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Pre and Probiotics in Horse FeedPre and Probiotics in Horse Feed: While scanning information about various horse feeds, you may have come across the phrase ‘contains prebiotics and probiotics’….Hmmm, sounds impressive, but what are they, what do they do for your horse, and why are they important?  Pre- and probiotics are considered “functional ingredients” that are added to horse feed to provide benefits to your horse. Here is some information about them. For example, what they can mean for the digestive tract and overall wellbeing of your horse.

It starts with the gut. The environment of the intestine (a.k.a. gut) contains naturally occurring beneficial microorganisms commonly called  ‘bugs’. All species have gut bugs. For example, humans! They are essential to the digestion process.

For the horse, gut bugs work to break down components of forage and feed. This happens as they pass through the digestive tract.  The bugs deconstruct complex molecules within feedstuffs, which releases nutrients and allows the synthesis of energy substrates and important vitamins. Those nutrients are then absorbed. Through the intestines into the bloodstream. There they become available to cells in the body to support basic maintenance, growth and activity.


Feed that is broken down and digested more completely allows for more nutrients to be readily available for absorption.  This is essentially what probiotics do. Adding probiotics to a horse feed means adding more beneficial bugs to the existing population in the horse’s gut.

Probiotics such as yeast culture, work with the naturally occurring bug population to enhance the digestive process, further breaking down complex protein and fiber fractions in the gut and making them more available for absorption into the blood stream. 

As a probiotic, yeast culture has also been shown to balance and stabilize the digestive microbial ecosystem in the cecum of the horse, as well as help prevent the colonization of bad bacteria in the gut. 

A stable microbial ecosystem is beneficial to the horse beyond improvements in digestive and absorption efficiency, it also reduces the risk of digestive upset, such as gas colic, that a horse might experience with changes in feed or hay, or while under stress from transportation, shows, changes in weather or other.


Prebiotics can be thought of as an energy jolt for the gut bugs. They are a rich nutrient source for the gut bugs (e.g. lactobacilli, bifidobacterial). Which in turn stimulates their growth and activity, making them more effective at their job.

Research has shown that prebiotics help stabilize the population of gut bugs even through sudden changes in the diet. This helps to reduce incidents of digestive upset.  For performance horses who require energy dense diets that include higher levels of starches and sugars, prebiotics can help reduce the incidence of digestive disorders and support optimal performance. 

Prebiotics such as inulin and oligofructose are selectively fermented by the gut bugs. This stimulates their growth and activity. This benefits the horse by enhancing the absorption and retention of certain minerals. In turn, this can support the immune system, skeletal tissue, and more.

The population of bugs in the gut are sensitive to changes in their environment. Stress, illness or the ingestion of undesirable materials bring on these changes. As a result, the addition of pre- and probiotics to a diet has been shown to be beneficial in reducing the incidence of digestive upset, namely diarrhea.

For senior horses, the use of pre- and probiotics in feeds has been shown to improve the digestibility and absorption of nutrients, which can translate into an enhanced quality of life.  

In conclusion, pre- and probiotics work with the naturally occurring gut bugs to support optimal gut health, aid in the digestion process, as well as provide a buffer against negative bacteria.

Visit Olsen’s for all your horse health needs! Check out our feed and supplement selection here.

Article Source: Gina T. for Nutrena’s The Feed Room