Protein Supplements for Horses

Horses need protein supplements when their normal diets lack any of the 10 essential amino acids not normally synthesized in their bodies. Protein synthesis in horses requires lysine (most importantly, as this is most lacking in equine diets), as well as valine, tryotophan, arginine, histidine, isoleucine, lysine, leusine, methionine, threonine and phenylalanine.

Horses need protein supplements based on the amount of protein they receive through their diet and if their lifestyles demand a high amount of it. Age is another factor that determines the amount of protein required in a horse's diet. Young horses just weaned from their mothers are likely to need more protein in their diets. Pregnant and lactating horses also have a need for more protein, just because their bodies are supporting the growth and development of their young.

Proteins build and restore body tissues and are the major parts of enzymes, hormones and muscles. They play important roles throughout the body, including supporting the skin, bone, organ, hair and hoof health of horses. Horses may need protein supplements, because protein is important to the structural health of the horse's body and its functions. Eighty percent of a horse's body mass is comprised of protein.

Excess protein is not recommended for horses. It is not processed well within their bodies, and it is an unnecessary expense. Though excess proteins are converted to carbohydrates for energy and urea that is excreted in the urine, this is not a good option for high-endurance horses. Horses will burn more body fat from the heat generated by the excess protein. Some horses can develop hives from excess protein in their diets, which may be an allergic reaction to these foreign proteins. High protein levels are known to cause other ailments, such as contracted tendons and epiphysitis. Balance the horse's entire diet with other vitamins and minerals so the protein is not too dominant.

Several types of protein supplement are available for horses. Linseed oil meal is beneficial for hair coat and muscle function; soybean oil meal has the highest protein content, and is the most affordable type of supplement. However, avoid feeding soybean in its raw form to horses, because it counteracts protein absorption. Other types of protein supplement include cottonseed oil meal, as well as sunflower and canola oil meals. Protein sources used in horse nutrition also include gluten, distiller's grains and brewer's grains.

Protein supplements from animal sources, such as blood meal and meat scraps, are not suitable for equine diets. Horses are naturally vegetarian. Some veterinarians may suggest small quantities of proteins from animal sources, but these animal byproducts are the cause of digestive problems and increased bacterial growth in horse feed.