Skip to content
Bay horse looking over a fence with nothing to eat

Browse all Blog Posts by Topic

Equine Gut Health - The Need for Feed

Meeting your horse's needs for optimal gut health is not the same as meeting his caloric requirements.  If your horse is not underweight and basically healthy, suffice it to say his caloric (not necessarily nutrient) requirements are being met. Considering horses are grazing herbivores and their digestive tract is designed for almost continual trickle feeding (16-20 hours a day) of fibrous feeds - the question isn't are you feeding enough calories - but are you feeding in a way that promotes optimal gut health?
Read on to learn why gut health is so important, how common feeding practices affect it, and how to improve it by feeding more in line with your horse's digestive tract design.
Two horses eating hay

Why is Gut Health Important?

Approximately 80% of your horse’s immune system resides in the digestive tract. The microorganisms that reside there:
  • Contribute to stimulation of the immune response
  • Help protect against pathogens
  • Neutralize toxins

Horses require a well-balanced population of microbes in their digestive tract to enhance digestion and absorb nutrients (not necessarily calories). Some of these microorganisms are essential for manufacturing necessary nutrients as well.

Factors that can disrupt healthy populations of equine microorganisms include:
  • Feeding a new load of hay
  • Changes in forage type
  • Changes in type and amount of grain fed
  • Decreased access to pasture
  • Age
  • Fasting
  • Stress
  • Medications
  • Anesthesia
Maintaining a healthy and stable gastrointestinal ecosystem is vital to your horse's overall health.

How Rate of Consumption & Meal Size Affect Gut Health

How quickly your horse eats and how often you feed affect both his digestion and populations of beneficial microorganisms (the good bacteria).

Meals that are quickly consumed reduce the optimum time necessary for each distinct region of the digestion tract to properly digest and prepare forage as it advances from ingestion to excretion (Mouth > Stomach > Small Intestine > Large Intestine). Once the stomach becomes two-thirds full it begins to empty regardless of how well the particles are prepared to advance to the small intestine.

Prolonged periods of fasting (between meals or overnight) can create stress and:
  • Contribute to an acidic pH environment in the digestive tract
  • Induce gastric ulcers
  • Influence less than optimum beneficial microorganism populations

It is important to note that the pH environment of the digestive tract directly influences beneficial microorganism populations. Optimum pH levels are best achieved by providing a steady flow of appropriate forage/fiber

Feeding by Natural Design vs. Domestication

The horse's digestive tract was designed to process small amounts of continual forage (high fibrous feeds) while moving about. This combination of eating and moving helps create a healthy gut and  satisfies natural instincts. Trickle feeding allows for fiber to be present throughout the entire gastro-intestinal tract at all times. This maintains and feeds the crucial microorganism population as well as maintains an optimal pH environment.

Wild horses living naturally according to their design.
Horses confined waiting for their next meal.
And there are other benefits as well.  Nibbling throughout the day and night on appropriate fibrous feeds helps to prevent large swings in blood glucose concentration and can prevent overwhelming the hindgut (cecum and large colon) with undigested starch (reducing the pH to less than optimum levels). Starch is primarily digested in the small intestine. Unnatural pH levels can adversely affect the population of beneficial microorganisms in the large intestine.

Movement is also important to gut health. Mobility stimulates gut motility, effectively keeping the hindgut weighted (to encourage continued travel of undigested material motile). Muscles responsible for movement of the gut are better toned when utilized and can atrophy.

In nature, the horse's activities consist of traveling to water sources, walking and grazing, interacting with herd mates and periods of rest. They will voluntarily take breaks to sleep and rest for periods of time, typically no longer than an hour.

Domestication, typically, does not mimic nature's design. Common domestic scenarios contributing to less than optimum gut health are:
  • Turn out during the day to graze on pasture and confined to stalls at night with a small meal of hay that is quickly consumed. 
  • Confined in a corral or stall with no pasture and fed breakfast, lunch and dinner in equal amounts - leaving overnight as the most prolonged period of time without forage.
  • Kept in a dry lot and fed 2 large meals of hay (breakfast and dinner) typically consumed in 1-3 hours.
In domestication, involuntary periods of time without forage can be physically painful and mentally stressful. Mental and physical experiences are synonymous in that each has an influence on the other. ​

According to Martine Hausberger, PhD, director of the Laboratory of Animal and Human Ethology, a branch of the French national research center (CNRS) and the University of Rennes:

”It is also known that horses can experience gastrointestinal discomfort if deprived of food for a mere one to two hours.”

Ways to Improve Gut Health

Not every horse lives in a natural environment; however, there are ways to help mimic a more natural digestive process. Consider these options to help improve gut health:

  • If you feed meals, allocate hay across a 24 hour schedule. For example, if you feed 24 pounds of hay a day (24 hours) = 1 pound per hour. Say you feed breakfast at 8:00 AM, lunch at 1:00 PM and dinner at 6:00 PM. Breakfast should be 5 pounds, lunch 5 pounds and dinner 14 pounds - this ensures your horse has enough to nibble on during the 14 hours between dinner and breakfast. Remember, horses sleep only 3 to 4 hours in a 24-hour period and usually no longer than 20 minutes at one time.
  • If you feed loose hay, implement slow feeder bags or nets and provide multiple locations. If your horse is overweight, slow feeding will help to regulate insulin spikes, metabolism, and secretion of cortisol. For underweight equines, it can improve digestion, assimilation of calories and nutrients by increasing chew time per pound. See our Free Choice Forage Action Plan for more suggestions.
  • Most slow feed manufacturers are willing to offer advice on mesh sizes and the most appropriate slow feed solution for your individual environment and weather conditions. Take advantage of their knowledge and experience.
  • Provide as much turnout as possible with access to free choice forage (pasture, loose or slow fed hay). Learn more about choosing the most appropriate free-choice hay: Beyond Low Sugar/Starch - Choosing Hay for Weight Management
  • If access to pasture is limited due to concerns of caloric intake, use a grazing muzzle in pasture and turn out when sugars are likely to be lowest. Provide hay in slow feeders when not in pasture.  

In Closing

The horse's digestive tract is designed to suit a natural lifestyle (trickle feeding and moving). We can optimize gut health - and have happier, healthier horses - when we mimic this lifestyle within domestication.

Striving to trickle feed, encourage movement and allow your horse access to forage 24/7 may seem contrary to meals and confinement, but we can make positive changes and have options to work with. 

Helpful How To Resources


Browse all Blog Posts by Topic

Stay Connected

Follow us on Facebook for educational daily posts - Pinterest & Instagram too!

​Want to Hear About $ales, Nutrition Tips & Giveaways?

Be the first to know by subscribing to our monthly newsletter.

Monique Warren, Hay Pillow Founder with the Hay Pillow Slow Feeder product line - standard ground hay pillow, mini hay pillow, hanging hay pillow & horse trailer manger hay pillow

About the Author

Monique Warren invented the Hay Pillow® slow feeder and is the owner of Hay Pillow Inc. ​Warren has been an equine guardian for over forty years and slow-feed advocate for over 10 years. She contributes equine nutrition, digestive and hoof health articles to publications such as Equine Wellness, The Journal, The Naturally Healthy Horse, Natural Horse Magazine, Nicker News, The Horse's Hoof and Miniature Horse World Magazine. Equine nutrition and horses feet are her passions. She resides in Southern California.

Monique's Story

Leave a comment