Fiber in Horse Feeds

In our previous post, we learned what fiber is and how a horse digests it,and we also learned that a horse consuming 1-1.5% of it’s bodyweight in quality roughage will satisfy its daily fiber requirements.

When it comes to any grain sources that may be added to your horses diet, fiber plays a much smaller role since the amount of fiber that is added by grains is relatively little, but the effect and digestive process is similar. 

When feeding the grain portion of the diet, ensure that your horse is not receiving high quantities of grain meals all at once – typically no more than 5-6 pounds of grain per meal at most. Because grains tend to be higher in starch than roughage, feeding too much at once can overwhelm the small size and quick rate of passage of food through the stomach and small intestine, and allow starches to pass undigested to the hindgut. Digestion of starches in the hindgut releases lactic acids that are toxic to the fiber-digesting microorganisms, which can result in a gas colic episode or laminitis.

Generally speaking, when you look at a the tag from a basic equine ration, the higher the crude fiber level listed, the lower the energy content of the feed.  Of course, there are other factors that must be looked at, such as the fat level, and also possibly the sources of fiber. 

Beet pulp, for example, is often referred to as a “super-fiber” due to the high level of fiber it provides while also providing roughly the same energy level as oats.  While soy hulls and dehydrated alfalfa are common ingredients used to increase fiber levels, a performance horse ration with a higher fiber level may make use of beet pulp to achieve both increased energy and increased fiber levels.

Feeding Fiber to Horses

Do you know the fiber level in your current feeding program?  If you don’t, you are not alone.  Few horse owners can answer that question, and even fewer understand why it might be important or where fiber comes from.  The first and foremost source of fiber in a horses’ diet is their roughage, or hay, source.  Secondary to that is what is present in any supplemental grain sources.

First of all, let’s define what fiber is:

  • Fiber is a measure of the plant cell wall, or the structural portions that give the plant support. 
  • Main components of fiber are the digestible cellulose and hemicellulose, and the indigestible lignin. 
    • As a crop of hay matures, the lignin content increases and the cellulose and hemicellulose decrease.

Here’s what happens as a horse consumes roughage:

  • Some quick digestion occurs in the stomach and small intestine, allowing starches and sugars to get digested as the forages pass through this portion of the digestive system. 
  • The fiber begins to get digested as the feed passes into the hindgut, or the cecum and colon. 
  • Fiber is digested well here is because of the presence of billions of microorganisms (bugs) whose sole function is to digest fiber. 
  • These microorganisms break down fibrous feeds into short chain volatile fatty acids, which are a source of energy for the horse. 

Here is why it becomes important to feed a high-quality, early-growth-stage roughage.  As a plant matures, the lignin portion increases, reducing the energy available from that roughage.  Add that to the other benefits of high-quality roughage for horses, namely the greater availability of other nutrients, and it is easy to see where spending a little more money for better hay is better in the long run for your horse.

So what does it all mean for your horse?  A horse consuming 1-1.5% of it’s body weight per day in quality roughage sources will meet its fiber needs.