The Science Behind Hoof Welfare

In this feature, Han Van De Braak (BSc LicAc MCSP MBAcC), MD of aloe vera equine supplement Aloeride explains about hoof health issues and hoof wall separation syndrome…

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We are approached regularly by owners of RoR Thoroughbreds and Connemaras who have hoof health issues and for Connemaras this often means Hoof Wall Separation Syndrome (HWSS)

Within the Connemara community there are some who believe that HWSS is genetic. Those who do, overlook the science of epigenetics that unequivocally shows that nutrition is crucial for DNA to express itself. How DNA expresses itself affects Messenger RNA (mRNA), the very aspect which determines (in every ribosome of every cell of your horse) the amino acid sequences within the protein that is produced. Keratin (the hoof’s major structural protein) is a strand of these amino acid units with alanine, glycine and cysteine being the primary amino acids in alpha-keratin. (These are considered non-essential amino acids because they can be generated easily, a process which is dependent on mRNA)

The technical bit

Perhaps the easiest way to understand this process is to use the comparison to a light bulb on a dimmer switch. The genome project for instance maps light bulbs with a view to linking disease to whether they are present or not. Epigenetics shows that how bright any lightbulb can shine, depends on the right nutrient(s) for that lightbulb. So your Connemara may well have the right genetic material but, without the right nutrient(s) for DNA expression, ultimately the right amino acid sequences are not going to be built. Connemaras are unlikely to be genetically doomed but they and their TB counterparts are likely to lack the lightbulb nutrients. If (epi) genetics plays any role to start with.

The intake of nutrients

When it comes to feeding for hoof health, there is no difference in feeding for health in general. There are no magical nutrients for hoof health, as ever, what nutrients reach your horse’s cells is the sum of nutrient intake, nutrient uptake, nutrient expenditure and tissue perfusion. At Aloeride we advocate making the host inhospitable and, by helping to generate healthier gut flora, you not only increase the uptake of regular feed nutrients, you also render the gut less hospitable to parasites which shows itself in a lower egg count. The lower the parasitic load, the less nutrients are syphoned away from your horse. When hoof health is compromised there is a tendency to look into B6 or Biotin or Zinc to give you but three examples.

It may be useful to split hoof trouble into being about either innate structural integrity or pathogen-related  implying that the innate defence system is insufficient. In fact 80% of samples from horses with hoof horn lesions and 66.7% of the samples from horses with slightly affected hoof horn contained fungi of the keratinopathogenic group (Vet Rec 2000 Nov 25; 147(22):619-22).

Whether structural defect lets pathogens in or pathogens weaken the structure is a chicken and egg situation. True to say that all moulds need moisture to establish themselves, so your attention should divert to the major fat in the hoof (cholesterol sulphate) that forms the bi-lipid layers, a defence mechanism much like the one I refer to in ‘Safer By Sebum’ when it comes to your horse’s skin.

On the inner side of keratin you’ll find Methionine, which is the most hydrophobic of the amino acids. It is often interacts with the lipid bilayer, so here you see a functional barrier to keep hydration inside and undesirable water from outside being repelled. Methionine metabolism is highly dependent on the availability of B12=Cobalamin, B9=Folic Acid , B6=Pyridoxine and B2=Riboflavin. The conversion of Methionine to Cysteine is an irreversible process, which accounts for the well-known nutritional principle that Cysteine is not a dietary essential amino acid providing adequate Methionine is available and B vitamins fuel the transformation pathway. Methionine is a dietary essential amino acid, regardless of Cysteine availability.  You can see why I mentioned complex interactions between nutrients…  Also its interesting to note that over-supplementation with Methionine actually results in sore feet, intermittent lameness, difficulty in keeping shoes on and crumbling hoof walls. The very thing you tried to solve! Over-supplementation with Cysteine is similarly unwise.

Minerals of importance for hoof health are Calcium, Zinc, Copper, Selenium and Magnesium. Many of them are co factors for enzymes. Note that Selenium is the mineral with the narrowest safety margin between the requirement and toxic levels. Signs of Selenium toxicity include loss of hair, bleeding at the coronary band, lameness, hoof rings and cracks, and separation of hoof walls. Getting the inorganic minerals wrong happens not only through over-supplementation but also in diets high in grain/bran and low in forage (or contain low-quality forage)  as they upset the Calcium:Phosphor ratio (too much Phosphor, too little Calcium). Over-counterbalancing that with Calcium can interfere with the gut absorption of Zinc which is an enzyme cofactor for the formation of keratins and collagen (beyond Zinc’s value for healthy skin and hair).

Then, there is the Copper:Zinc ratio. Too much Zinc inhibits Copper which is a required enzyme co-factor for the formation of the disulfide bonds that make keratin harder/stronger. A much lesser considered but important consideration for the hoof micromineral is Silicon which facilitates the uptake of calcium and phosphorus into developing bone. Silicon also is needed to improve the strength of connective tissues such as tendons, ligaments, and collagen.

The above possibly has you thinking how difficult all this is. The intrinsity of how mother nature creates everything including hooves never fails to mesmerise. So keep to the 80/20 rule, your 20% effort to get 80% of the feet right is ‘stick to basics’. Feed appropriately for the breed, for the age and for the level of work, then add a very broad spectrum herb like organic aloe vera in a meaningful quantity to daily feed. This doesn’t only increase nutrient intake, it increases uptake and together with the feed it increases host resistance to pathogens. There are no magical nutrients for hoof health.

For further information on Aloeride:

www.aloeride.com/horses/hoof-health/