© Terri Moore-Cocanougher, MS
published in ANVIL Magazine, April, 1996
HOOF GROWTH RATES
How do you get a hoof crack to heal? Answer: you don't! All hoof growth begins at the coronary border of the hoof. This is the soft band where the hair meets the hoof on the horse's leg. If the horse has a toe crack, it will take months for the new hoof growth to replace the hoof tissue in that present position. There are no products or supplements available which will help a hoof heal itself. There are bonding products and hoof fillers which, when used properly, can improve the appearance of the hoof. A word of caution, however - if the cause of the problem is not addressed and corrected, the problem will continue!
In order to get an idea of how long hoof growth takes in your horse, pay close attention to how much your farrier trims off your horse's hoof and how long it was since your horse's last farrier appointment. That's how long it takes! In horses such as Shires and Lipizzaners the hoof wall grows at about 7 to 9 mm a month. So in 12 to 15 months the whole hoof will have been replaced by new growth. At the other end of the spectrum, ponies generally grow a thicker, stronger hoof, but it may take up to 20 months to replace the length of a pony's hoof.
SUPPLEMENTING HOOF GROWTH
Numerous studies have been conducted recently on supplementing various vitamins, trace minerals and amino acids to improve hoof quality and rate of hoof replacement. The two most widely accepted supplements for hoof improvement are biotin and dl-methionine.
Most likely, you have heard of biotin for hoof supplementation. Did you know that biotin is actually a B-vitamin? Like all B-vitamins, biotin is water soluble. That means it is not stored in body fats. Since it cannot be stored, it must be present in the daily diet. Likewise, since it is not stored, if an excess of biotin is given in the daily diet, the unused portion is cast off in the urine.
There are two sources of biotin in your horse's diet - from their food and from biotin produced by the natural bacteria which aid in digestion. Opportunities for biotin deficiencies in your horse's diet depend on the content of feed ingredients, the natural form in which the biotin occurs and the degree to which your horse can utilize the biotin produced by intestinal bacteria. Since microbial (bacterial) production takes place in the lower part of the digestive tract where little nutrient absorption takes place, not much of this biotin may actually be available to your horse.
Biotin acts as a co-factor in many of the body's enzymatic reactions. It is essential in your horse's body for the production of fatty acids, glycogen production and for the production of proteins. Biotin deficiencies cause skin lesions, sparse hair growth, dry, scaly skin, and brittle, cracking hooves. Hoof deformities such as dishing and low heels have also been associated with biotin deficiencies. Often, horses with these hoof problems show obviously tender feet and will be unwilling to stride out.
CASE HISTORY: The White Horses of Vienna (Josseck, 1991)
Over a number of years, the condition of the hooves of the white Lipizzaner stallions of Vienna, Austria's renowned Spanish Riding School, had deteriorated badly. The horses had crumbling hoof walls, with a soft and wide white line area on the hoof sole. The hoof walls were thin and cracked at the weight-bearing border. Many required shoes to minimize the cracking problem.
Forty-two Lipizzaners were involved in a double-blind study. For more than two years, 26 horses received 20 mg. d-biotin daily in their feed, while 16 horses received a placebo. Hoof conditions began to improve after nine months in the horses receiving the biotin. Improvement was seen as a lessening of hoof cracks and less crumbling of the hoof horn. Improvement in hoof condition scores continued throughout the remainder of the study for the animals receiving supplementation. The placebo group's hoof scores were unchanged throughout the study.
Overall improvements in the Spanish Riding School study were seen in these aspects of hoof condition:
The first improvements were evident within six months of biotin treatment, but the improved hoof condition continued over the next two years, as long as supplementation was continued.
BIOTIN STUDY (Black, 1985)
"The hooves of 85 horses, all supplemented for at least a year, were compared with those of nine control horses. . . . those with significant improvement showed better appearance of the new horn near the coronary band after three to six months of supplementation, and had significant improvement at the weight-bearing border eight to 15 months after the start of biotin supplementation."
"Though biotin is synthesized by intestinal bacteria in the horse, it is not clear how much is actually absorbed there. Green pasture and corn grain are good sources, but cereal grains are considered to be poor sources due to low bioavailability".
DIETARY BIOTIN REQUIREMENTS
One to 2 mg of d-biotin is the optimum recommended dose for normal body functions. The recommended dosage for improvement of hoof health is 20 mg. d-biotin, depending on the horse's body weight.
NEW HOOF HEALTH INFORMATION
Benefits of Zinc Methionine Supplementation
It has long been known that zinc is essential for proper growth and skeletal soundness and has been shown in numerous research studies to improve immunity. Research conducted on the amino acid-specific form of zinc methionine has shown this chemically unique form of zinc methionine to be important in general wound healing, and has shown that it minimizes hoof abscesses and hoof diseases. The amino acid-specific form of zinc methionine also has a much higher absorption rate than other forms of zinc.
University research studies (Moore,1989) have shown Zinpro® zinc methionine provides dramatically improved hoof condition, i.e., hoof texture, reduces number and severity of cracks, and reduces infections associated with cracking in dairy cattle.
A secondary benefit of zinc methionine was detailed in research done by Boon P. Chew, PhD, at Washington State University. Dr. Chew reports, "Zinc can function as a cofactor for the activity of over 100 enzymes." The research study detailed the effects of zinc deficiency on the immune system. So, supplementation with zinc methionine not only improves overall hoof quality, but also benefits by boosting the immune system.
To properly address and correct the problems in a horse's hoof, toe cracks, dishing, white line disease, thrush or any number of common problems, consider supplementing biotin, methionine, and zinc methionine. This logical combination of supplements is designed to facilitate high-quality hoof growth and promote healing.
Black, Angela (1985) Biotin and Equine Structural Soundness. Cook College, Rutgers Univ. Nutrifacts, Hoffman-LaRoche.
Chew, Boon P. (1993) Nutritional Regulation of Immunity. Dept. of Animal Sciences, Washington State Univ. Pullman, WA. Proceedings of 1993 Nutrition Seminars, Zinpro Corporation.
Comben, N., Clark, R.J., Sutherland, D.J.B. (1984) Clinical observations on the response of equine hoof defects to dietary supplementation with biotin.Vet Rec. 115, 642.
Josseck, H. (1991) Huhornveränderungen bei Lipizzanerpferden und ein Behandlungsversuch mit Biotin. Untersuchengen des makroskopischen Hufstatus und des Hornwachstums sowie zum Verlauf des Plasmabiotinspiegels und über genetische Grundlagen der Hufhornschaden. Faculty of Veterinary Science, University of Zurich. Thesis.
Linden, J.E. (1992) The Role of Biotin in Improving the Hoof Condition of Horses, from the series Animal Production Highlights, Hoffman-LaRoche, Ltd., Basel, Switzerland.
Moore, et. al. (1989) Effects of Zinpro® Zinc Methionine on Hoof Growth Rates. Trans. Ill. Acad. Sci. 82:99, Proceedings of 1993 Nutrition Seminars, Zinpro Corporation.
Schulze, J. Scherf, H. (1989) Effects of biotin treatment in horses with poor hoof quality: a clinical study. Proceedings Roche Symposium on Animal Nutrition and Health. Basel, May 1991, p. 124.
Spears, Jerry W. (1993) Interrelationship of Trace Minerals on Immunity and Disease Resistance. Dept. of Animal Science, North Carolina State University. Proceedings of 1993 Nutritional Seminars, Zinpro Corp. ¨
Terri Moore-Cocanougher holds academic degrees in animal science and biology. She is preparing for her PhD in biology.
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