Bran Mash: A Mashup of Myths

Courtesy of Kentucky Equine Research

On cold winter days, a hot beverage helps fight off chills. Many people like to do the same for their horses, often in the form of a warm bran mash. A common belief is that it will help warm the horse and have a laxative effect. However, neither is true! 

Although bran mashes often make people feel like they’ve done something good for their horse, there is no proven nutritional benefit.

Bran is the outer layer of grain that is removed during milling. Wheat bran is light and low-density, and it contains the B-vitamins folate, niacin, thiamin and riboflavin. 

However, bran is fairly low in fiber, containing roughly only 10-12% crude fiber. 

Contrary to popular belief, bran does not have a laxative effect on horses. Studies have shown no increase in fecal water content after ingestion of bran mashes. In fact, feedstuffs like beet pulp or soy hulls have much higher digestible fiber than wheat bran. If bran mashes are fed inconsistently (once per week or only when the temperature is very cold), the result may be digestive upset if it is not a regular part of the horse’s diet.

“Wheat bran is high in phosphorus and low in calcium, a situation that nutritionists refer to as a reversed calcium-to-phosphorus ratio,” says Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research.

Horses require more calcium than phosphorus (1.5-2 parts calcium to 1 part phosphorus for mature, adult horses). When this ratio is reversed and not corrected, it can cause developmental orthopedic disease in growing animals, and nutritional secondary hyperparathyroidism (NSH), a metabolic bone disease, in growing or adult horses. Bran is not harmful if total dietary phosphorus is not excessive and if the diet is balanced to include an appropriate amount of calcium.

Knowing this, you may wonder if it is ever acceptable to feed a bran mash. The answer is yes, but it should be done the correct way. Bran mashes have benefits, such as helping to get some water into the horse, disguising medication, and adding energy to the diet. Bran has a similar energy content to oats and is typically slightly higher in protein concentration. However, because bran can have up to four times the amount of phosphorus compared to other grains, the diet must be balanced for calcium, and total dietary phosphorus must be kept in check. Alfalfa and beet pulp are good sources of calcium.

In summary, if used, a bran mash should be consistently offered to horses so they are appropriately acclimated to it. Avoid intermittent feeding of any feedstuff the horse is not used to in order to reduce the risk of digestive upset. A qualified nutritionist can evaluate a horse’s diet to ensure a proper calcium-to-phosphorus ratio is fed. Finally, remember that the best way to help your horse stay warm is by increasing forage (and water) and providing shelter during a cold snap.