Equine Hindgut Health: How and why you should feed microbes?

By Suzie Middlebrook, BSc. | Cavalor Nutrition Specialist

Conscious horse owners are often extremely particular about what they feed their horse. A large amount of time, effort, and planning may go into making sure the horse is being fed the right combination of hay, grain, and supplements. And while the horse is the one we watch eat all these carefully calculated and measured portions of feed, they aren’t the only creature being fed in this scenario. In fact, several millions of billions of others are benefitting from the horse owner’s careful decisions as well.

In case you have already guessed, these are the microbes that are found primarily in your horse’s hindgut, including the cecum, which is a large vat of microbial fermentation found attached at the junction between the large and the small intestines, and the large intestines. While there are some smaller populations of fermentative microbes found in the stomach and the small intestine, these aren’t known to have as significant of an impact on the overall health of the horse as those found in the hind gut.

The microbial populations found in the hindgut of the horse are beneficial and critical to the wellbeing of the horse. The majority of these microbes are fiber fermenters, meaning that they take the fibrous portions of the horse’s meal that the horse can’t break down to use for their own purposes. This includes the structural carbohydrates found in forage called cellulose and hemicellulose. A major by-product of this microbial fermentation is volatile fatty acids or VFAs. These VFAs are chains of fatty acids which can then be used by the horse as a significant source of calories. It is currently theorized that VFAs may contribute an additional 20-40% more calories than what the horse is receiving in just his diet (Bergman, 1990). If a horse has a struggling microbial population, they may not be getting the number of calories that they could potentially be getting otherwise. This could cause the horse to drop weight as well as be more prone to certain conditions such as a compromised immune system and a higher risk of laminitis (Flickinger et al., 2003).

Some strategies that Cavalor® uses in our feeds to help support the sensitive microbial populations is by adding, essentially, “microbe food” to our grain mixes. “Microbe food” is more commonly referred to as prebiotics. The first nutraceutical we add is called Florastimul, which is a particular carbohydrate that is completely indigestible to the horse while easily broken down by the microbial populations (Campbell et al., 1997). Florastimul is found in a number of our feeds including Perfomix, Endurix, and Mash & Mix.

The second nutraceutical Cavalor uses is a blend of high quality fiber sources that are collectively called Fiber Plus. Fiber Plus includes whole or minimally processed high-fiber plant products such as flaxseeds, chicory pulp, and alfalfa stems which all provide complex sources of structural carbohydrates. The microbes will ferment these structural carbohydrate sources and make them into useable energy for the horse. In addition, the large fiber pieces associated with Fiber Plus also makes the feeds that utilize this nutraceutical more appropriate for horses with ulcers. Fiber Plus is found in some of our more specialty feeds Strucomix Original, Strucomix Senior, and Fiberforce. These feeds can all be fed along with a grain-based feed for additional energy or by themselves.

Bergman, E. N. 1990. Energy contributions of volatile fatty acids from gastrointestinal tract in various species. Physiological Reviews. 70 (2): 567-590.
Campbell, J.M., G. C. Fahey, Jr., and B. W. Wolf. 1997. Selected indigestible oligosaccharides affect large bowel mass, cecal and fecal short-chain fatty acids, pH and microfloral in rats. Journal of Nutrition. 127: 130-136.
Flickinger, E. A., J. Van Loo, and G. C. Fahey. 2003. Nutritional responses to the presence of inulin and oligofructose in the diets of domesticated animals: a review. Critical Review of Food Science and Nutrition. 43: 19-60.