Mythbuster Monday: Feeding Warm Mash in the Winter Decreases the Risk of Colic

On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Does feeding warm mash in the winter decrease the risk of colic?

It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Does feeding warm mash in the winter decrease the risk of colic?  Does warm mash increase water intake? Read further to find out

Myth: Feeding warm mash in the winter decreases colic

Myth or Fact: Myth


Colic is one of the most common reasons large animal veterinarians get called out to a farm on an emergency. The word colic is an all-encompassing term that means abdominal pain and can include anything from a little painful gas to an impaction to a twist in a horse’s intestines. There are many reasons colic happens. Signs and symptoms of colic include lack of appetite, pawing, flank watching, biting or kicking, parking out and laying down and rolling.

During the winter months, there is an increase in colic cases in horses. The first reason is most likely due to a decrease in water intake, which slows the passage of food through the gastrointestinal (GI) tract. The second most common reason is related to the horse’s exposure level to the cold weather with the inability to stay warm and get out of the elements.

But does feeding a warm mash decrease the risk of colic?


According to veterinarian Bob Judd in the article Feeding Bran Mashes to Horses, bran mash is more closely related to oats and should be considered more as a grain rather than fiber. Because of this, feeding it regularly in the winter can create an unbalanced diet that is unhealthy for the horse. Judd states he does not recommend it and it is not effective in preventing colic in horses during the winter or at any time of the year.


An article by Grand Meadows stated this myth evolved due to the ability for mashes to increase a horse’s water intake. However, they also state that mashes do not give horses a substantial increase of fluid. Horses require five to 10 gallons of water per day. Because mashes do not give anywhere near that amount of water, it is not known to decrease the risk of colic.


Horse Illustrated published an article that also states that mashes do not increase water intake by enough that it would decrease the risk of colic. They suggest that rather than relying on mashes to increase water intake, you should instead give horses access to a salt block and plenty of water to entice horses to drink more.


Kentucky Equine Research provides the hard truth about mashes in their articleBran Mash: A Mashup of Myths. Here they state that equine owners feel that they’re doing something good for their horses; however, there is no proven benefit to feeding horses mashes in the winter. Many people like to believe that bran mashes have a laxative effect that aids in decreasing colic, but there is no science to back this notion. The article states that bran mash is fairly low in fiber and that beet pulp has a higher fiber content than mash.

Studies have shown that bran mashes have no increase in fecal water content after ingestion. The studies have also shown that if bran mashes are fed inconsistently in the winter, once per week or only when the temperature is extremely cold, it actually results in gastrointestinal upset. If you are feeding mashes consistently, know that stomach upset and colic may be more prevalent if the horse’s diet is not balanced with enough calcium. Mashes are high in phosphorus and need to be accompanied with calcium sources to keep the body balanced.


Equine Simplified also discusses bran mashes in their article. They state that mashes do not warm a horse up. Horses absorb heat in a different manner than humans and that while a mash may give heat immediately, the heat quickly vanishes. Horses should have forage to keep them warm because heat conversion is better from hay and lasts for a longer period while they’re eating it.


All of this research is further supported by the American Association of Equine Practitioners (AAEP), which shared this post on Facebook earlier this month:

The consensus is that warm mashes do not aid in increased water intake or warming up the horse. Horses need approximately 10 to 12 gallons of water a day and mashes do not aid in increasing water intake enough to meet this need. Also, mashes do not work as a laxative so they do not aid the bowel in moving contents out of the GI tract.

Do you have an equine myth you’d like us to tackle? If so, send it our way! Email your suggestions to [email protected]. Put Mythbuster Monday in your subject line.