Technical Issues: Hoof Growth promotion for Horses
Hoof growth and regeneration is very much an “inside out” process. The
hoof must receive nutrients from the blood in order to stimulate growth
and repair. Like every other part of a horse’s body, the hoof is a
living structure which depends on the nutrients provided through the
blood for its growth, strength and repair.
Painting anything onto the outside of the hoof won’t improve
regeneration: in fact, modern research confirms that many hoof dressings
actually delay hoof recovery.
How do you get a hoof crack or defect to heal? The simple answer is: You
don’t!
All hoof growth begins at the
Coronary Band. This is the soft band where
the hair meets the hoof wall. If a crack or other defect occurs in the
horse’s foot, the only way for that defect to repair is to wait for new
hoof wall growth from the Coronary Band.
Many factors influence the quality of the hoof:
Genetics
Environment
Farriery
Nutrition
The horse’s hoof quality is affected
by all nutritional components including protein, fat, carbohydrates,
vitamins and minerals. Balancing these components is vital for overall
hoof health and function.
Providing all of the essential nutrients for hoof keratin repair is the
only way to encourage healthy hoof repair and maintenance.
The hoof wall is primarily keratin, an insoluble protein similar to
hair. As tough as the hoof may seem, it is about 95% protein.
It is generally accepted that the rate of growth of new hoof wall is
roughly 1cm monthly, if the horse is on good nutrition. That equates to
over one year for a totally new hoof wall to develop, so that old cracks
and defects grow out. If the toe has a crack, it will take many months
for that crack to grow out. There are no products or supplements that
will help this process speed up. Ponies usually develop a thicker,
stronger hoof than large horses, but it can take up to 20 months to
fully replace the length of a pony’s hoof.
There is a word of caution here: if the cause of the problem is not
addressed and corrected, the problem will continue. If the injury is not
managed well by a farrier during this repair process to prevent further
hoof damage, then repair may not occur as well as anticipated.
Biotin, plus the essential cofactors to ensure
that hoof growth is sound and complete, and provides a sufficiently
strong hoof wall for optimum future growth.
Supplementing Hoof Growth
Numerous studies have been conducted on supplementing various vitamins,
minerals and amino acids to improve hoof quality and rate of hoof
replacement. The two most widely accepted supplements for hoof
improvement are biotin and dl-methionine.
Biotin is a B vitamin. Like all B vitamins, Biotin is water soluble, and
not stored in the body. It must be taken in on a daily basis. Biotin
comes from the diet in varying amounts, and some is produced by natural
bacteria in the large intestine of the horse. The large intestinal
microbial population produces some biotin, but there is very little, if
any, absorption of biotin from the large intestine, and, more
importantly, if horses are on a high grain diet, the production of
biotin may not even occur because of the high levels of acid in the gut
from the grain diet.
Biotin acts as an essential cofactor in many of the body’s enzyme
reactions, and is essential for the production of fatty acids, glycogen
and protein, as well for skin integrity and health, and hoof quality.
A deficiency of biotin will usually show as dry, brittle, cracking
hooves, dishing and low heels, and even just tender feet.
Biotin is the primary rate limiting nutrient for adequate hoof growth,
repair and quality.
The availability of biotin from most cereal products is very low, and it
may be completely unavailable. The exception is maize (Corn), where the
biotin is fully available.
Research Trials on Biotin in Horses:
Biotin supplementation on the white Lipizzaner stallions of Austria over
2 years, ending in 1991,was undertaken because the hoof quality of these
famous horses had deteriorated badly, with crumbling walls, a soft and
wide white line area, and thin, cracked soles. For over 2 years, 26
stallions received daily biotin, while 16 horses received a placebo.
Hoof quality began to improve after 9 months in the supplemented horses,
when a lessening of the hoof cracks and less crumbling of the hoof horn
was obvious. Improvement in hoof condition continued through the
remainder of the study for the supplemented horses, while the placebo
group remained unchanged. Overall improvements in the Spanish Riding
School study were seen as;
Less cracking and splitting of horn, especially at the weight bearing
border
More even surface at the coronary band
Improved white line region
Greater tensile strength of horn tissue
Fewer horn defects under microscopic examination of horn.
The first improvements were evident within 6 months of biotin
supplementation, but the improved hoof condition continued over the next
three years as long as supplementation was continued.
The authors recommended that continuous dietary supplementation of
biotin is indicated to improve and maintain hoof horn quality in horses
with less than optimum quality hoof.
(Josseck, H., Zenker, W., geyer, H. Hoof horn abnormalities in
Lippizaner horses and the effect of dietary biotin on macroscopic
aspects of hoof horn quality. Equine Vet J. 1995 May;27(3):175-182)
Black et al, 1985, examined the hooves of 85 horses, all supplemented
with biotin for at least one year, and compared them to 9 control horses
with no supplementation. They found that supplemented horses showed
better appearance of new horn near the coronary band after 3-6 months of
supplementation, and had significant improvement at the weight bearing
border 8-15 months after the start of biotin supplementation.
The effect of dietary biotin supplementation on growth and growth rate
of the hooves of 8 match-paired ponies was investigated in 1998 by
Reilly et al, who observed that biotin supplementation produced a
significantly higher growth rate of hoof horn, with treated horses
showing a 15% increased growth rate of hoof horn, and 15% more hoof
growth to controls after 5 months of supplementation with biotin
(Reilly, J.D., Cottrell, D.F., martin, R.J., Cuddeford, D.J. Effect of
supplementary dietary biotin on hoof growth rate in ponies: a controlled
trial. Equine Vet J. Suppl. 1998 Sep;(26):51-57)
Geyer etal (1994) conducted a long term study to determine the influence
of daily dietary biotin in horses with brittle hoof horn and chipped
hooves, using 97 horses over a 6 year period. The hoof horn condition of
the supplemented horses improved after 8-15 months as determined by
microscopic findings. The growth rate of coronary horn was similar in
supplemented and non-supplemented horses. The hoof horn condition
deteriorated significantly in 70% of horses after biotin supplementation
ceased. The authors concluded that biotin should be continuously
supplemented at the full dosage in horses with severe hoof horn
alterations.
(Geyer, H., Schulze, J. the long-term influence of biotin
supplementation on hoof horn quality in horses. Schweiz. Arch.
Tierheilkd. 1994; 136(4):137-149)
Buffa et al (1992) over a 10 month period examined 24 riding horses fed
with biotin. Statistically significant improvements in
growth rates and
hardness of hooves were produced by biotin supplements. Greater growth
rates and hardness were achieved at a daily dose of 15mg than at lower
doses. Increased hoof hardness was greatest in hoof quarters and toes.
(Buffa, E.A., van Den Berg, S.S., Verstraete, F.J., Swart, N.G. Effect
of dietary biotin supplement on equine hoof horn growth rate and
hardness. Equine Vet J. 1992 Nov;24(6):472-474)
Kempson, 1987, found that two types of defect were observed in
horses
with brittle feet under electron microscope view. The first defect
showed a loss of structure and horn, remedied after biotin
supplementation. The second defect showed poor attachment of the horn
which failed to respond to biotin alone, and required biotin plus
calcium.
(Kempson, S.A. Scanning electron microscope observations of hoof horn
from horses with brittle feet. Vet. Rec. 1987 Jun;120(24):568-570)
This final article made it clear that many horses with brittle, poor
quality horn did not respond to biotin supplementation alone, but did
show a dramatic improvement in hoof horn quality when the diets were
also balanced for available calcium. The traditional diet of oats, bran
and hays contains low levels of calcium and high levels of phosphate as
phytate, which blocks the absorption of calcium in the small intestine,
reducing availability to the horse. The message here is to take care to
provide a balanced ration when treating any nutritional problem. If
owners are concerned about the quality of the diet, they may take
advantage of the Ranvet Free Diet Analysis to be fully advised on the
nutritional value of the horse’s diet while supplementing for something
as important as hoof growth and strength.
Need For Balanced Calcium : Phosphorus ratio in Diet
Many trials have confirmed that a diet adjustment to improve the calcium
: phosphorus ratio can produce a dramatic change in appearance of the
hoof horn within 3-4 months.
One of the best ways to improve calcium : phosphorus levels in the diet
is to omit bran completely, reduce the grain component in the diet, and
replace it with lucerne. British trials show that over a 9 month period,
horses receiving lucerne rather than grain produced 22-25% more horn, of
better structural quality than the control horses on high grain diets.
Poor quality hoof horn makes the horse prone to bruising of the foot.
This mechanical trauma causes inflammation of the coria (structures
inside the hoof wall), and disrupts the process of keratinisation,
leading to poor quality horn. Properly balanced nutritional supplements
can stop this deterioration cycle and stimulate the growth of good
quality horn to protect the underlying tissues.
Like calcium and phosphorus, all other nutritional elements need to be
properly balanced in order for biotin to work effectively to improve
hoof quality. Adequate, healthy hoof wall growth also requires
methionine, zinc, sulphur and copper. The problem is that excess
methionine, for example, will decrease the absorption of copper and
zinc.
Zinc
A deficiency of zinc will result in a defect of the horn where the
keratinisation of the horn is incomplete. Supplementation of zinc will
reverse this effect. Zinc is essential in the normal keratinisation of
the hoof. Zinc often has reduced availability when high calcium levels
are found in the diet.
Sulphur
The protein structure of the hoof contains large amounts of sulphur
containing amino acids, with methionine and cysteine being the two most
important. Cysteine is manufactured from methionine, and both amino
acids may be marginal or deficient in normal diets when accelerated hoof
growth is occurring. Sulphur is also a component of the vitamins biotin
and thiamine, and of chondroitin sulfate (a component of cartilage,
bone, tendons, and blood vessels). The concentration of sulphur
containing amino acids is highest in hoof and hair, which contain the
protein keratin (which is 4% sulphur). Keratin is necessary for the
maintenance of skin, hair and hoof integrity, giving strength and
hardness to these protein tissues.
Methionine is necessary for the production of keratin, and is also a
major source of non protein nitrogen, essential for optimum growth and
nitrogen balance, and one of the major nutrients necessary in the
production of premium quality hoof tissues.
Gelatin
Gelatin is defined as a ‘product obtained from partial hydrolysis of
collagen derived from natural sources such as skin, connective tissue
and bones of animals”. It is an easily digestible protein that contains
all of the essential amino acids except tryptophan.
Hoof growth is slowest when the temperature is particularly hot or cold,
and spring is the best time for optimal hoof growth in temperature
extreme climates. It is vital that all essential nutrients be available
by supplementation to meet the increased growth rates at the optimal
time of year. Any deficiency of nutrients at the time of maximum hoof
growth will result in deficient quality hoof horn growth.
A good hoof food makes sure all essential nutrients for hoof growth are
present and available, irrespective of the diet or season, to be used as
required to provide balanced nutritional supplementation for optimum
hoof quality over the long term.
Summary
Hoof wall growth commences at the
coronary band, and new hoof grows down
from this level, taking up to 12 months for completely new hoof growth
to replace old damaged tissue. There is no way to heal existing cracks
or damage.
A good hoof food provides Biotin, Sulphur, Methionine, Choline,
Magnesium and Zinc – all essential cofactors in the provision of healthy
hoof wall structures.
It is vital that balanced nutrition be provided to any horse with dry,
brittle or cracked hooves, in conjunction with a good hoof food, to
ensure the provision of adequate essential nutrients for hoof repair and
maintenance. Pay particular attention to providing an adequate calcium :
phosphorus ratio in the diet, and reduce grain or bran components of the
diet, while increasing access to green lucerne or hay.
Competent farriery is critical to maintaining healthy hoof wall
structure.