Why You Shouldn't Feed Bran Mashes to Horses

Some horse keeping traditions have withheld the test of time, for good reason. Others, like feeding the occasional bran mash, should be left in the past. Once thought of as a nice treat for horses, we now know that bran mash may is not a safe or suitable food choice.

What Is a Bran Mash?

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, bran from wheat is usually what is used in a bran mash. A bran mash is the mixture of bran with warm water and some with add other tasty additions like cut up apples or carrots. It is given as a treat or feed additive, rather than as a concentrated meal.

Why Do People Feed Brand Mash to Their Horses?

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.

Better Alternatives to Feeding a Bran Mash

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 Equi-Ferm XL®.

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?


Bran has limited nutritional value. 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.

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 weakening 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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