Equine Hoof & Coat Nutrition

by Antony Jones

No Hoof, No Horse

The hoof is the horny part of a horse's foot. The cells underlying the coronary band are where new hoof wall grows from. The hoof wall is a keratinised structure with elastic properties. It is estimated that a horse completely replaces it hoof once every year. Within the hoof there are vertical tubules of horn which flex and absorb concussion, thus reducing wear tear on the bones/ligaments/tendons of the horse.

The hoof can become damaged in various ways, lack of moisture physical trauma may lead to the hoof becoming cracked broken. In these instances it would obviously be helpful to both increase the rate of horn production improve its quality. Can this be effected via a horse's diet? There are many different products that are claimed to help, here I want to consider biotin and any related issues.

Biotin

Biotin is part of the B complex of vitamins that the horse undoubtedly requires. It is a crucial co-factor in several metabolic pathways; particularly i) Protein Energy Metabolism, and ii) hoof keratinisation. This is where the link to hoof quality begins, a deficiency of biotin will, amongst other things, decrease the quality quantity of hoof produced. BUT this does not necessarily indicate that feeding it as a supplement to a horse who is not deficient, will improve said horse's hoof. Research in pigs suggests that there may be an improvement in their horn quality, but this is indecisive for horses. Furthermore, as with any bio-chemical reaction, simply increasing the quantity of one agent is likely to just cause a different agent to become the limiting factor; in other words, a balanced diet is what is crucial.

Methionine

Methionine is an amino acid {a protein building block}, it is considered essential i.e. the horse must be fed it. It is again involved in various parts of the body's chemistry, one such part is in the production of horn for the hoof. In fact there is evidence to show that methionine biotin are linked in some of the same reactions, cf. limiting factors. Methionine is a candidate for deficiency in normally fed horses since it typically only occurs at low levels in many foodstuffs. High quality protein sources such as Dried Skimmed Milk or Fish meal are better natural sources than simple grain herbage. Indeed there may be a case for feeding artificial supplements of methionine after illness, to aid recovery.

Avidin - an anti-vitamin

Avidin is a protein like molecule that effectively destroys biotin by forming a complex with it (illustrated left). Unfortunately avidin is present in eggs, a common pick me up fed to horses. Whilst not criticising the use of eggs as an equine feed {I've fed them myself}, it should be noted that if feeding eggs a biotin supplement, one may be tying up all the additional biotin being fed.

Editorial Comment

There is no substitute for a balanced diet and good farriery. However when considering "Is my horse's diet balanced?" it is worth considering the quality of protein that is being fed the vitamins available and then deducing what supplements may be needed. Feeding of a broad spectrum supplement without considering if it is required at what level each constituent is present; may not be helpful, in fact it may be to some detriment. This said, there is no doubt that biotin methionine supplements do have their place in promoting healthy hooves.