By Suzie Middlebrook BSc | Cavalor Nutrition Specialist
When looking at the athletes of the human world, you can often tell what type of sport an athlete competes in by looking at their diet. A distance runner will generally eat foods high in carbohydrates & fats, such as sweet potatoes, nuts, & bagels with cream cheese. In contrast, a weight lifter would eat a diet high in protein like chicken, tuna, & soy products, with carbohydrates being the primary fuel source, particularly in the form of pre-workouts and energy boosters. But why is that and how does that compare to your horse?
All food energy sources can be measured in calories. By definition, a calorie is the amount of energy needed to increase the temperature of 1 gram of water by 1 degree Celcius. To complicate things, the Calorie that we see on the nutrition labels of products in the grocery store is not a calorie, but a kilocalorie. Upper-case-C “Calorie” and “kilocalorie” are interchangeable and both mean 1000 calories. In terms of food, calories come from three different sources: carbohydrates, fats, and proteins. While carbohydrates and protein both contain approximately 4 Calories per gram, fat is more calorically dense and contains about 9 Calories per gram. While there aren’t “good” calories and “bad” calories, there are “better” calorie sources depending on the type of work you are doing.
If your horse is a barrel racer and needs to explode out of the gate, similar to the quick, powerful movements of a weightlifter or sprinter, then that horse needs a calorie source that can also be broken down & utilized just as quickly. The same could be said for show jumpers, racehorses, and polo ponies. While fats are very energy dense, packing over twice the calories per gram, it takes a relatively long time for the fat-burning engines to warm up – about 30 minutes – and only a certain amount of that energy is available at any given time since fat is slower to break down. Instead, these high energy, short duration type activities are best fueled using carbohydrates.
Carbohydrates have two major benefits in this case: they are stored right at the muscle for rapid use and they are quickly available after eating. The major working muscles contain stores of glycogen, which are chains of glucose or sugar molecules that can be easily broken off and used as needed. These glycogen stores only take seconds to activate, allowing a huge amount of energy to be available to the horse almost instantaneously. Another benefit of carbohydrates is that, from mouth to muscle, it only takes minutes for the body to convert the energy from food to energy being used by a muscle. In comparison, fat takes hours to become available for use after a meal. While there are cases when horse owners should be careful with incorporating high amounts of carbohydrates into a horse’s diet, such as if your horse is prone to laminitis, overweight, or perhaps insulin resistant. However, for high performance horses in barrel racing, show jumping, or other high intensity/high speed sports, there isn’t a better energy source in terms of rapid availability and power.
For longer duration sports, like dressage or endurance racing, we need to feed a blend of carbohydrates and fats to fuel these horses properly. Fats are critical for long-term energy. While carbohydrates are great for short, quick movements, they can be depleted fairly quickly, especially you are not continuously eating foods high in easily digestible carbohydrates during your workout. Fat, in comparison, is essentially an unlimited energy source in the body. As long as you are not burning fuel faster than fat can be broken down and mobilized by the muscles, you can keep going for an almost indefinite amount of time. Another benefit is that fats create less heat. While carbohydrates can be burned quickly, they also create a lot of heat, which can contribute to heat stress over longer exertions. This heat stress can cause a horse to become tired more quickly than they would otherwise. Fats are more efficient while generating less heat and more movement, helping the athlete continue working for longer periods of time.
With this information, we can begin to devise a plan to best feed a horse for the type of work they are performing. For horses that are doing high intensity, short duration work, like show jumping or barrel racing, a feed with a relatively high in nonstructural carbohydrates (NSC’s) in the 25% to 35% range – is more appropriate. NSC’s are carbohydrates that can be rapidly broken down by the horse and may pose an issue for horses that are idle or have some sort of metabolic condition. For hard working horses that are going to be burning through this energy quickly in their day-to-day work, higher NSC levels in the feed allow these horses to have the amount and type of energy source they need to perform at their best. These horses also benefit from having a moderate amount fat in their diet, somewhere around the 3% to 6% range, to make sure they are getting the fat-based nutrients they need, such as vitamin E, vitamin A, and omega fatty acids.
For horses doing long duration, low intensity work, such as endurance horses and dressage horses, a feed higher in fat and a touch lower in NSC levels is more appropriate. These horses often do well on a feed that is around 5% to 10% crude fat. While that may not seem like a lot, remember that fat is much more energy dense than carbohydrates. For example, 7.5% crude fat is the equivalent amount of energy to 17% carbohydrates. These horses still need a significant amount of carbohydrates in their diet to allow them to perform their best. A feed with a NSC level between 20% and 30% is most suitable. The more rigorous the training, the higher the NSC level.
For these hard-working horses, protein is also a crucial part of their diet. A feed that contains between 10% and 12% is more than adequate for most horses assuming that the forage in their diet, such as hay and grass, is high quality and nutritious. The majority of the protein in a horse’s diet should come from their forage. The protein found in the performance feed you choose for your horse should be designed so that it covers the specific amino acid requirements of your horse, such as lysine and methionine. These amino acids are the building blocks of proteins, similar to how letters help make up a word, and help repair and build muscles, tendons, ligaments, and joints. Ensuring that your horse is receiving the proper amount and types of proteins in their diet is crucial to their long-term health and soundness.
We can give our horses the energy and nutrition they need to perform at their best by making sure they are fed appropriately for their workload. By more fully understanding the thought process behind the formulation of different feeds, horse owners are better able to select a performance horse feed that best meets the needs of their horse. As the equestrian community embraces the practices and methods commonly used in the realm of human athletics, we should better be able to understand how to fuel our own equine athletes. These well-fed athletes will then continue on to help us reach our personal competition goals, at whatever level, more easily as better nourished, sounder, and happier competitive partners.
Marlin, David and Kathryn Nankervis. Equine Exercise Physiology. Hong Kong: Blackwell Science LTD, 2002. Print.
About Suzie Middlebrook, BSc | Cavalor Nutrition Specialist
Suzie Middlebrook is a budding equine nutritionist and lifelong equestrian. She graduated from California Polytechnic State University in San Luis Obispo, CA with her bachelor’s degree in animal science where she focused on equine and wildlife nutrition. While there, Suzie was instrumental in a number of feeding trials and experiments that looked at the fiber and mineral digestion in a number of different herbivorous species, including the red panda, the leopard tortoise, and the horse. Her personal project looked into developing an accurate and practical digestion model for the endangered red panda which she presented as an undergraduate at the Association of Zoos and Aquariums/Nutrition Advisory Group conference on Zoo and Wildlife Nutrition in 2011. Suzie loves talking and teaching about the peculiar nuances of equine nutrition and is able to do so as the Nutritional Specialist for Cavalor North America. When not “nerding out” on nutrition, Suzie enjoys competing her two horses in dressage and eventing, trail running, and playing with her boxer dog.