hoof is composed of living tissue that 93% protein. The quality and quantity of amino
acids that the horse consumes will affect hoof growth and hardness. The primary protein in
horse hoof is keratin which contains a large amount of the amino acid cystine. Cystine is
in turn made of 2 cysteine (another type of amino acid) molecules that are connected by a
disulfide (two sulfur atoms) bond. These disulfide bonds make the protein very tough and
hard. You cannot feed cystine directly to the horse because it is indigestible. There is
not an available commercial source of cysteine to add to rations. Instead, methionine is
added to the diet, since it can be converted in the horse's body to cysteine which is then
used to produce cystine keratin in the hoof. A recent study from Germany (Coenen and
Spitzlei, 1996) measured the amount of cystine in the hooves of 63 horses of a variety of
breeds. They reported a linear relationship between hoof horn hardness and the percentage
of cystine in the horses with good quality, intact hooves.
FOCUS HF provides methionine from both DL Methionine and zinc methionine. Both are high bioavailable and well utilized by the equine. Please see SOURCE Products: for Horses, for more information.