The hooves and hair coat of the horse, similar to our own nails and hair, are largely made up of the protein keratin. In effort to support hoof and hair health, it is important that the nutrients that contribute to keratin synthesis are in adequate amounts in your horse’s diet. If there is a deficiency – you are seeing dull coats and/or crumbly hooves – what might you supplement to toughen the hooves and add shine?
Keratin is Crutial for Healthy Hooves & Hair
The type of keratin found in hoofs and hair is called -keratin, and because it is a protein, it is made up of many amino acids. (Recall that protein is a chain of amino acids, similar to letters making up words. There are only about 20 amino acids, but these can be arranged in numerous ways with potentially thousands of amino acids to make up all of the different kinds of protein). The major amino acids found in keratin are cysteine, alanine, leucine and arginine. Chains of these amino acids tend to arrange in paired coils, held together by sulfur bonds. Many of these pairs together form intermediate filaments, the basic structure of -keratin, and these align together to form keratin matrices, which are embedded within an intracellular cementing substance. Once a keratinocyte (keratin synthesizing cell) is “full” of these keratin matrices, the cell dies and becomes ‘cornified’ – developed into tough protective structures. It is this cornified keratin that is the main component of hair and hooves.
To support keratin synthesis, the horse must have sufficient cysteine, alanine, leucine and arginine. Alanine is considered a “non-essential” amino acid for horses, in that it does not need to be provided for in the diet, because horses have the ability to make alanine in the liver. Leucine and arginine are essential amino acids and should be provided for in the diet, though arginine can also be made from glutamine, another amino acid. Both leucine and arginine are also relatively plentiful in an equine diet that contains whole grains and/or soybean meal. Cysteine is considered a semi-essential amino acid, as it can be synthesized from another amino acid, methionine, provided that methionine is present in sufficient amounts. Both these amino acids are unique in that they both contain the mineral sulfur, which ultimately leads to the bonds between keratin chains. The best natural sources of methionine (and thus cysteine) that can be fed to horses are whey protein and/or fishmeal. Synthesized dl-methionine is also commonly added to commercial horse feeds.