Beet pulp has become a popular item to feed to horses. It’s my belief, though, that beet pulp is way overused. It does have a place in equine nutrition, but in my opinion that place is quite small.

Beet pulp is a by-product of the sugar industry. Along with sugar cane, beet roots are the major source of sugar for human consumption in the US. Beet pulp is what’s left after the sugar-rich juice is squeezed from the roots. As with numerous other waste products of the human food industry, the livestock industry has found a use for beet pulp. But if it weren’t for our insatiable need for sugar, we wouldn’t have even thought of processing beet roots as food for horses.

In fact, that’s my main beef with feeding beet pulp to horses. We use it mostly because it’s available, convenient, and relatively inexpensive. We use it because we can, and because it enables us to continue keeping horses in an unnatural and unhealthy way.

In my experience, horses do best when fed a diet that is as close to their natural diet as possible. Beet pulp is far removed from the natural diet of any herbivore. A small proportion of the horse’s natural diet does consist of roots and other fibrous plant parts, but beet pulp is hardly a good representation of the value of roots as food sources.

In general, the roots are a particularly nutrient-rich part of a plant. They acquire and store nutrients from the soil, and at certain times of the year they also store nutrients produced by the plant during its growth period. In fact, some herbalists describe the roots as the plant’s powerhouse. The roots of edible plants that have an enlarged root structure, such as beets and carrots, are especially power-packed food sources.

However, in the process of extracting the sugars from the beet roots, many other nutrients (vitamins, minerals, enzymes, cofactors) are squeezed out as well. What’s left is mostly fiber, some protein, some minerals, and a few vitamins. Beet pulp is a mere shadow of its former self.

The fiber in beet pulp is a little more digestible than that in mature grasses and legumes such as alfalfa, so per pound beet pulp provides a bit more digestible energy (i.e. calories) than grass hay and alfalfa hay. It is not as high in calories as grains and other starchy feeds, though. It is also lower in calories than high-fat foods such as rice bran and vegetable oil.

Table 1. The digestible energy content of various feeds, measured in megacalories (Mcal) per pound of feed.

Because of its slightly higher digestibility, beet pulp is added to the diet or fed in place of hay for hard keepers (horses who are underweight despite a seemingly adequate diet), horses with severe dental issues (especially senior horses whose teeth no longer grind efficiently), and horses with chronic digestive disturbances (colic, diarrhea, gastric or colonic ulcers). Because it tends to contain less dust, fungal spores, and other airway irritants and allergens than baled hay, beet pulp is also used to feed horses with heaves (reactive airway disease).

However, good quality grass or grass-alfalfa hay as pellets, cubes, or chaff (chopped forage) can also be fed in these situations. The horse’s system is designed to run on grasses, legumes, and other meadow and woodland plants, so wherever possible that’s what I recommend feeding. If the horse needs more calories than can be provided by grasses and legumes in whatever form, then the addition of a little grain, rice bran, or other calorie-dense food usually does the trick.

The addition of a digestive aid which contains brewer’s yeast (Saccharomyces cerevisiae) can also be useful. This yeast helps optimize fiber breakdown by the microbes in the horse’s large intestine, which helps the horse get more out of his forages. There are numerous digestive aids on the market which contain yeast cultures, but unless the horse needs extra digestive support, I’ll often recommend plain brewer’s yeast, which can be purchased in bulk at health food stores and some feed stores.

Beet pulp is also used in horses with chronically elevated insulin levels or severe intolerance of dietary starch and sugars. This includes overweight horses with insulin resistance (equine metabolic syndrome), older horses with uncontrolled equine Cushing’s disease, and some horses dealing with or recovering from laminitis unrelated to the first two conditions. The reasoning is that these horses can have problems with diets that are high in starch or sugars, and beet pulp generally is fairly low in these items, unless molasses has been added.

It’s become commonplace to refer to the starch and sugar content of a food as the NSC, or nonstructural carbohydrate, content (structural carbohydrates, in comparison, are the elements such as cellulose and lignin which give plant parts their structure and strength). The NSC content of beet pulp is about the same as that of the average grass hay or alfalfa hay, harvested after it has begun to flower.

Table 2. The starch and sugar content of various feedstuffs, given as the nonstructural carbohydrate (NSC) content.

The reason beet pulp is used for carbohydrate-sensitive horses is that its NSC content is fairly consistent, whereas the NSC content of grasses is more variable and can be quite high at certain times of the year (e.g. it may be over 30% in lush spring or autumn pasture, especially with “improved” pasture species). Substituting beet pulp for some of the grass hay ensures a fairly low NSC content in the total diet when the NSC content of the hay is not known or is higher than recommended for carb-sensitive horses.

I prefer to take a different tack with these horses. While I agree that it is important to keep the starch and sugar content of the diet fairly low, I believe it is even more important to feed a diet that is as close to the horse’s natural diet as possible. That means providing as much variety of plants as possible and including as much fresh, whole (i.e. unprocessed) plant material as is safe and available under the circumstances. And when fresh plant material is not available or advisable, I’ll use a blend of meadow herbs to expand the range of plant nutrients and sources.

In my opinion, feeding beet pulp just because it has a low NSC content is inferior to feeding a wide variety of moderate NSC foods, including some fresh, whole foods. There is way more to getting and keeping these horses healthy than just making sure they’re on a low NSC diet.

That is also true of the hard keepers, the horses with chronic dental or digestive disorders, and those with heaves. These problems call for a wholistic approach which considers the whole horse and the horse’s environment, management, occupation, and all of the other factors that contribute to health or disease. Adding beet pulp is not the answer on its own.