By Lynn Stewart

Hoof care is an integral part of managing your horse’s health.
Many factors can affect hoof quality, including environment, genetics, farrier care, and nutrition. Fortunately, a horse’s nutrition can be easily managed and can have profound effects on hoof strength and structure. The hoof condition of all horses, from young foals to seniors, can be significantly improved simply by ensuring they receive a well-balanced, scientifically sound diet.

As an equine nutritionist, one of the first areas of a horse I evaluate is the hoof quality. The hoof can act as a mirror; its external condition often reflects the horse’s internal nutritional state. Many common hoof problems can be indications of an inadequate diet. The kind of hoof issues observed may help you determine which dietary area is lacking. It is important to note that there is no single magic dietary component that will guarantee good feet; rather, good feet are the result of a balanced diet including adequate protein, energy, vitamins, and minerals.

Protein
The horse’s hoof wall is largely made up of protein. Special building blocks called amino acids link together to form different proteins throughout the body. Some amino acids can be synthesized within the horse’s body; others must be supplied in the diet. The latter are called essential amino acids. Two essential amino acids of key importance to hoof health are lysine and methionine.

Feeding high quality hay is one of the best and easiest ways to ensure that your horse’s diet includes sufficient quantities of essential amino acids such as lysine and methionine, which are important for the growth of healthy hoof tissue. Photo: Robin Duncan Photography

Lysine is the primary “limiting” amino acid (the essential amino acid present in the least amount relative to the need for that amino acid) in most cereal grains, which of course form the basis of the equine diet. When all the lysine supplied in the diet is used up by the horse’s body, protein synthesis stops no matter how many other amino acids are available. Lysine deficiency is common in horses that are fed diets high in cereal grains, and can result in a restriction of growth, not only of hoof tissue, but throughout the entire body, making lysine particularly important for the healthy development of young horses.

Methionine is often the second limiting amino acid, and is unique in that it is a sulfur-containing amino acid. Sulfur is critical to hoof quality because the main protein in hooves, keratin, is very high in sulfur. The sulfur in the keratin forms disulfide bonds which act as strong cross-links binding the fibres in the hoof wall together, and providing the hoof with strength and resilience. If a horse is deficient in sulfur, these bonds cannot form, which may result in poor hoof growth and weak hooves.

The best, and often the easiest, way to ensure your horse receives adequate amounts of essential amino acids is to provide him with high quality hay. Alfalfa-grass blends tend to be a good choice as the protein-rich alfalfa balances against the low protein grass. Unfortunately, there are times when quality hay can be difficult to find. In these situations, it is wise to work with a nutritionist to find an alternate way to supply your horse with lysine and methionine, such as feeding him a commercial supplement.

Energy
Although adequate energy levels are needed throughout your horse’s body, the hoof has special energy needs. Hoof tissue is highly metabolically active, and actually consumes glucose. In particular, the lamellar tissue of the hoof requires glucose in order to be able to act as the “glue” that holds the hoof layers together. With the exception of neglect situations, most horses receive enough energy to support hoof function. More commonly, horses are overweight and consume more calories than their bodies need. Overweight horses can have poor feet, not only due to the additional weight-bearing stress on their feet, but also from metabolic illnesses such as Cushing’s disease or insulin resistance. These can result in high levels of inflammation of the hoof tissue and laminitis. Horses with abnormal metabolisms require very carefully balanced diets.

Flaxseed is an excellent source of the omega-3 fatty acids that are so important for healthy hooves and hair. To obtain maximum nutritional value, grind the flaxseed in a coffee grinder or blender before adding to your horse’s feed.

Fats are also necessary in the diet to maintain the “glue” holding the hoof together, and play a role in keeping the hoof hydrated. Many researchers are currently studying the impact of omega fats on hoof and lameness issues. Omega-3 fatty acids have been shown to improve hair and hoof quality, as well as demonstrate anti-inflammatory properties in horses. The most common omega-3, alpha linolenic acid, is prevalent in fresh pasture grass, fish oils, and flaxseed. Generally I recommend supplementing diets with flaxseed, as pasture is not available year round in Canada, and fish oil is not a common feed ingredient. To obtain the maximum nutritional value, grind the flaxseed with a coffee bean grinder or blender, as whole flaxseed can pass through the horse’s gastrointestinal tract undigested. It is also best to grind the flaxseed right before feeding it, since ground flaxseed that is exposed to the air for longer periods of time can oxidize and become rancid (unless you are purchasing a stabilized commercial product). Generally, a half-cup to one full cup of ground flaxseed per day will provide sufficient omega-3 fats for the average mature horse.

Minerals
Minerals are essential in the diet as they support every biochemical process in the body. Minerals are broken into two groups: macrominerals, which are fed in larger amounts, and microminerals, fed in smaller amounts. 

Calcium is a critical macromineral responsible for many processes including skeletal bone formation, muscle contraction and relaxation, and neural function. Calcium is also necessary to support the enzymatic reaction that produces the disulfide bonds which link the keratin proteins in the hoof. While it is important that your horse consume adequate calcium in terms of grams per day, it is equally important that the calcium level be balanced with the phosphorus level. Calcium should be fed at higher levels than phosphorus, at ratios of 2:1 up to 6:1. Diets in which phosphorus levels are higher than calcium can reduce calcium absorption, which can lead to deficiencies. While calcium deficiencies can cause hoof abnormalities, other symptoms, such as bone fractures or tetany (involuntary muscle cramping and spasm), would probably be noted first. Generally, sufficient calcium can be obtained from good hays, with alfalfa hay being higher in calcium than grass varieties. Additional supplementation may be required if your horse is on a high grain diet (grains are high in phosphorus and low in calcium), or if your horse has higher requirements as do gestating or lactating mares. Calcium can be supplemented by way of commercial complete feeds or vitamin-mineral blends.

A well balanced diet consisting of sufficient protein, energy, vitamins, and minerals can help you build a healthy hoof from the inside out. Photo: Pam MacKenzie Photography

Copper and zinc are two microminerals often associated with healthy hooves. Zinc is necessary for healthy skin, hair, and hooves, while copper increases hoof wall strength. Like calcium and phosphorus, zinc and copper also need to be fed at the correct ratio to one another – usually 3:1 or 4:1 in favour of zinc – to prevent deficiencies.

Zinc and copper deficiencies have been noted in some regions of Western Canada. If you suspect that you are in an area that may have low soil levels, a chemical analysis of your hay and pasture is a good idea. Zinc and copper are usually supplemented adequately in commercial feeds.

Selenium is necessary for the body to produce good, healthy cells. It acts as an antioxidant, and works together with Vitamin E to support the immune system. Large areas of Western Canada’s soils are severely deficient in selenium. Thankfully, most commercial feed companies supplement their products with selenium. However, excess selenium can lead to selenium toxicity, which can cause a variety of hoof problems, including hooves “sloughing off,” severe cracks around the coronary band, and even laminitis.

Unfortunately, the safety margin for selenium is quite narrow compared to other nutrients. Most commercial feeds are formulated to provide adequate selenium when the product is fed appropriately as per the directions. Problems can arise when horses are fed multiple sources of selenium (such as feeding a complete feed and a protein supplement), or when they are fed more than the label recommends.      

Vitamins
Healthy horses can make most of the vitamins their bodies require, with the exception of Vitamins A and E. Vitamin A assists in maintaining the integrity of epithelial cell walls, and is needed for healthy skin and keratin. Beta-carotene (the precursor to vitamin A) is abundant in fresh pasture, but is largely lost in dried and stored hay. Fortunately, horses are able to build up a few months supply of vitamin A in their liver. This, combined with commercial supplementation makes deficiencies rare.

Biotin is a B vitamin that can help strengthen your horse’s hooves and make them less susceptible to damage. Photo: Pam MacKenzie Photography

One of the most commonly used supplements for creating healthy hooves is biotin. Biotin is a B vitamin, and works to improve tissue growth. Although biotin is produced by the bacteria in the horse’s hindgut as it ferments forages, it may not be produced in sufficient amounts or easily absorbed by the horse. For most adult horses, 20 mg of biotin per day is recommended. Studies have shown that with consistent biotin in the diet, hooves are stronger and less susceptible to damage. Horses that are deficient in biotin can have soft white lines and weak hooves that crumble and crack. Biotin products are readily available at most feed stores.

Hooves are built from the inside out, and there is truly no substitute for a well-balanced diet. If your horse’s nutrition is lacking, he will not have the necessary nutrients available to grow healthy hooves. Fortunately, many feed products exist to assist horse owners in preventing nutritional deficiencies. One caution that I cannot stress enough is that, while having too little of a nutrient is bad, having too much can be equally or more harmful. Always pay close attention to the particular supplements your horse is getting, and the amount you are feeding. This is particularly important if you are feeding more than one product. When in doubt, always check with your veterinarian or a qualified nutritionist.

Don’t forget that once your horse is on a solid diet, it takes time for hoof tissue to change and grow. Often it will be six to nine months before changes are noticeable, but taking the time now to evaluate your horse’s diet will have your horse, farrier, and veterinarian thanking you!

Lynn Stewart is a fully certified, independent equine nutritionist, and the founder of Pace Equine Nutrition which offers on-farm and online nutritional consultations, and forage and grain sampling and analysis. For more information about Lynn and Pace Equine Nutrition, visit www.paceequine.com.

Main Article Photo: Christina Handley Photography

This article originally appeared in the August 2012 issue of Canadian Horse Journal.