During these cold, dreary days of winter a common discussion around most barns and stables 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 devote this month’s column to the benefits and problems with the practice. 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 expensive for the nutritional value it provides.

Benefits

Bran mashes have traditionally been provided to horses by their owners because they believe the high fiber content of 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. 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 resultant 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 of them 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”. 

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

Concerns

Nutritionist point out several potential problems with feeding bran mash too often. Horses require a higher calcium than phosphorous ratio 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 know as Nutritional Secondary Hyperparathyroidism, more commonly know as Big Head. This condition used to be called Miller’s Disease because it was common in horses own by grain millers who provided their horses the bran by-product of wheat milling. The disease is characterized by enlargement of the facial bones and weakening of all other bones in the body. To prevent this condition, by correcting the calcium/phosphorous ration, some horse owners mix alfalfa cubes into their bran mash. Another concern expressed by some nutritionist 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. 

Conclusion

The bottom line is that a bran mash provided no more often than once a week is a good treat for your horse and may provide some benefit to the animal’s intestinal tract, but daily supplementation should be avoided. If you have questions regarding bran mashes, talk to your local equine extension nutritionist or veterinarian. 

About the author: Thomas R. Lenz, DVM, MS, DACT, is a trustee of the American Horse Council, past chairman of AQHA’s research committee and past president of the AAEP.

Reviewed and updated by original author in 2016.