Now that I have your attention, wouldn't it be nice to feed stuff to a horse to have less to clean up later? If I had that answer I'd be retired and writing this article on some warm sunny beach. Trust me when I say I'm still looking for the answer. However, there are some things you can look for when trying to feed more digestible products to your horse. The term "bio-availability" is a term that is going to be discussed by more nutritionists in the future. Simply put, it means how well the nutrients fed are digested by the horse. If your horse is consuming products and you end up collecting them from the stall floor at the end of the day, how much money did you really save on that load of hay or that bag of feed?

Let's start with the horse's primary diet, fiber. Fiber is composed of cellulose, hemi-cellulose, and lignin. In the plant structure, cellulose and hemi-cellulose are able to be fermented in the hind gut of the horse by a microbial population. Lignin, on the other hand, is not fermentable. Lignin provides the strength to keep the stalk of plants from falling over. That is why tall pastures and overly mature hay does not provide much nutrition; the amount of lignin is very high. On the other hand, clipped pastures and immature or pre-bloom hay have very little lignin. Therefore, how you manage your pasture and buy your hay has a significant impact on your feeding program. Remember that just because the hay is green doesn't mean it is very digestible.

Fiber sources from standpoint of a bag of feed are very similar. Fibers sources such as shredded beet pulp, soy hulls, wheat midds and alfalfa meal are low in lignin and provide a good amount of calories. Some other fiber sources such as oat hulls, rice hulls, and peanut hulls would be high in lignin and not very digestible. Often the less desirable of the fiber ingredients are simply listed as "processed fiber by-products".

One story we hear all the time is that the horse is eating oats and just passing they through undigested. As an experiment for the strong at heart, pick out a piece of oat from the manure and what you will usually find is that the inside of the oat, where most of the nutrients are found, is gone and just the hull remains. This is proof that oat hulls are not very digestible.

Minerals are another nutrient that has a significant difference in bio-availability, depending on the source. Minerals are typically listed as oxides, sulfates, or some designation of an organic mineral. Digestibility of oxides is very low, but they are very cheap. Sulfates offer an improved level of digestibility and are more expensive. Finally organic minerals have significantly better digestibility over even sulfates and, of course, are the most expensive. Since there are many different forms of organic minerals, tag listing varies rather dramatically. Since they are often tied to a protein source, they would be listed at "proteinates". Feed companies often use a combination of mineral sources, but if organic minerals are not at least 25% of the total mineral supplementation, the benefit is lost.

Another way to improve digestibility of nutrients, both fiber and feed, is through the use of digestive aids. There is significant research on the use of yeast cultures on the improvement of fiber digestion and phosphorus absorption in the large intestine. Digestive enzymes help support naturally occurring enzymes in the small intestine. Probiotics help supplement the microbial population in the hindgut, especially during times of stress due to weather, exercise, shipping, etc.

Although I don't think terms horse owners often use, like "fillers" and "rich" have much merit in horse feeds, the concept of bio-availability needs to be considered. Check the ingredients on your feed tags and look for products that improve digestibility of the product. There are feeds on the market today that utilize less digestible ingredients to be able to sell at a cheaper price or increase the profit margin for the manufacturer. In the long run, they will usually cost you more by having to feed or supplement more or not provide the nutrition you think you are getting.