The ABCs of Feeding Young Horses

The ABCs of Feeding Young Horses

A balanced diet of amino acids, balanced minerals and controlled starches is key to development in growing horses.

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By Dr. Holly Spooner, PhD, Cargill Animal Nutrition

Whether you’re raising racing, western performance, or hunter prospects, feeding young horses for sound development is crucial to later success. Many horse owners fear rapid growth in youngsters, yet research to date shows no relationship between rate of growth and incidence of developmental disorders when youngsters are fed a balanced diet. And feeding horses on a high plane of nutrition may mean youngsters are better suited to early training or fetch higher sale prices. Fast growth can be safe, healthy, and even profitable. At the same time, though, the digestive system of young horses is not fully developed, particularly in its ability to utilize forage, meaning more of the diet may need to come from concentrate feeds. 

To better understand the feeding of young horses, it can be helpful to start with the ABCs: 

  • Amino acids
  • Balanced minerals
  • Controlled starch

A: Amino Acids

Young horses can reach 60-70% of mature height and weight by one year, and 85-90% by two years of age.  This early rapid growth means horses lay down a great deal of muscle. This is largely made of protein, which, in turn, is composed of amino acids. Amino acids can be considered the building blocks of the protein, with specific amino acids required in a specific combination depending on what protein is being made. If the necessary amino acid is not available, the protein simply cannot be made. In the horse, the amino acid most likely to be “needed yet missing” and therefore termed the “most essential” or first limiting is Lysine. Methionine and Threonine are the next limiting, and consequently also important for inclusion in growing horse feeds. Selecting a feed designed for young, growing horses that contains guaranteed levels of these amino acids, such as SafeChoice® Mare and Foal, is an easy way to ensure they are available for your youngster.  

B: Balanced Minerals

The next building block of feeding young horses is balanced minerals. Many horse owners are aware that horses will require calcium and phosphorus for bone development, but other minerals needing consideration in youngsters include magnesium, copper, zinc, and manganese. Horses will have a requirement for these minerals among others, but further complicating things is that many minerals can compete with one another for absorption. Overfeeding of minerals, then, should be avoided. Contrary to common belief horses do not regulate their own mineral intake well and free choice mineral feeding is not recommended. Minerals should instead be provided as part of the horses feed ration. Mineral form should also be considered, however, when selecting a feed. Complex or organic trace minerals, such as those found in Nutrena feeds, have been shown to be more available to the horse as a result of their unique route of absorption compared to inorganic forms. Feeding your Nutrena® feed according to recommended feeding directions is the easiest way to ensure mineral requirements are being appropriately met.

C: Controlled Starch

The final building block to consider, the “C” of our ABCs, is controlled starch. Sugars and starches are one way that horses receive energy or calories from their feed. In the case of high-performance horses, these sources are needed for quick energy production and subsequent recovery. In the youngster, however, overfeeding of sugars and starches has been implicated in developmental disorders, particularly when other nutrients are deficient. Nutrena was the pioneer of controlled starch in horse feeds and continues to offer controlled starch formulations. Selecting feeds where energy is derived from fats and fibers can provide your youngster adequate calories without unnecessary overfeeding of sugars and starches.  Again, feeding according to feeding instructions is crucial to ensure your horse receives adequate nutrition without excess calories or an imbalance of nutrients. Mixing commercial feeds or “cutting” feeds with oats or other grains can disrupt this important nutrient balance, and in some cases provide an unhealthy overload of sugars and starches.
Understanding a bit more of the ABCs of feeding young horses, it is easy to see that there are many facets to consider when selecting the appropriate feed to offer alongside your quality forage.  Fortunately, the availability of well-tested commercial feeds formulated for young growing horses, such as Nutrena’s SafeChoice® Mare & Foal, can simplify your feeding plan while ensuring your youngster gets the right start regardless of his future career. “What’s Inside Counts®” and you can count on Nutrena to help you meet the needs of your American Quarter Horse throughout his life. 

For more information on feeding young horses, or where to purchase Nutrena® Feed, please visit