Most horse owners are likely acquainted with beet pulp, whether in the classic (molassed) form or the ‘de-molassed’ variety available under various brand names.
But what does beet pulp have to do with pectins? And what do they do in feeding?
Molasses pulp and unmolassed beet pulp
Beet pulp is an end product of sugar production and has also been used as animal feed since the beginning of industrial sugar production. After extracting the juice from chopped sugar beets to produce sugar, the fiber-rich residues are dried and made available in various forms as horse feed. The ‘classic’ beet pulp is blended with molasses, another by-product of sugar production, prior to drying (and potentially pelletization).
It can contain as much as 20% sugar!
For horses, however, ‘demolassed’ beet pulp (without added molasses) has gained popularity. Nevertheless, they still retain approximately 5-10% sugar.
© Adobe Stock / M. Makela and Alp Aksoy
Beet pulp, apple pomace and pectins
Pectins belong to the group of structural carbohydrates. These are large molecules made up of sugar building blocks that are formed by plants to give their various parts (stems, leaves, fruits) a solid structure. The different structural carbohydrates in plants exhibit various characteristics.
Pectin contributes to stability and, most importantly, elasticity due to its ability to bind significant amounts of water, known as “gelling capacity.” It is therefore found in particular in flowers, leaves, fruits and roots.
Beet pulp, being the structural component of the sugar beet root, is naturally abundant in pectin. The same holds true for apple pomace or citrus pomace. In the food and pharmaceutical industries, pectin is frequently employed as a gelling and stabilizing agent for products such as jams, confectionery, ointments, gels, creams, and more, thanks to its water-binding capabilities. Whenever a product requires a more solid yet elastic texture.
It is listed as food additive E440.
Pectin for the food industry is typically extracted from beet pulp (the byproduct of sugar production), apple pomace (the residue from apple juice production), or citrus pomace (the residue from orange and grapefruit juice production).
Due to their gelling properties, which result in a slimy consistency when combined with water, pectins are believed to be beneficial for digestion and the formation of mucous membranes, such as those found in the stomach and intestines.
Pectins as animal feed
Pectins are not only utilized in the food, cosmetics, and pharmaceutical industries. They are also used as feed for various animal species. Pectins are highly digestible by pure herbivores such as cattle or horses, unlike in dogs or humans, where pectin acts as indigestible fiber and is mostly excreted in the feces. It is crucial to pay attention to the intended animal species for which pectins are used.
In cattle, feed rich in pectin is utilized as fattening feed, contributing to faster weight gain due to its excellent digestibility. This is exactly what we don’t need for our horses.
Besides the elevated energy supply, there are other factors that argue against pectin-rich feeds, such as beet pulp or apple pomace, for horses.
Effect on the microbiome of the large intestine (‘intestinal flora’)
Due to their remarkable gelling ability, pectins are believed to promote digestive health, particularly in the stomach. But, as is so often the case, the reality is a little more complicated.
Pectins enhance intestinal peristalsis, facilitating the swift transit of food pulp through the intestine. Accelerated intestinal peristalsis is also responsible for the occurrence of diarrhea in some horses when exposed to fresh, young grass. The younger the grass growth, the higher its pectin content. As the grass matures, it accumulates more fiber in the form of cellulose, hemicellulose, and lignin, typically normalizing peristalsis.
As pectins are not digestible in the equine small intestine, they reach the large intestine. There, they function as a nutritive substrate for a specific bacterial strain. An abundant supply of pectins can facilitate their rapid proliferation, inducing a shift in the microbiome, commonly referred to as dysbiosis. DELETE
Lactic acid bacteria primarily, and to a lesser extent protozoa, are responsible for the breakdown of pectins in the horse’s cecum and large intestine. These are the unwelcome inhabitants of the large intestine, capable of breaking down not only pectins but also the more commonly known fructans.
Feeding beet pulp or apple pomace thus encourages the proliferation of bacteria that, in the worst-case scenario, can cause a decrease in pH in the large intestine (“hindgut acidosis”) and potentially trigger laminitis.
Therefore, it is now suggested that many cases of laminitis during spring grazing are not attributed to high protein levels in the young grass but rather to the elevated pectin content in a microbiome that has undergone a shift. If you regularly feed “demolassed” beet pulp or feed containing apple pomace over the winter, you should not be surprised at the weight gain and laminitis in the spring.
Against this background, it is also extremely questionable that “demolassed” beet pulp is repeatedly advertised as “healthy concentrated feed” for horses with existing laminitis problems.
Horses with metabolic disorders, in particular, should not be fed pectin-rich feed.
Even in healthy horses, a shift in the microbiome in this direction can have detrimental long-term effects. Regularly feeding beet pulp, even in its ‘de-molassed’ form, may eventually result in a metabolically compromised horse in your stable.
© Adobe Stock / Bronwyn Photo
It is now well-established how crucial maintaining a healthy and diverse intestinal flora, as well as a stable neutral pH in the large intestine, is in preventing many diseases, ranging from laminitis to sweet itch. Consequently, it’s imperative to avoid one-sided shifts in the large intestine microbiome caused by certain feeds.
Conclusion
In summary, it can be concluded that
feedstuffs rich in pectin, including de-molassed beet pulp, apple pomace, citrus pomace, etc., are not appropriate as healthy horse feed.
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