Few feed room substances inspire as much anxiety as dry beet pulp. Some say that without proper soaking, it will expand in a horse’s stomach and cause colic or ruptures. Others worry it might swell during mastication and cause choking.

Even the manufacturer labels tend to recommend a minimum of 30 minutes soaking prior to feeding. But is it mandatory?

Most experts say no for most horses. Although soaking has benefits, the nature of a horse’s digestive tract prevents even large quantities of dry beet pulp from posing the commonly imagined threats.

While there are plenty of good reasons to soak beet pulp, there’s no truth to the common myth that feeding it dry could cause your horse’s stomach to rupture. Kimberly Loushin Photos

Tania Cubitt, Ph.D., and a consultant at Performance Horse Nutrition, said several factors keep beet pulp from expanding to fill a horse’s stomach the way it expands in a five-gallon bucket.

“The whole idea that beet pulp is going to make your horse’s stomach explode is just not possible,” Cubitt explained. “There’s simply not enough liquid in a horse’s stomach to make it swell. If you’re feeding a pound of beet pulp, you’re probably adding a couple of gallons of water to it and watching it expand. There’s not that much liquid in the stomach.”

The structure of the equine stomach also makes overfilling with beet pulp impossible.

“I think some of the fear comes from the fact that unlike cows, horses can’t regurgitate; once it goes in it’s going to stay in,” Cubitt said. “But that said, it flows through the stomach rather quickly. It’s going to flow into the small intestine and get through to the hind gut where fibers are meant to be digested pretty quickly.”

As the stomach fills, it releases a hormone called motilin, which prompts the movement of food into the small intestine and hindgut. Although equine stomachs can only hold two to four gallons of food at a time, the small intestine holds anywhere from 12 to 17 gallons, while the hindgut can accommodate as much as 40 gallons—more than enough volume to allay concerns over an over-full tummy from a single meal.

Of more concern is choke, where something that has been ingested—usually concentrated feed—blocks the horse’s esophagus. U.K. veterinarian Graham R. Duncanson looked at 60 horses that had come to the Westover Veterinary Centre for choke in a retrospective study, which was distributed by the American Association of Equine Practitioners as a tutorial. Of those horses, 47, or 76%, had ingested standard mixes of concentrated feeds, while dry beet pulp and “grass nuts” led to choke in three horses. The remaining 10 choked from causes as varied as lawn clippings, carrots, apples or grass. Yes, a horse absolutely may choke on dried beet pulp, but it also can choke on just about anything else!

The major factor that makes a horse prone to choke?

Feeding behavior, i.e. the amount a horse chews its food. “Think about it: What do you do when you chew? You put in saliva,” said Cubitt. “Saliva is a lubricant to help you swallow. If your horse is not chewing or chewing too quickly due to a number of behavioral issues, they’re not going to produce enough saliva, and it’s going to get stuck there in the throat.”

Dental issues are a major factor behind poor chewing. Of the 60 horses in Duncanson’s choke study, 52 had sharp, overgrown points on their lower molars, and he noted many other dental abnormalities as well.

Eating speed can also contribute to choke. Cubitt said stabled horses chew their food approximately half as many times as horses at pasture, who graze throughout the day. Even if you feed unlimited hay on the ground in the stall in order to mimic grazing, it’s different to chew hay than grass, according to Cubitt. “Grass has more moisture, and the fiber is a lot more digestible, so it’s going to take a lot longer to chew,” she explained.

“But it’s also different because when you decrease a horse’s stress levels, you slow down their rate of intake,” she continued. “We’ve got such a skewed idea of what unstressed, normal horses look like because most of our horses are never in that state. Sometimes even if you put your horse out in a pasture, it’s stressed because it’s never known that environment. But if you could see that same horse raised in a pasture get put in a stable, I guarantee you’d say, ‘Oh my, that horse is stressed!’ The more they feel comfortable, the more they’re just slowly chewing away. But when they’re stressed, they consume their food quicker.”

Cubitt also pointed out that horses in stalls generally don’t have access to constant food, which means they’re relying on humans to deliver meals throughout the day.

“If they don’t have food in front of them all the time, they don’t know when the next meal is coming,” she said. “So we have these horses that eat very quickly.”

But Soaking Makes Sense

For most horses—those without a risk factor like compromised teeth, a tendency to bolt their food, or a history of choke or impaction—feeding dry beet pulp poses little risk.

If you do want to feed it dry—due to factors like time constraints and weather conditions, it may make sense to opt for shredded beet pulp over pellets. A 2019 study led by Pauline Grimm, Ph.D., in France showed that while no horses in the study choked after being fed a significant amount of dry beet pulp, they did eat dry beet pulp pellets much more quickly than soaked pellets or dry shreds.

But if you can soak beet pulp, you probably should.

While soaking beet pulp may not be strictly necessary, there’s no downside to doing so.

“I recommend wetting everything—wet the beet pulp, wet the pellets, wet the hay,” Cubitt said. “Wetting it slows down rate of intake, which goes back to mimicking that slow grazing behavior, and it decreases the risk of impaction because you’re keeping the stomach moist, which helps replace some of the moisture horses get out at pasture from the grass that they’re not getting out of hay.”

Cubitt also recommends soaking other high-fiber forage replacements like alfalfa cubes, which, unlike beet pulp, can be hard and unpalatable if fed dry. However, like beet pulp, alfalfa cubes and pellets pose no risk to the digestive tract due to their propensity to swell.

Most of all, Cubitt stressed the importance of debunking myths surrounding beet pulp—myths that distract attention from the more common culprits of poor digestive health in horses and may prevent caretakers from choosing this valuable forage substitute.

“People say, ‘I won’t feed pellets,’ or ‘I won’t feed beet pulp’—they choose a thing that they won’t feed because it’s going to cause the horse to choke or do some horrible thing,” Cubitt said. “But nothing’s to do with what you’re feeding—horses will choke on grass if they’re hungry enough! Everything we do when we’re feeding horses, we
have to think about how can we make this mimic natural
equine feeding behavior.”

Is there a common practice in the horse world that you’ve always wondered about? Send your question to slieser@coth.com, and we might publish the answer in this series.

This article ran in the Oct. 5 & 12, 2020, issue of The Chronicle of the Horse.

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