Ask Horse Journal: 03/06

Bran Mash
A friend of mine has recently moved her horses to her home and has been continuing practices that her previous barn taught her.?? Apparently the last barn she was at told her to feed bran mash more often in the winter months (daily) and to feed it without wetting it first.?? I was under the impression that bran mash should always be thoroughly wet first before giving it to a horse.?? Has there been a article or editorial written about this before’?? If so, what issue’?? Should I be concerned that the horses are eating large amounts of dry bran’

First, a “mash” by definition is a wet meal. Bran, and other high fiber things, are laxative in people because they stimulate the large bowel and are not digestible.

With a horse, if bran has not been a regular part of the diet and you suddenly feed some, you may very well end up with loose/softer manure. It’s not really because of a mechanical, stimulating laxative effect but because the organisms in the large bowel are disrupted by the new food type, which then results in diarrhea.

As the horse’s microbial population adjusts, manure will go back to normal, so long-term feeding of dry bran is not of any benefit in terms of preventing winter impactions. Water and salt are the most beneficial ingredients in a mash. It’s a good way to get some extra water into them, and the salt continues to encourage good drinking.????Bran is also a pretty good way to boost calories, if that was the effect they’re after.

Horses can and will eat bran dry, but??bran is often??dusty and a potential respiratory irritant. It may also be a??choke risk in horses prone to bolting or with histories of choke.

Speaking of choke, the myth persists that beet pulp cannot ever be fed dry or it will swell inside the horse and cause either choke or a ruptured stomach. Dry beet pulp, in shred or pellet form, is a major ingredient in many horse feeds and is no greater a choke risk than any feed or hay.

With plain beet pulp, the risk factors for choke are the same as they are for bran – insufficient chewing leading to low level of saliva production, bolting feed, and motility disorders in the throat or esophagus that predispose the horse to choke in the first place. Also as with bran, the biggest plus to a beet pulp mash is the water and salt you can get into the horse when you feed it. Beet pulp is particularly good for this because it will soak up as much as four times its original weight.


Manure Ingestion
My horse has been eating manure for a couple of days now. He’s getting good hay and oats. Is this a problem’ I thought that he was lacking minerals so I spread some on his oats for a couple of days. When he comes across the mineral he moves it and eats the oats. This tells me that he is not lacking minerals. His stomach is gurgling so I don’t think he has colic. Any info for this problem would be greatly appreciated.

All animals may eat their manure. In that respect, it’s “normal” behavior, but there usually is a cause. One is simply boredom. A horse with nothing else to do and not enough hay to keep him occupied may turn to eating manure. Animals also will eat manure if their diet lacks sufficient calories or protein.

There’s no evidence to suggest they do it specifically for mineral deficiencies (i.e. if calories and protein are adequate), although that can’t be completely ruled out. Another cause, which may be the case in this horse, is digestive upset. Foals appear to instinctively eat manure, a behavior that helps them populate their gut with the correct type of organisms. This instinct may be preserved into adulthood. For example, horses with diarrhea can often be observed eating manure. If the horse’s gut is gurgling loud enough to be obvious, that’s not normal. A recent change in feed, eating frozen grass or dead vegetation, etc. could have caused some digestive upset.??

Despite fairly widespread belief to the contrary, horses will not free choice minerals if they have deficiencies and they do not have any natural appetite/taste for any mineral beyond salt. Free-choice minerals that you may hear people say were eaten in great quantities for a while contain a palatable base: salt, molasses, alfalfa, etc. This is what the horse wants, not the minerals. Once the novelty wears off, or they begin to irritate their stomachs by excessive consumption, they stop.


We’ve read a lot about insulin resistance in horses and wrote an article about it because nobody in the Netherlands seems to know anything about the correlation of insulin resistance, founder and magnesium. We now also found a good supplier of magnesium-chelate. We’ve found if there are significant signs of a magnesium deficiency, a small pony needs up to 3 grams of magnesium per day, a big or heavy horse needs up to 12 gram of magnesium per day. We’ve got a 10% chelate (albion), which would mean that we have to feed a small pony 30 grams and a big horse 120 grams. Correct’ That amount should be fed for about six weeks, and if the signs don’t improve, quit because the problem probably wasn’t a magnesium deficiency. If it does improve, reduce the amount of magnesium to a half initial dose. It seems to me that it’s a large amount of magnesium to feed.

You’re correct that those amounts are of actual magnesium, so it would take considerable amounts of a chelate. However, those amounts are not based on chelated magnesium.

Chelates can improve the absorption of minerals in the small intestine but may be of little or no benefit in a horse because the volatile fatty acids produced by fermentation in the hind gut make the horse’s large intestine an important site of mineral absorption as well. You might want to consider using magnesium oxide instead, which provides about 8 grams of actual magnesium per tablespoon.

Although we still believe magnesium is an important mineral for animals with insulin resistance, this has not been formally studied yet.

The amounts you mention are OK for short term, but for long term, the amount fed should be based on a knowledge of the mineral levels already in the animal’s diet. Keeping the calcium:magnesium ratio in the diet at 2:1 seems to be clinically correct and safe long-term.

However, there’s more to combating insulin resistance and associated laminitis than just supplementing magnesium. It’s also critical to limit the level of soluble carbohydrates in the diet and watch all minerals and vitamins that play a key role, ensuring balance and intake.

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