Protein is arguably the most misunderstood essential nutrient in the equine diet. Protein is made up of amino acids, and its main function is in muscle, tendon, and ligament development and repair. But, how do protein needs change in the equine athlete? Here are three key points to remember about protein's role in fueling the sport horse.
Energy
An equine athlete's energy requirements depend on his activity level. The most common forms of energy in the horse's diet are carbohydrates and fats, which are provided via forage and grains or concentrates. Energy from carbohydrates and fats is easily digestible for horses and doesn't require excessive amounts of further energy from the horse's body to digest.
While protein, too, is an energy source for the horse, it's less efficient than carbohydrates and fats. The horse's body uses more energy to break down protein for energy than it does to break down carbohydrates and fats. In addition, this process produces more heat when compared to using carbohydrates and fats. Because of the amount of heat produced by the breakdown of excess protein for energy, avoid feeding a high-protein diet, especially in warm weather.
Sweat
Sweat is an important mechanism for thermoregulation in performance horses. Horses produce heat (which raises their body temperature) when they use energy for exercise. In response, horses will sweat to decrease their body temperature. The horse's sweat is comprised of water, sodium, chloride, calcium, potassium, and a small amount of proteins. These proteins promote the rapid movement of sweat water from the skin, through the dense pelt, and to the surface for heat dissipation.
Researchers currently believe protein loss via sweat to be minimal, and therefore, no additional protein in the diet is necessary unless the horse is severely dehydrated.
Muscle Repair
Protein is necessary for muscle building and repair. During exercise horses experience a breakdown of muscle tissue for energy production and a decrease in muscle protein synthesis. After exercise, protein synthesis in muscles increases to repair muscle mass damaged during performance. Without adequate protein, damaged tissues aren't repaired fully.
Limited research has indicated that the importance lies in feeding the horse a high-quality, balanced protein source prior to exercise, as muscle tissue recovery post-exercise depends on pre-exercise protein status.
Take-Home Message
Protein is important for muscle and tissue synthesis in the performance horse. A performance horse's protein requirements should be met with a properly balanced diet that includes a high-quality protein source.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.