Exploring Prebiotic Feeds for Horses

Exploring Prebiotic Feeds for Horses

The equine digestive system is an intricate mechanism with each component (stomach and small and large intestines) having a specific duty to break down and ferment food. As horses are natural herbivores eating a variety of plant matter, their GI tract has evolved to process fibrous plant material efficiently, thereby providing them with the necessary nutrients and energy to remain healthy. Unfortunately, modern horse keeping practices, such as stable confinement, limited turnout and high grain diets, can disrupt the natural balance of their gut microbiota. A balanced diet is therefore vital to ensure a healthy gut, and prebiotic feeds have emerged as a valuable tool in achieving this goal. In this article, we will delve into the world of prebiotic feeds for horses, exploring why they are needed and offering a brief description of various prebiotic feed types.

Why Are Prebiotics Needed for Horses?

A healthy gut microbiome is crucial for horses for several reasons:

1. Nutrient Digestion: The gut microbiota assists in breaking down complex plant fibres, allowing horses to access nutrients from their forage-based diets effectively.

2. Immune Function: A balanced gut microbiome helps regulate the immune system, defending the horse against infections and diseases.

3. Gut Health: Maintaining a stable and diverse gut microbiota reduces the risk of digestive disorders like colic and laminitis.

4. Energy Utilization: An optimal gut microbiome aids in extracting energy from the diet, promoting overall vitality and performance.

Types of Prebiotics 

Prebiotics, in the context of equine nutrition, are non-digestible substances that serve as food for beneficial gut bacteria. By promoting the growth and activity of these beneficial microorganisms, prebiotics help maintain a healthy gut microbiome. Let's explore some of the prebiotic feed types that can be beneficial for horses.

1. Inulin and Fructooligosaccharides (FOS)

Inulin and fructooligosaccharides (FOS) are naturally occurring prebiotics found in various plants, including chicory root, Jerusalem artichoke, and dandelion greens. They are soluble fibres that resist digestion in the small intestine but are fermented by beneficial bacteria in the horse's cecum and colon.

These prebiotics promote the growth of specific bacteria, such as Bifidobacteria and Lactobacilli, which help maintain a balanced gut microbiome. Inulin and FOS can be added to a horse's diet as supplements or incorporated into commercial feeds.

2. Mannan-Oligosaccharides (MOS)

Mannan-oligosaccharides (MOS) are derived from the cell walls of yeast and promote the growth of beneficial bacteria like Saccharomyces cerevisiae in the horse's gut. MOS can help enhance the immune system and reduce the risk of digestive disturbances by preventing harmful bacteria from attaching to the intestinal lining.

MOS is often included in equine feeds and supplements designed to support gut health. It can be particularly useful in stressful situations, such as travel or competition, when a horse's immune system may be compromised.

3. Beta-Glucans

Beta-glucans are another type of prebiotic found in various grains and fungi. They are known for their immune-boosting properties. While beta-glucans primarily act as immunostimulants, they can indirectly support gut health by bolstering the horse's overall immunity.

These prebiotic feeds are often included in commercial horse feeds and supplements that aim to strengthen the immune system and promote overall well-being.

4. Soluble Fibre Sources

Certain soluble fibre sources, such as psyllium husk, can act as prebiotics for horses. Psyllium husk contains mucilage, a gel-like substance that can help soothe and protect the gut lining while also serving as a food source for beneficial gut bacteria.

Psyllium is commonly used to help manage digestive issues in horses, including sand colic. Feeding psyllium can help prevent sand buildup in the gut and support the microbial balance in the cecum and colon. Just remember, feeding psyllium husk for sand removal should only be done once a month for no more than 5 days. This is important, as if it is fed more regularly, the body will get used to the fibre and so it will be ineffective as a sand removal tool. 

Psyllium Husk can be fed as a pellet or in its natural form. Pelleted form often works best for sand removal due to the psyllium expanding in the horse’s gut, and it is often more palatable. Sand Flush and EAC Insand Out are two psyllium husk products that are used for the removal of sand.

5. Beet Pulp

Beet pulp is a widely recognised feed ingredient in equine nutrition. It is a byproduct of sugar beet processing and is rich in soluble fiber. While beet pulp is not traditionally classified as a prebiotic, its soluble fibre content can still promote a healthy gut microbiome.

Beet pulp is often included in horse feeds to provide easily digestible fibre, making it an excellent choice for horses with dental problems or those requiring additional fibre in their diet. The microbial fermentation of beet pulp in the cecum and colon can contribute to gut health.

A study* conducted in 2023 concluded that beet pulp increased short chain fatty acid production capacity, which in theory promotes overall gut wellness.

In Australia, there are two available beet pulp feeds, Hygain Micrbeet and Speedibeet.

6. Soybean Hulls

Soybean hulls are another feed ingredient that can have prebiotic effects in horses. They are rich in soluble fibre, providing a food source for beneficial gut bacteria. Soybean hulls can help promote microbial fermentation in the hindgut and contribute to overall digestive health.

Soybean hulls are commonly found in commercial horse feeds and can be a valuable addition to the diet of horses requiring extra fibre or those with specific digestive needs.

Benchmark Horse Feeds and Maxisoy are two products that contain soybean hulls. 

When considering prebiotic feeds for your horse, it's essential to consult with a veterinarian or equine nutritionist to determine the specific dietary needs of your horse. Every horse is unique, and their nutritional requirements may vary based on factors such as age, activity level, and health status. A tailored diet that includes appropriate prebiotic feeds can help your horse thrive and maintain optimal gut health, ultimately contributing to their overall quality of life.

*Ford, T., Z.L. McAdams, K.S. Townsend, L.M. Martin, P.J. Johnson, and A.C. Ericsson. 2023.Effect of sugar beet pulp on the composition and predicted function of equine fecal microbiota. Biology (Basel) 12(9):1254.