What is wheat Bran?

Bran is similar to other byproducts of the milling industry that found their way into livestock diets when manufacturers were searching for a profitable use for the byproducts.  When milling wheat the husk is removed before grinding the soft, inner kernel into flour. The husks are then turned into the large reddish-brown flakes known as Bran.

Horses, people discovered, liked the taste of Bran. And millers are more than delighted to sell Bran cheaply to those who want to feed it to their horses.

What is the Nutritional Value of Bran?

Bran 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 B vitamins such as niacin, thiamin and riboflavin, but much lower in other B vitamins.

Bran has an extremely lopsided calcium-to-phosphorous ratio of 1-to-12. The ideal ratio of calcium to phosphorous in a horse’s diet is 1-to-1 or 1-to-2.

Why Feed Bran to Horses?

There are many reasons people feed Bran.  Many feel that a hot Bran mash warms a horse in winter. Others feed it to get more water into the horse. Still others have told me they feed Bran for its laxative effects.

Personally I think there are better ways to warm your horse in the winter.  To me a better way to warm a horse in the winter is to increase the amount of hay it eats. Digestion of hay will raise the internal core temperature of your horse for hours.

As far as water intake, it will help, but a more long term way to get more water into the horse in the winter is to make sure water buckets stay thawed, water is an agreeable temperature or to add flavor or salt to the water to make it more palatable.

adamshorsesuppliesImage: Adams Horse Supplies

Still other horse owners feed Bran to “clean out the system”.  The more obvious reason some horses get looser stools with a weekly Bran mash has nothing to do with its laxative effect.  Rather, Bran loosens the manure of horses because if you feed it only occasionally it represents a sudden change in diet. 

As with most sudden changes in a horse’s diet, the gut microbes react and they start to die off. That causes the diarrhea or watery stool that horse owners erroneously assume is a laxative effect.  So substituting a Bran mash for the horse’s regular feed could cause a digestive upset and loose manure will result.  Therefore, this is less a way of “cleaning out his system” and is probably more a way to cause colic in your horse.

Arabian horse in the stable

Finally, some people feed Bran to help entice a horse to eat as they find it very palatable.  If you have a horse that is not a hardy eater (and there are a few), the taste of Bran is highly appealing to a horse so it could help picky eaters to clean up their feed.

What Are the Concerns with Feeding Bran?

As we have discussed, the possible intestinal reaction to an occasional Bran can make the weekly Bran mash a potential health risk. But the bigger danger of feeding Bran to horses is how it can affect the calcium-phosphorus ratio.

Bran is much higher in phosphorus than calcium, so long-term feeding of Bran without balancing the diet can result in mineral deficiencies.  If there’s not enough calcium to match the phosphorus in a Bran-fed horse’s daily feed, his body will pull extra calcium from his bones in order to balance the excess phosphorus in his gut.

You can feed alfalfa (hay, pelts or cubes) or other legume hays to balance out Bran’s phosphorous content.  If feeding grass hay you can add 2 ounces of feed-grade limestone to the horse’s daily grain ration.

Alfalfa cube

One final concern with feeding Bran is that, unless made into a mash with added  water, Bran tends to be dry and it could be inhaled which might irritate the horse’s respiratory tract.

How Do I Feed Bran?

If you want to feed Bran, or Bran mashes, it can be fed in amounts up to 5 to 7 percent of the horse’s total daily ration without causing harm.  If you want to bump up the fiber in your horse’s diet, or help a picky eater by feeding Bran as a regular part of the ration, you can gradually add a quarter-pound of Bran every three or four days until your horse is eating a pound of Bran daily.  This would keep the gut happy and be about 5 percent of the total ration.

If you want to feed a warm Bran mash there are a variety of Bran mash recipes commonly used.  There are even pre-made Bran mixes you can buy at your feed or tack shop.

Brittany's Bran Mash

If you buy the Bran in bulk you would want to use four to eight cups of Bran and add water until the Bran is well saturated. The proper consistency should result in the Bran clumping together if you grab a fist full and squeeze it.

Most of my clients add other things to the mash.  Oats, flavors like molasses, and of course plenty of chopped up carrots and apples.

Remember, however you decide to add Bran to your horse’s diet, make the change gradually made over a period of days or even weeks.  Sudden changes of any kind; new feed, different hay source or supplements can upset the microbial balance in the gut. This balance must stay stable for proper digestion, vitamin synthesis and overall health. But when a sudden change is made, it shocks the microbe population, and they die.

Not only does this affect the microbes ability to assist in proper digestion, but the dying microbes give off toxins that can be absorbed into the horse’s bloodstream causing all kinds of trouble for your horse.

~Peace and Good Feed,

The Nerd


  1. Thanks. Really informative. We had our hay tested and I was told that it is extremely high in calcium, low in phosphorous so I was thinking of feeding a handful of bran daily to my large pony. Sound reasonable to you? Thank you!

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