By Dr. Wendy Pearson, Ph.D. (Dr. of veterinary toxicology)

Anyone out there remember the typewriter? You know, that noisy mechanical gadget that slowly tapped out letters on a piece of paper. This relic of communication technology was really a remarkable invention, but hands-up everyone who is glad we don’t have to use it anymore!

Now consider the old faithful hoof care product. Most of us remember when biotin was the only thing we had to feed our horses to make us think we were looking after their hoof needs. How times have changed! Good science mixed with good sense has crafted a whole new generation of nutritional hoof care products. 

This shift in thinking has been spurred by a growingly inclusive approach to rebuilding hooves. Far from being just four lumps of biotin on the end of a horse’s legs, hooves are made up mostly of protein (around 93 percent, especially methionine and cysteine), B-vitamins (including biotin, choline and inositol), and minerals (including zinc, copper and calcium). Back in the day, hoof care supplements only needed to contain biotin to make us believe we were taking care of hoof needs, and this is not entirely unfounded — some good research in the late 1990s demonstrated that you could accelerate hoof growth by up to 15 percent by feeding supplementary biotin. The problem is that as soon as biotin supplementation stops, around 70 percent of hooves return to their pre-supplementation brittleness and poor structure. So clearly the biochemical complexity of equine hooves goes beyond just feeding extra biotin.

Inclusion of amino acids in a hoof care supplement is critical, particularly considering hooves contain primarily protein. The limiting amino acids in hoof growth and structure are cysteine (located mainly in cells called keratinocytes, which manufacture hoof tissue) and methionine (located mainly in the stratum basale and in the stratum spinosum of the matrix – see Figure 1). 

While there is little research describing effects of methionine supplementation on equine hoof growth, a series of studies in the 1980s demonstrated significant hoof growth in dairy cows fed a diet containing supplementary methionine. It is interesting that methionine can be biochemically converted to cysteine by the horse, and both amino acids appear to play critical roles in hoof tissue structure. 

The final major piece in the puzzle of good hoof care is minerals, particularly zinc, copper and calcium. A diet deficient in copper and zinc results in poor hoof wall structure, and calcium is also reported to prevent sloughing of cells that make the hoof matrix (an effect that biotin did not have). A great way to increase calcium levels in a horse’s diet is to add alfalfa pellets or meal.

Like many things in contemporary horse management, conscientious care of hooves is not as simple as it used to be. An increased knowledge and awareness of hoof biochemistry and structure has perhaps convoluted our thinking about what’s best for optimizing form and function. But just as we have evolved from the humble typewriter to the super-awesome iPad, our elevated understanding can lead to better overall hoof care for our equine friends. 

More by Wendy Pearson

Main photo: Thinkstock/Quentinjlang