animal health consulting

Beet pulp is a byproduct of the sugar industry. It's the fibrous material that is left over once beet root, grown for its sugar content, has been squeezed of its sweet juice.

The particular varieties of beet root are grown as an alternative to sugar cane in cooler climates, where sugar cane doesn't grow well. I'm not interested in how the beet juice is refined into sugar for the human food industry; I'm interested in the leftover portion: the pulp.

Beet pulp is a waste product that someone, somewhere along the line, said, "Hey, y'know what? I bet we can sell this mountain of waste to livestock producers and horse owners."

And so a new horse feed entered the market; and by all metrics, it has been a stunning success. It's beeen a triumph of good marketing over good sense.

The upside

Here are the main selling points for beet pulp:

1. It is safer to feed than cereal grains, as it is very low in starch, while being a bit higher in calories than grass hay.

2. It is safer to feed than grass hays for horses with asthma, as it is generally low in dust, fungal spores, and other potential allergens.

3. It is more easy to eat than hay for horses with dental problems, as it is lower in fiber, and particularly lower in the types of fiber that are difficult to chew.

The downside

Here are the downsides that the marketing blurb doesn't tell you:

1. Beet pulp is a choking hazard; it needs to be well soaked before feeding.

2. Beet pulp is often mixed with molasses to make it more palatable (otherwise it's a bit like shredded cardboard).

As molasses is high in sugar, the molassed beet pulp products defeat the purpose of replacing cereal grains with beet pulp for horses who are metabolically vulnerable and need a low-sugar diet.

If you have one of those horses, be sure to buy plain beet pulp (i.e., no added sugars) — although I hope the next point will convince you that there are better things to feed your horse than beet pulp.

3. Beet pulp is high in rapidly fermentable carbohydrates, so it can increase the risk for colic and contribute to stomach ulcers.

On average, plain beet pulp (nothing added) is only 11-12% nonstructural carbohydrates (NSC), so it is generally considered a safe feed for "carb-sensitive" horses (i.e., those needing a low-sugar diet).

However, its NSC ranges from a low of about 2% to a high of over 20%, making it potentially risky for very carb-sensitive horses unless the manufacturer specifies their product's NSC content on the bag. So, if you have one of those horses, read the label before deciding to buy the product.

The bigger problem, though, is the proportion of NSC that is water-soluble carbohydrates (WSC). Almost all of the nonstructural carbs in plain beet pulp are water-soluble carbs: simple sugars, longer sugars (oligosaccharides, including fructo-oligosaccharide, or FOS), and fructan polysaccharides (aka fructans).

Most of the WSCs in plain beet pulp are simple sugars. That makes sense, given that the particular varieties of beet that wind up as beet pulp are selected and grown for their sugar content.

All of the types of WSC I listed above are rapidly fermentable by the horses's gut microbes, starting in the stomach.

Again and again, I've found that horses showing vague signs of discomfort or crankiness do better when beet pulp is removed from their diet, or at least dramatically decreased. That's because horses cannot vomit or even burp. So, when a highly fermentable feed begins to ferment in the horse's stomach, there's no way for the horse to relieve the resulting discomfort when the stomach wall is stretched.

It is also possible for the organic acids produced by microbial fermentation to cause or contribute to ulceration of the stomach lining. More often than not, though, beet pulp is more of a contributing factor than a causal one.

This feature is used as a selling point, as it makes beet pulp a little higher in calories and a little more digestible than the average grass hay. But