Bran Mash: What's it Really Good For?

During the colder months, many horse owners go on a quest for wheat bran, probably so that they can make their four-legged friends a bran mash--a warm treat for horses on frosty winter days. Aside from the obvious, what's in a bran mash? And what is it meant to do?.

Here's an easy recipe. The two basic ingredients, simply enough, are wheat bran (rice bran, which is relatively high in unsaturated fats and is often used as a fat supplement in the diet of high-performance horses) and boiling water. The amount of water used depends on the desired wetness or sloppiness of the mash. Blend thoroughly and steep for at least 15 minutes, covering the bucket or feed tub with a towel. Just prior to feeding, add any other ingredients that might tempt a horse to dive in, such as diced apples, sliced carrots, a pull of molasses, or a handful of oats. And voilà ... a bran mash is created.

Bran mashes remain a staple in the feeding regime of some horsemen and continue to be a traditional meal for horses recovering from sickness, for mares immediately following foaling, and for aged horses with dental problems. A bran mash also is often the meal of choice for horses following an intense workout, especially for those that do not drink adequately during or after intense exercise and teeter on the brink of dehydration.

However, aside from the B vitamins niacin, thiamin, and riboflavin, wheat bran offers little in the way of nutrition. Even as a fiber supplement, wheat bran contains only 10-12% crude fiber, which is considerably less than other sources of fiber such as beet pulp (20%) or grass hay (28-34%).

In terms of macromineral balance, bran mashes can be problematic. While no cereal grain or grain byproduct contains an equal ratio of calcium to phosphorus, wheat bran contains an exorbitant amount of phosphorus. If fed often enough, the imbalance in wheat bran can lead to skeletal problems, particularly in young horses, but the occasional bran mash will not upset body-wide mineral levels. Avoid feeding bran mashes to young horses, and do not allow mashes to constitute more than 10% of the daily ration of an adult horse.

In recent years bran's long-standing laxative properties have been under fire. For decades, horsemen have believed that bran might prevent colic in horses by keeping ingesta (ingested feed) flowing smoothly through the digestive system. Research, however, suggests otherwise. In fact, a study conducted at Cornell University completely denounced this tightly held belief. Fed wet or dry, wheat bran was found to have no notable effect on the moisture content of stool. Even when fed in its most sloppy state, fecal water content only increased 3%.

So how do researchers explain the loose manure that many horses offer up the day after a bran mash is given? Researchers believe it stems from subsequent, though mild, digestive upset caused by the sudden change in diet. Some scientists feel that bran mashes might even have a negative effect on the gastrointestinal tract's resident population of fiber-fermenting microbes.

Contrary to popular belief, a bran mash will not warm a horse in the bitter cold. That job is most effectively achieved by meting out appropriate amounts of forages, as more body heat is generated through the digestion of hay and other roughages than any grain or grain byproduct.

While some research puts the lore and lure of bran mash on shaky ground, periodic feeding might still have its place in some horses' diets. A finicky eater might not be able to resist the temptation of a warm bran mash, and there simply might not be a better way to disguise medications than to diffuse their bitterness in the pleasantness of a bran mash. If medications are added to the mash, sprinkle them in just prior to feeding because cooking could alter their effectiveness.

Article reprinted with the permission of copyright holder Kentucky Equine Research (KER). Visit for more horse health and nutrition information.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More