Equine FEEDING FACT OR FALLACY
January 5, 2023
Shelley Nyuli with Kristen M. Janicki, MS, PAS .... Kristen M. Janicki, a lifelong horsewoman, was born and raised in the suburbs of Chicago. She received her Bachelor of Science degree in Animal Sciences from the University of Illinois at Urbana-Champaign and later attended graduate school at the University of Kentucky, studying under Dr. Laurie Lawrence in the area of Equine Nutrition. Kristen has been a performance horse nutritionist for an industry feed manufacturer for more than a decade. Her job entails evaluating and improving the performance of the sport horse through proper nutrition.
Fallacy #1: Feeding grain will cause a horse to colic
“A friend of mine read that feeding grain to horses will make them colic. Is this true?”
In its simplest form, colic is abdominal pain and can be caused by many factors. The horse’s gastrointestinal (GI) tract is long and complex with twists and turns, all of which are susceptible to distention, twisting, inflammation, or displacement. Yes, feed can be a cause of colic, but specific aspects of diet, feed characteristics, and management can all be partly to blame.
A horse’s risk for feed-related colic increases with:
- Total grain intake exceeding 11 pounds per day;
- Decreased or no pasture availability;
- Increased consumption of poor-quality hay; and
- Decreased water intake. (a consistent fresh water source is the most important nutritional need)
It is simply impossible to generalize all commercial grain products as potential causes of colic because they are intrinsically different. Yes, a large volume of any type of feed concentrate ingested at one time can cause colic, but other factors, such as sugar and starch, also contribute. Sugar and starch levels in grain products vary depending on the feed’s intended purpose. Racehorses, for example, rely on sugar and starch as their main source of energy and typically consume more than 11 pounds of grain per day, so they are at a higher risk for colicking. Compare that to a senior horse eating a high-fat and fiber feed at 6 pounds a day. His risk for having a feed-related colic episode is lower because of both the volume of feed per day and the ingredients.
The equine hindgut, which is another name for the large intestine, houses a unique biosystem of microorganisms whose main function is to break down fiber. The small intestine typically digests and absorbs sugar and starch, but in certain cases, such as after the consumption of large grain meals, these can spill over into the hindgut. Microbial breakdown of sugar and starch produce a more acidic environment (known as hindgut acidosis) and, in certain cases, colic.
Fallacy #2: Too much protein makes my horse “hot.”
“When I feed my horse alfalfa or anything with a lot of protein, she gets spooky and is difficult to handle.”
This is by far the most common myth we encounter as equine nutritionists. Lets see if this makes sence to you: A horse consuming a protein-deficient diet might exhibit somewhat dull or subdued behavior. If you then increase the protein level in the diet to the horse’s requirements or beyond, total feed intake also increases. Can the behavioral issues be related to total feed intake, or are they simply a result of going from a deficient diet to one that meets nutritional needs and surpases your riding ability?
Chemically speaking, there isn’t much evidence to explain why protein affects a horse’s behavior in some horses. It is the carbohydrates, particularly sugar and starch (NSC), can affect behavior and metabolism. Researchers have determined that the digestion and absorption of sugar and starch might increase cortisol (the “stress hormone” from the adrenal gland) levels and cause behavioral changes—in some horses more than others. However, protein digestion and absorption does not affect cortisol levels, simply providing the horse with essential amino acids and contributing very little to energy production.
Fallacy #3: Beet pulp must be soaked before feeding, or it will cause a horse to choke or rupture its stomach
“I have heard that feeding beet pulp without soaking it will cause a horse to choke.”
Beet pulp will not cause choke simply on its own. Yes, a horse can experience choke, or esophageal obstruction, when eating beet pulp shreds or pellets, but this is generally a problem that starts with negative mealtime behaviors, such as bolting feed or improper chewing.
Also, there is zero evidence to show that beet pulp will cause your horse’s stomach to rupture. Yes, adding water to beet pulp does cause it to increase in size, but this does not affect what happens in the horse’s stomach. “Over the years, we have not been to find documented cases of a horse’s stomach’s rupturing due to beet pulp,” says Burt Staniar, PhD, associate professor of equine science at Pennsylvania State University, in University Park. In fact, researchers at the University of Kentucky were able to feed up to 55% of the horse’s daily intake as unsoaked beet pulp without any adverse effects—much less stomach ruptures. However, we do prefer to soak the beetpulp first then add the supplements and mixe before feeding.
Fallacy #4: Giving water to a hot horse will cause them to colic.
“Everyone in the horse world knows that a horse will colic if he drinks water when he’s hot and tired after exercise.”
It is vital that any horse performing intense exercise in hot conditions have access to water as often as possible. This is the quickest and best way to replenish fluids and electrolytes lost in sweat. Simply put, waiting for the horse to cool down might exacerbate dehydration.
Like human athletes, after strenuous exercise a horse must be allowed to cool down properly. This allows the heart rate, respiratory rate, and body temperature to gradually return to normal and keeps the muscles moving to flush out lactic acid that builds up during very intense exercise. As a former racehorse owner, our horses, steaming after their races or exercise, were given the choice of water as soon as they returned to the shedrow and 100% drank with no ill effects.
Fact also: An inadequte cool-down can cause severe dehydration and coliclike signs in an exhausted horse, as vital electrolytes are depleted through sweat. So, lead to water first then cooldown.
Fallacy #5: Horses have “nutritional wisdom” and will seek out nutrients to meet their needs
“I recently started noticing my horse licking the dirt out in the pasture. Could he be missing important nutrients in his diet?”
Dirt-eating, or geophagia, is a fairly common behavior in both feral and domesticated horses. Researchers observing this behavior in feral horses in 1979 believed they might be licking the soil to increase their salt intake. In a 2001 study in Australia, researchers evaluated soil from 13 sites where horses were eating dirt and found that the samples contained elevated levels of iron and copper compared to paired control samples, and even horses offered supplemental mineral mixes or feed were among the study group.
The truth is we don’t know exactly why horses lick dirt, but it does appear that they exhibit this behavior even when their diet adequately meets their nutrient needs. This studies did not include mircobes, probiotics or enzymes in the diets and it may verywell may have been the reason for dirt-tasting. This is clearly a guess on our part and in no way to be fact at this point.
One way to potentially curb geophagia is by offering free-choice good-quality forage at all times. Use small-hole haynets or other feeders to help extend mealtime, leaving less time for boredom (another theorized reason for geophagia) and potential dirt-tasting.