Published: April 2021 | Updated: May 2023
Protein and amino acids can be supplemented to horses in many different forms including; pellets, powders, tubs, and more. However, it is important to understand your horse’s protein requirements so you do not accidentally over-supplement.
What Do Amino Acids Do For Horses?
Amino acids are the building blocks of proteins. The horse needs the appropriate amino acids to support tissue growth and repair. Amino acids also play an important role in metabolic processes, such as forming neurotransmitters and maintaining body tissues.
There are 21 different amino acids that build proteins in the body. The horse can synthesize 12 of those on their own. The other 9 need to be provided in the diet .
These 9 amino acids are called “essential amino acids” because it is essential that these be part of the horse’s diet. Good quality hay and feed usually contain these essential amino acids at appropriate levels.
In the horse, lysine, methionine and threonine are the most limited in the diet, therefore they are rate limiting amino acids. These can be supplemented by themselves or provided through common feedstuffs.
If the horse does not have all amino acids working together, then muscle development, hair coat, hoof growth, and other processes will be stunted.
The Best Source of Amino Acids For Horses
Amino acids are provided in the diet in the form of protein. Soybean meal is considered the “ideal” protein source for horses because of the amino acid composition and concentration of lysine, the first limiting amino acid.
The National Research Council (NRC) has defined standard crude protein (CP) requirements for horses. Crude protein means the total amount of protein in the diet. The average CP maintenance requirement for the horse is 1.08-1.44 g/kg BW/d.
The range of CP requirements encompasses pregnant horses, growing horses, exercising horses, and pasture horses.
Horses that are pregnant, lactating, exercising, or growing have additional CP requirements above maintenance. Horses that need additional CP can obtain them through high protein horse feeds and supplements or higher quality forage sources.
Be Cautious of Overusing Protein Supplements For Horses
Too much of anything can be harmful. Over-supplementation of amino acids can cause excess nitrogen waste from horses. If proteins and amino acids are not used in the horse they have to go somewhere.
In this case, excess nitrogen is excreted in the urine as urea. This can have a negative impact on the environment. Nitrogen waste products, such as urea, can build up in a closed barn/stall and cause respiratory issues in the horse.
Another thought is, the more the horse has to metabolize these proteins above its requirements, excess heat is produced. This can be particularly problematic for horses living in hot and humid environments.
As FullBucket’s Equine Nutritionist, Dr. Amanda Bradbery explains it, “Protein is a very expensive ingredient. Excess dietary protein is common in mature horse diets, but intentionally overfeeding can be an unnecessary financial burden. However, excess dietary protein often does not create any health problems for horses unless there are pre-existing kidney conditions.”
In other words, overdoing the “high protein diet for horses” trend is not useful for either your horse or your bank account.
Maximize Your Horse’s Protein Digestion With The Correct Amino Acid Supplementation
Conditionally essential amino acids are produced by the body, but may not be produced in high enough amounts, especially during stress, performance, illness, injury or any other compromising situation.
L-glutamine is especially important because it is the preferred energy source for enterocytes, the cells in the small intestine which absorb nutrients. Without enough glutamine, the cells of the GI tract may not function at their best, which can lead to other chronic conditions.
Providing L-glutamine helps maintain the integrity of the small intestine, optimizing its capacity for nutrient digestion and absorption, and overall gut health.
Glutamine is also crucial for healthy metabolism and muscle recovery.
While feeding excess protein can be a waste, feeding a complete gut health supplement, which includes pre- and probiotics to improve digestion and absorption, as well as L-glutamine can be incredibly useful for performance.
Maximize the efficiency of the feed you give your horse (and therefore your wallet!) by using FullBucket’s equine digestive solutions.