Nutritional Management Of Horses: Is Psyllium A Player?

The Role of Psyllium in Horse Nutritional Management

Today, there are a plethora of nutritional products such as psyllium on the market. This growth in product offerings has brought confusion with information that circulates on “how to feed horses.” One source of confusion includes the use of products to prevent colic. Since nutritional management has always been a focus, the following information should help horse owners make better judgments concerning products that promote a laxative effect.

Objections to Bulk Laxatives

The fundamental objective in feeding bulk laxatives to any animal (including humans) is to force the gastrointestinal tract to contract differently and “to move” with more vigor. The gut is a muscle and with contractions the contents of the gut will move through the pipeline. As the gut contracts with more vigor, gut content will move through the gut at a faster rate. The standard for scientists in which the movement of the gut’s content is measured is referred to as the rate of passage (ROP) or transit time (TT).

The Role of Fiber Intake in Horses

Remember that most adult horses’ diets consist primarily of forages, which is hay or pasture. These feedstuffs contribute the fiber for the bulk of the diet. Fiber sources not only provide sources of energy and nutrients but also contribute to gut integrity. Gut integrity requires a stable, healthy microbial population that resides in the gut. More detailed information regarding the emphasis on fiber intake via forages can be found in Dr. Bray’s Corner. Check out the article on Feeding Guidelines for Horses.

Is There Really a Need for Psyllium?

So, if a horse is fed a diet high in fiber, is there a need for a psyllium product to add bulk or to provide a laxative effect? The apparent recommended feeding amount of various psyllium products approximates 2 – 4 ounces per day. There are different regimes promoted that include daily feeding to feeding for 5 – 7 days per month. Keep in mind that fiber is a fundamental component of the diet that influences ROP.

For example, 4 oz. of  psyllium provides less fiber than 1 cup of wheat bran. For comparison, if an 1,100 lb. horse is fed Bermuda grass hay at 1.5% of body weight, this provides 350 times more crude fiber than 1 c. of wheat bran. It also provides 420 times more fiber than 4 oz. of psyllium. Thus, the amount of fiber provided by 4 oz. of psyllium and 1 cup of wheat bran is insignificant relative to contributing bulk to the diet in the form of fiber.

Other Horse Industry Claims About Psyllium

The claim that circulates in the horse industry is that psyllium “picks up sand” in the gut. Another recollection of psyllium lore was correlating the action of psyllium to “a wad of gum rolling-along inside a tube with sand sticking to the wad”. If you think about these assertions, hopefully you will conclude that psyllium is perhaps provided more credit than it deserves. Remember, psyllium is exposed to enzymatic and microbial digestion just like every other feedstuff in the diet. The idea that psyllium selectively “picks up sand” and ignores all other digestive particles in the gut lacks sound reasoning. Psyllium does provide laxative-like properties, but are the amounts recommended adequate? I do not believe so. Perhaps if fed daily at sufficient quantities it may cause the gut to contract with more vigor, but the amounts would be costly.

How Much Fiber Does A Horse Need?

So, what are sufficient amounts of fiber? Frequently the known benefits of human nutrition have been used to justify a product’s application with horses. This is misleading. Humans are not non-ruminant herbivores. We do not have the hindgut capacity, the same number of compartments, nor the gut length of horses; therefore, horses have different dietary requirements.

Recommended fiber intakes for humans are 25 – 35 grams/day, although the average intake for most people is less than half of that. The fiber recommendation for an 1,100 lb. adult horse of 2,000 g. crude fiber or 2,300 g. ADF per day. There is a difference in how fiber is measured. Humans use total dietary fiber (TDF) while with horses acid detergent fiber (ADF) or crude fiber (CF) is used. TDF is more inclusive, but the difference in measurements doesn’t interfere with the principle that the requirements are totally different quantitatively.

Granted, fiber intakes have not been clearly established for horses, but suggested fiber requirements are implied by recommended forage intakes. For horses, 1.8 g. of crude fiber or 2.1 g ADF for every lb. of body weight is recommended. This determination evolved from years of experiences and industry research. Having forage analyzed and mathematically determining the fiber requirement is not practical, but there are known standards about forages and its composition. This is why we recommend feeding a minimum of 1.4 – 1.5% of the adult horse’s body weight in hay for horses that do not have pasture.

Psyllium and Colic

Feeding psyllium for colicky horses are frequently accompanied by several other recommendations. As you review the following nutritional management recommendations, ponder what has more influence on the horse’s gut, the nutritional management recommendation of the diet or feeding psyllium.

Colic is a serious ailment. Horse owners will spend more time with their horses that have been sick, including frequently checking on them and exercising them more frequently. So what does exercise do for the horse? Exercise will increase water intake (providing lubrication) and increase the contraction of the gut, regardless of the level or type of exercise. Exercise and water are perhaps the two best natural and cheapest nutritional management components that can contribute to the “laxative effect“.

Nutritional Management Recommendations

Recommendation: Feed more hay
What Does It Do?  An increase in hay intake will increase the water intake, thus more fiber and more gut fluids. Both are effective in influencing the contraction of the gut.

Recommendation: Feed the hay portion of the diet more than two times per day
What Does It Do?  Feeding roughage more than the traditional two times per day will reduce the hay spread along the ground and loss. More feedings will influence a consistency in gut contraction.

Recommendation: Feed hay in elevated hay-racks over a feed trough
What Does It Do? Most likely this will reduce the horse browsing the ground for hay and reduce hay loss spread over the ground.

Recommendation: Place rubber mats under the hay-rack or feed on rubber mats
What Does It Do? Most likely will reduce the opportunity for ingesting sand while browsing the ground for loose hay. Of course you will need to make it a daily routine to sweep the rubber mats.

Recommendation: Exercise the horse
What Does It Do?  Horses that exercise will drink more water. Water is also a lubricant of the gut. An increase in water intake will increase the ROP.

Maintaining a Healthy Gut in Horses

Horses are browsers. Hay is processed in an imperfect system in which foreign objects and particles are picked up during the cultivating and baling processes of hay. Efforts to eliminate harmful effects of foreign materials feared by horse owners, including sand, by feeding laxatives aren’t practical.

Another question evolves from those colicky horses that were treated clinically. Clinical treatments of colic may include 1 lb. of psyllium mixed with water administered via naso-gastric tube. The benefits of this treatment are evident. Not only does the treatment involve a large quantity of psyllium but also a large volume of water administered directly into the stomach.

Mineral oil may also be part of the mixture to provide lubrication. Keep in mind that the gut of a colicky horse has been compromised and horses have usually been off feed and water. Therefore, the gut content is less than normal and gut activity has been compromised. One can now reason how horse owners have extrapolated the clinical benefits of psyllium to daily use. Popular press articles have touted a variety of dosage/frequency recommendations, even as high as 1 lbs. of psyllium for a 1,000 lb. horse.

Economical Soluble Fiber for Horses

There are fiber-containing feedstuffs, called “soluble fiber” sources, that can partially be broken down by microbes that reside in the gut. This pre-cecal digestion property of “soluble fiber” sources encourages gut mobility and can be fed economically at much larger quantities. Beet pulp and soybean hulls are common sources of soluble fiber. Every Integrity product contains one or both of these fiber sources as a major ingredient.

Summing It All Up

So, what works to maintain a healthy gut? Consistency in feeding protocol, feed daily adequate levels of forage, frequent feedings of the daily forage allotment, feeding balanced formulas high in beet pulp and soy hulls, and common sense relative to nutritional management, exercise and water.