Q: My 10-year-old gelding is extremely quiet. We show in the hunters, but he just seems to lack impulsion and doesn’t react to my cues most days when I ride, whether we’re at home or at a show. We’ve ruled out serious health concerns such as ulcers or musculoskeletal pain. Is there anything I can change in his diet to help with his energy levels?

A: When you have behavioral concerns about your horse, always have your veterinarian examine him to rule out any health issues—as you’ve done—prior to exploring diet changes. Each horse is incredibly unique, their behaviors and personalities can vary widely, and a multitude of factors can influence demeanor, from genetics, health, environment, and training to, of course, nutrition.

Making diet modifications that encourage more rapid energy releases might help improve your horse’s energy levels. A variety of feed types can provide our horses with more energy, including fiber, starchy grains, and fats. The way these feed types are digested and metabolized will determine how they influence the horse’s behavior. While many horse owners avoid any products that could make their horse excitable, there are times when adding feeds that provide a rapid source of energy can be beneficial.

Types of Energy Sources for Horses

Horses commonly consume three types of carbohydrates: hydrolysable, rapidly fermentable, and slowly fermentable. They digest hydrolysable carbohydrates, which include simple sugars and starches, in the foregut. Their digestion leads to an immediate rise in blood glucose and insulin, creating a spike in energy typically occurring 60-90 minutes after the horse eats. 

Grains high in starch, such as corn, barley, wheat, and oats, cause this spike in energy. This type of energy provides quick calories, but doesn’t support sustained endurance in horses. Feed these grains in small quantities to reduce the risk of gastrointestinal issues. If fed in large amounts, they can pass through the foregut rapidly, and the starch will reach the hindgut, causing a drop in the pH that results in microbe death.

Fiber typically comprises most of a horse’s meal because his gastrointestinal tract has evolved to consume fibrous feeds. Common examples of these feeds include hay, pasture, beet pulp, and cubed or pelleted fiber sources. They provide the horse carbohydrates that are mostly fermented in the hindgut. Microbial fermentation produces volatile fatty acids (VFAs), which are gradually released because horses digest fiber slowly. Although fiber serves as a significant calorie source for the horse, it does not result in that same immediate blood glucose spike seen with starchy grains.

Fats and oils can also be a “cool” energy source because they have a slower energy release. If you want to add more rapid energy to your horse’s diet, incorporating a small number of grains can be a good option, but remember that a high-quality forage and a ration balancer should make up the majority of his diet to ensure he receives the fiber and nutrients he needs.

Electrolytes for Energy in Horses

If your horse feels sluggish, he might have an electrolyte imbalance. When a horse receives the appropriate amount of electrolytes in his diet, he takes a longer time to fatigue and recovers faster from exercise. For the average-size horse, owners can feed about 2 tablespoons of loose salt daily. On days the horse sweats more, he might need additional electrolytes to support hydration and fluid balance.

Developing a Feeding Program for Sluggish Horses

When designing a balanced nutrition program to support your gelding’s energy and performance, start by selecting a high-quality forage option. Adding some alfalfa might be a good choice because it would supply him with excellent protein and more calories. Then choose a high-quality source of vitamins and minerals; a ration balancer often works well. However, if the horse struggles to maintain weight, a performance feed could offer the additional calories needed. To boost energy add a grain-based product in small amounts because this will provide quick energy he can rapidly digest.

Take-Home Message

When dealing with behavior concerns such as lethargy, first consult your veterinarian because pain is a common cause of reduced energy and poor performance. Work with a qualified equine nutritionist to ensure your horse receives a balanced diet with adequate calories for his workload. If his basic nutritional requirements are being met, a feed rich in hydrolysable carbohydrates that are rapidly digested might help improve his energy levels. Please note that grain-heavy diets increase the horse’s risk of gastrointestinal issues such as hindgut acidosis, so keep the amounts small and always make diet changes over one to two weeks.