Question
Tuck is my 18.1-hand (185 cm), 2,400-lb (1,100-kg) Belgian gelding that I compete in pulling competitions. He gets several hours of exercise 5-6 days a week, including both aerobic and anaerobic work. Tuck’s current ration includes free-range hay, and I would guess he’s eating a small bale of hay each day. I feed him an oats-pellet mixture three times a day. The pelleted feed is high in fat and moderate in starch. Tuck’s work requires a lot of strength, and I want to be sure I am feeding him as well as I can.
Answer
Competition pulling horses engage in repetitive sprint-like activity that requires a significant amount of digestible energy (calories) to fuel it. The nature of the activity, near-maximal exertion for very short duration, depends predominantly on internal glucose and glycogen stores. Nutritional goals are therefore based on maximizing glycogen stores (liver and muscle) through supplying sufficient hydrolyzable carbohydrates while maintaining digestive health and function.
Your current concentrate program of 33-50% oats and 33-50% of high-fat pellets is providing the appropriate energy sources for this type of exercise. How much of this mix is Tuck fed per day? It is important to ensure at least 50% of his diet is forage. It sounds like this is the case, as Tuck is being offered nearly one small square hay bale a day. However, do not underestimate the digestible energy contribution high-quality hay can provide. The volatile fatty acids produced during fiber fermentation can be utilized in the production of muscle glycogen. Selecting high-quality grass hay or grass-legume mix can offer the horse a significant number of “safe” calories that also support gut health and function.
Balancing dietary starch levels and digestive health is important. Oats contain moderate starch levels due to the their high-fiber hull, but the starch available is highly digestible when compared to corn starch. Though corn has a significantly higher energy density than oats, it requires additional heat processing, such as steam-rolling, or flaking, to optimize starch digestibility. Processed corn can be a useful addition to the high-performance horse diet, as its higher energy density can allow a reduction in grain intake.
Dietary fat offers several benefits to the performance horse. As a highly digestible energy source, it provides more than twice the amount of digestible energy as cereal grains on an equal weight basis, and after a period of dietary adaptation, high-fat diets may provide a glycogen-sparing effect during lower intensity work, allowing glycogen stores to stay “untapped” until near maximal exertion exercise. To boost fat content without dramatically increasing concentrate intake, you can feed high-fat feedstuffs like stabilized rice bran, flax, and vegetable oil in combination with your current program or as a replacement for a portion of grain or pellet.
It is great that you are offering three meals per day, as this allows you to minimize meal size to reduce the risk of digestive upset, while still providing Tuck with the necessary caloric intake. Meal size should be kept to no more than 0.5% of his body weight.
To simplify your feeding program, you may consider switching to a feed that contains a combination of these energy sources such as a modern race or performance horse feed. These feeds are typically made with energy-dense cereal grains and added fat to provide the necessary calories for high-performance horses.
Hard-keeping horses receiving large amounts of concentrate may benefit from a daily digestive aid. Kentucky Equine Research (KER) developed RiteTrac as a daily maintenance product to support gut health. RiteTrac is an equine-specific antacid formula that also contains a time-released hindgut buffer, called EquiShure, which offers superior protection to the entire digestive tract. Alfalfa is also considered to have dietary antacid properties that can help support gastric health in addition to providing protein and calories. Other beneficial digestive aids include yeast, probiotics, and enzymes to help support a balanced microbial population.
Electrolytes should be given before and after intense exercise and offered proportionally to sweat losses. Electrolyte supplementation can be given on an as-needed basis, but free-choice salt should be available at all times. Proper hydration and electrolyte balance can have a huge impact on performance and recovery. KER has two electrolyte products, Restore SR and Race Recovery, both available as a powder or paste.
Australian horse owners should look for the entire range of research-proven supplements here.
