium up to 11-parts phosphorus. Other nutritional aspects of wheat bran include:

  • Higher in fiber than other grains, but majority is indigestible for horses.
  • Higher protein at 17% compared to other cereal grains, but not a quality protein and isn’t digested as well.
  • Some B-vitamins, but devoid of others, such as vitamin A, D, or E.
  • Minimal fatty acids, but is higher in the omega-6 as compared to omega-3 fatty acids.
  • High in non-structural carbohydrates, ranging from 26% to 30% NSC.

All-in-all, there are no advantages of feeding horses a bran mash as compared to other feed alternatives. The nutrients provided by bran do not justify its use and, in fact, represents more of a danger to horses.

The Dangers of Feeding Bran to Horses

As previously mentioned, a major concern with feeding a bran mash is the high phosphorus to calcium ratio. In the past, horses that were fed wheat bran mash regularly suffered from hormonal imbalances (hyperparathyroidism). This resulted in an enlargement of the horse’s facial bones and the weaking of the other bones in the body. This also became known as bran disease, big head disease, or miller’s disease. The horse, in essence, is leaching calcium from its bones due to this huge imbalance of calcium and phosphorus, which also leads to abnormal growth of facial bones.

The other major concern with occasionally feeding bran mash is the sudden introduction of a high NSC feedstuff or change in diet. The reports that bran mash acts as a laxative is most likely caused by a disruption to the gut bacteria, resulting in diarrhea. There is also a danger of putting your horse at risk of colic or laminitis. Additionally, the high NSC content of bran can be an issue to horses that are suffering from metabolic disorders. Horses suffering from metabolic issues need to be carefully managed and fed low NSC diets, which includes treats, like an occasional bran mash.

Take Home Message

Overall, there are no real benefits to feeding your horse a bran mash. In fact, it can be detrimental to their overall health and well-being. The notion of providing a comfort food to a horse does not justify the risks of feeding bran mash. If you have any questions or need advice on alternatives to feeding bran mash, please feel free to contact us for a free, personalized feeding plan!


National Research Council. (2007). Nutrient requirement of horses, 6th rev. ed. National Academies Press.

Article By: Chris Mortensen, Ph.D.
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