It only takes one trip to the feed store to marvel at the vast array of equine feed products. The well-stocked shop also features a wide variety of forage, from baled hay to chopped, cubed and pelleted options.
All of those products must pass through the equine digestive tract and every horse—no matter the breed, age or riding discipline—has the same digestive process. The more you understand this process, the better you can provide your horse with a feeding program targeted to his needs.
You’ve no doubt heard some astonishing figures about the horse’s digestive system. It’s true that if the entire digestive tract were stretched out, it would be approximately 100 feet long.
The horse’s stomach is relatively small compared to his size, and although digestion begins here, food isn’t meant to stay in the stomach for long.
After exiting the stomach, food enters the small intestine where most nutrients are absorbed. Any food material not digested in the small intestine moves on to the hind gut (the cecum and large intestine), where microbial fermentation takes place. Feed matter can remain here for many hours as the bacteria that naturally populate the hind gut ferment and break down the plant fiber, extracting the most possible nutrition from the diet.
Problems can arise when the horse eats too fast, doesn’t chew his feed properly, or is fed too much at one time. Any of these scenarios may create excessive fermentation and gas, which do not result in healthy digestive function.
“As a rule of thumb, it takes 24 hours for food to pass completely through the horse’s digestive system. The feed only takes about 1-1/2 hours to move through the upper intestine; the rest of the time it’s moving through the hind gut,” explains Gary Potter, PhD, PAS, ACAN, of Potter Enterprises, an international consulting business for the horse industry and the equine feed industry. Dr. Potter taught equine science, nutrition and physiology courses at Texas A&M University for 35 years.
The equine digestive process is dependent upon a healthy population of beneficial microorganisms. In fact, it can’t function properly without these “good bugs.” They help regulate the pH level of the intestine, which prevents detrimental microorganisms from growing. They also produce antibiotic-like substances and certain enzymes that act on and kill many harmful bacteria, viruses and fungi. Helpful microorganisms also neutralize toxins produced by harmful bacteria.
These beneficial bacteria and the horse have a symbiotic relationship. The horse needs them for digestion to proceed without disturbance, and the bacteria have a safe environment inside their “host.”
Upsetting the Apple Cart
You’ve probably heard that you shouldn’t make sudden changes in your horse’s diet, but do you know why? It’s all about those “good bugs.”
An abrupt change in feed—especially concentrates—can kill off those beneficial bacteria living in the hind gut. They’re no longer present to aid the digestive process and when they die, toxic substances are released. In addition, their die-off allows harmful, opportunistic bacteria to increase in number, and can lead to gastrointestinal disturbances.
A sudden change in diet isn’t the only thing that can endanger the population of beneficial bacteria in the equine GI tract. Stress is another culprit and can be caused by travel, competition, and changes in routine. Some medications can also negatively impact the digestive process.
Equine nutritionists recommend changing concentrates, hay and forage gradually over a week’s time. This gives the beneficial bacteria time to adapt to the new food source. You may also want to feed a digestive support supplement during times of feed change and potentially stressful situations.
Offering Digestive Support
Many horse owners feed dietary supplements designed to help replenish the beneficial bacteria in the equine digestive tract. These supplements introduce live bacteria and microbes into the horse’s system in an attempt to maintain the population of “good bugs.”
Probiotic supplements may include microorganisms, fungus, and yeast; all specific live beneficial bacteria meant to aid digestion.
Prebiotic supplements contain substances identified as preferred food sources for beneficial bacteria. These substances aren’t digested by the horse, but by the bacteria in the horse’s gut.
A “synbiotic” is a nutritional supplement containing both probiotics and prebiotics.
Potter points out that probiotics might be helpful for a horse that had experienced digestive troubles, such as diarrhea and loss of gut microflora.
“Any situation—stress, abrupt change in diet, parasitism, etc.—that would increase the rate at which ingesta (food) passes through the digestive tract, thus allowing less time for digestion, might create a need to help sustain adequate gut microflora by diet supplementation,” notes Potter.
You can help your horse’s digestive system function as Nature intended by paying careful attention to your feeding routine. Provide quality forage, and feed a commercial concentrate designed for your horse’s needs when forage alone isn’t enough. Create a feeding routine that mimics natural grazing by offering free-choice grass hay and don’t allow the horse to go for long periods without eating. Always ensure fresh, cool water is available, and offer a digestive support supplement when needed.
In order to know you’re choosing a high quality supplement, look for a product that carries the NASC Quality Seal. This provides assurance that the product was made by reputable company that is a National Animal Supplement Council member. In order to display the NASC Quality Seal, members must meet specific standards and successfully complete a meticulous facility audit.