Why are Amino Acids for Horses Important?

In order to fuel, repair, and recover muscle, equine diets must optimally contain a superior amino acid profile, including all 10 of the essential amino acids. Most horse owners can quickly name the crude protein level in the feed they provide their horses. But, what horse owners really need to know about is the amino acid content. Protein is made up of amino acids, similar to how a chain is made up of links. There are two basic categories of amino acids: Essential and nonessential. Essential amino acids must be provided in the diet, as the horse cannot create them on its own in the digestive tract, where the nonessential amino acids can be made. Nutrena products that include Topline Balance help to provide the right kind and ratio of amino acids in each formula.

Another key point is that some amino acids are known as “limiting” amino acids. This means that if a horse runs out of this type of amino acid, it can’t utilize any of the remaining amino acids present in the feed. If the horse has enough of the first most-limiting amino acid, but then runs out of the second most-limiting amino acid, it can’t use the remaining amount of the third most limiting, and so on.

In horses, the first three most-limiting amino acids, in order, are lysine, methionine and threonine. Generally speaking, if these three amino acids are present in sufficient quantities, the ingredients used also provide the remaining amino acids in sufficient quantities. It is increasingly common to see these three amino acids listed on the guaranteed analysis of horse feed tags, as it is an indication of the quality of the protein sources and the balanced nature of the feed.

If you are looking for a feed that may help impact topline, be sure to look at the guaranteed analysis on the feed tag. In specific Nutrena feeds – SafeChoice products, ProForce products, and Empower Balance – the amino acid levels are called out and guaranteed on the tag. The amino acids included in Nutrena’s Topline Balance products are included in specific amounts and ratios. Research has shown that this specific combination and type of amino acids help to support a healthy topline when fed correctly.

Guaranteed amino acids on the tag is a good starting point. You then need to let the horse tell you if the feed is working by regularly evaluating and noting changes in topline condition.

Does My Senior Horse Need Calories or Protein?

hand feeding red sizeThere are some common questions come up when we talk about what happens to horses as they age and why their bodies change shape:

  • Does my good old horse need more calories (energy) or more protein?
  • He is out on good pasture and is holding his weight, but his hair coat looks dull and he has lost muscle mass.
  • She looks a little thin, should I add some fat/oil to her diet?

These are all apparently simple questions, but actually we need to look at the nutrient supply and purpose a little closer.

Calories from fat/oil, digestible fiber (structural carbohydrates and starch & sugar (non-structural carbohydrates) are the key energy sources for horses. If a horse is thin, that tells us that the horse needs more Calories to maintain fat cover measured by Body Condition Score system. Those Calories can be added from extra fat/oil, extra digestible fiber or additional starch and sugar. Vegetable oil contains 2.25 x the Calories per pound of carbohydrates and is a safe way to add Calories. Switching to a highly digestible fiber source (better quality forage, added beet pulp etc.) can also add Calories of digestible energy (DE). It takes 2-3+ pounds of added feed to add 1 pound of gain, depending on the feed.

Adding Calories alone will not bring back the muscle mass. This will require added protein (really added essential amino acids, particularly lysine, methionine and threonine, the first 3 limiting essential amino acids). If a horse is getting adequate crude protein, but the protein is of limited quality and is low in one or more essential amino acids, the horse will not be able to utilize it fully to maintain or restore muscle mass. This is why it is essential to know the quality of the protein in feeds, particularly these first 3 limiting amino acids.

A common situation is an old horse retired to a grass pasture. It may be difficult for the horse to consume enough to maintain body condition, thus the horse loses weight. The grass pasture may also be low in crude protein and certainly low in essential amino acids, so the horse also loses muscle mass. Tough combination for an old friend!

The good news is that this can be reversed with the use of a well-designed senior horse feed providing both Calories and essential amino acids!