Nutrition and the Equine Foot

Many racehorses and performance horses cannot perform to their potential because they have hoof problems that keep them out of work or reduce performance. The old adage "No hoof - No horse" still applies today and this article examines some of the nutritional issues that impact on the hoof of the horse.

Energy intake affects hoof growth

In evaluating a feeding program when faced with a complaint of bad feet, the first thing to consider is total feed (energy) intake. Meeting energy requirements may be the first and most important step in ensuring hoof growth and integrity.

Energy intake can be expressed as energy balance. A horse is said to be in energy balance when caloric intake equals caloric expenditure and weight gain/loss is zero. In positive energy balance a horse will gain weight; in negative energy balance, the horse will lose weight. Caloric intake has a direct effect on just about every metabolic pathway and physiological function in the body.

There is no reason to keep a horse in negative energy balance for an extended period. Research has proven that hoof wall growth was 50% greater in ponies in positive energy balance than in ponies on restricted diets. Many racehorses are in negative energy balance for prolonged periods, so it's not surprising they have hoof problems.

The hoof wall is mostly protein

Research shows that hoof wall is about 93% protein on a dry matter basis. Because of the composition of the hoof wall, several commercially available hoof supplements contain methionine. But methionine is only one of the amino acids (building blocks) contained in the protein of the hoof, and deficiencies of any essential amino acid can be as detrimental as a deficiency of methionine. Horses in training that are on an oaten chaff and oats diet which supplies poor-quality protein will benefit from extra high-quality protein.

Zinc is important, but so are other minerals

In considering minerals, often too much emphasis is placed on zinc and far too little emphasis on the other minerals necessary for metabolism. Remember, the health of the foot is an extension of the health of the horse and if mineral deficiencies compromise horse health in general, then the health of the foot is going to be negatively impacted as well.

There is justification for looking specifically at zinc when trying to put together the 'hoof healthy' diet. Zinc is involved in the health and integrity of hair, skin and hoof. However, adding zinc to a diet that is already adequate in zinc is not going to automatically result in any dramatic increases in the quality or growth of the hoof.

European research has shown that horses with 'bad feet' have lower blood zinc levels than horses with normal feet. This may be due to individual zinc absorption or retention abnormalities. The form of zinc in the diet does have some relevance for the bad-footed horse as chelated zinc may produce results when inorganic zinc does not work. Chelated zinc contains zinc bound to an amino acid and the zinc is absorbed with the protein, which potentially enhances absorption.

Biotin

Most of the emphasis on nutrition and hoof wall integrity is on the vitamin biotin. It is thought that the normal horse has a biotin requirement of 1-2mg per day. Studies have shown that supplemental biotin at levels of 15-20mg per day has had positive effects on histological characteristics of the hoof wall tissue. However, you do have to be patient as the horse takes 6 to 9 months to grow a new hoof.

Recent research has shown that it takes 6 months for appreciable differences between treated and control horses and 18 months for statistically significant differences. Biotin treatment reduces the incidence and severity of hoof horn defects, increased tensile strength and improved condition of the white line. However, in this experiment it did not increase hoof growth rate. Unfortunately, biotin does not work every for every horse with bad feet.

Combination supplements that incorporate biotin, zinc and methionine work better than straight biotin products. At higher dose rates these products can also be a wonderful coat conditioner and can be used in the recovery from laminitis at dose rates equivalent to 45-50 mg biotin per day. Farriers sometimes report a difference in how the nail goes into the hoof as little as a month after starting treatment. Biotin products are expensive but if you can keep a horse in work longer, reduce hoof related lameness and extend the life of a set of shoes that may make the expenditure worthwhile.

The other B-complex vitamins are especially important in horses that are stressed, growing rapidly or intense training. The primary functions of many of the B-Vitamins are carbohydrate and energy metabolism and formation of red blood cells. There is evidence that adequate amounts of Vitamin A in the diet may be important in promoting normal hoof wall growth. Vitamin A is involved in maintaining epithelial integrity and may have an important role in cell maturation and differentiation in the foot. Vitamin A is present in green grass, hay and supplements so deficiencies are unlikely but can occur in dry conditions or if no supplements are fed for a prolonged time.

The bottom line

Even though most bad feet are a result of genetic and bad mechanics, there is a piece of the riddle that can be solved with good nutrition. Find a reputable feed manufacturer, identify the feed that is designed for the class of horse you are feeding, and feed enough of it to get the desired body condition. Look for feeds that are balanced for macro and micro minerals and have supplemental vitamins. Apart from special feed concentrates, commercial feeds should not be cut with oats as this wrecks the nutrient balance the nutritionist has attempted to achieve.

In addition to a good feed, emphasis should be placed on high-quality hay, e.g. lucerne. Sometimes it is necessary to restrict energy intake in specific diets. In these cases, it is important to make sure requirements for the other nutrients are met. Some people who are feeding performance horses have made up their minds that horses must have oats. Dramatic differences in hoof wall growth have been observed when 1kg per day of a supplement pellet (All-Phase) was added to the oat diet.

If everything is being done from a nutritional and shoeing/trimming standpoint, it is worth a shot to use supplemental biotin, methionine and zinc, e.g. BIO-BLOOM. Unfortunately, there is no quick fix and maintaining a good foot on a horse is a combined result of good farriery, good nutrition, good health care and selecting for horses that genetically have a great foot. It is much easier to concentrate on making sure the basal ration is right than to look for quick fixes in the form of supplements, paints and oils.

Contributors: Dr Peter Huntington

By Kentucky Equine Research - Last updated 8 November 2015