Question
Is there any risk to feeding a young horse a senior or complete feed?
Answer
Feeding a young, growing horse a product intended for a mature horse can be problematic.
Senior feeds are formulated for the requirements of mature adults, not growing horses. Although the young horse’s energy requirements can be met with a senior or complete feed, protein requirements might suffer. Proteins are comprised of amino acids, and one amino acid that is particularly important for growth is lysine. In fact, insufficient lysine in the diet can keep a young horse from growing to its genetic potential. This is why lysine is sometimes referred to as the first limiting amino acid for growth in young horses. Most feeds intended for mature horses do not contain adequate lysine. On the flip side, high-quality feeds formulated for young horses generally have enough lysine to fuel growth. In addition to protein quality (i.e., amino acid composition), the amount of protein in feeds for young horses is greater, and this extra protein is used for the tissue synthesis associated with growth.
Aside from protein, young horses require different amounts of key vitamins and minerals. As with protein, high-quality feeds take these requirements into consideration when formulating feeds for foals, weanlings, and yearlings. Senior and complete feeds are formulated for high intakes because they include roughage to replace some of the hay or pasture in the diet that the senior cannot ingest well. Because of the high recommended intakes, the vitamin and mineral concentration is low. The fact that these types of feeds do not have the correct micronutrient balance for the growing horse compounded with feeding below the recommended amount results in inadequate mineral and vitamin fortification intake, which is doubly important for proper bone development and sound growth.
If you are not interested in using a feed intended specifically for young horses, it is possible to supply all the nutrients necessary for growth through the use of a balancer pellet, which is a concentrated source of protein, minerals, and vitamins. This type of pellet can supplement a senior feed or complete feed and raise the protein and micronutrient fortification levels to where they should be.
Also, a balancer pellet is especially useful in the diets of young horses that are experiencing rapid growth and showing signs of physitis (inflammation of the growth plates and often the cause of swollen joints in young horses). Rapid growth is sometimes caused by the consumption of too many calories. Limiting caloric intake by removing a concentrated feed and adding the correct amount of a balancer pellet can moderate growth while still supplying appropriate nutrition. Of course, good-quality forage should be offered as well, though energy-dense hay (such as alfalfa (lucerne)) might be switched to grass hay.
