Download Specific nutrient needs of the racehorse

horse health
Words: Dr Caroline E. Foote, Equine Consulting Services
Specific nutrient needs of
the racehorse
EQS’ PRIMARY CONCERN IS ENSURING RATIONS ARE BALANCED, PROVIDING AN ADEQUATE LEVEL OF
ENERGY REQUIRED FOR OPTIMAL PERFORMANCE
While an appropriate balance of all vitamins
and minerals is essential for optimal horse
performance, certain nutrients are more
likely to be deficient than others under
specific circumstances.
Our research indicates that for the
racehorse, energy intake is often the major
limiting factor to performance.
The key electrolytes sodium and chloride
as well as vitamin E and the B Complex
are also more likely to be lower than
recommended compared to other nutrients
analysed. This is most often due to a poor
availability of these nutrients in common
feed sources and heavy losses of some of
these nutrients in sweat.
WHAT DO THESE NUTRIENTS
DO AND WHY ARE THEY
SO IMPORTANT FOR THE
RACEHORSE?
Energy is “fuel” which allows the
horse to optimise its performance. While
the amount of energy needed by the
individual horse will vary according to the
horse’s bodyweight and workload, for
the racehorse energy requirements are
high (over twice that required by a resting
horse). We have seen huge improvements
in individual horses and racing stables as
a whole when energy levels are improved,
often achieved through selection of high
quality feeds.
The grains oats, corn and barley are good
energy sources, as is oil which provides
about two and a half times as much energy
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as oats on an equal weight basis.
There are several performance benefits to
feeding oil in the diet including improved
speed and reduced fatigue but more than
anything oil is a great way of increasing the
energy level of the ration without increasing
the amount of bulk needing to be offered.
Most of the feed companies have blends
of oils available; alternatively canola oil is
generally suitable in its pure form. Oil should
however be introduced gradually into a diet
to avoid changes in faecal consistency.
Sodium & Chloride are essential
nutrients for normal growth and are also
the key electrolytes in all performance
animals. They are also critically involved
in normal nerve and muscle function, and
carbohydrate digestion. Extended work,
in hot dry weather, by a 450-500kg horse
may yield losses of as much as 80g sodium
and 149g chloride.
electrolyte deficits cannot be prevented by
giving them before they are lost.
However, severe deficits can be prevented
by replacing them as they are lost. Water,
should be always available for the horse to
consume as much, as often, and whenever
it wants. Additionally, the provision of
supplemental electrolytes will assist
in reducing the risk of heat stress and
dehydration.
Vitamin E serves as a major component of
the antioxidant defence mechanism. It also
serves to enhance the immune system; is
essential for cellular respiration; is involved
in DNA synthesis; acts as a cofactor in the
synthesis of vitamin C; reduces signs of zinc
deficiency; has a protective function against
the harmful effects of lead, mercury and
silver; decreases platelet aggregation; and
enhances vitamin A absorption and storage.
The loss of sodium, for example, represents
over 200g of salt which is much more
than a horse would eat in a day. A sodium
and chloride deficiency can result in a
decreased appetite, reduced water intake,
dehydration and under severe conditions
may lead to loss of co-ordination and even
collapse.
Lower tissue vitamin E levels not only
increase the risk of exercise-induced
muscle damage but may also decrease
performance. Green growing forage
contains good levels of vitamin E but
grains and hay/chaff contain poor levels
and according to recommended levels of
vitamin E, supplementation for all horses is
required except those on adequate pasture
during plant growth.
In contrast to many nutrients, there are no
body stores of water or electrolytes other
than those carried in the gastrointestinal
tract. Any excess absorbed is rapidly
excreted in the urine. Thus, body water and
B Group vitamins play a role in
the release of energy, and are needed
for numerous essential body functions.
Symptoms of deficiencies of B Group
vitamins include loss of appetite, abnormal
heart beat, muscle tremors, loss of coordination, stiffness in limbs and lung fluid
build-up.
In diets consisting largely of cereal grains,
protein meals, chaff and dried hays, natural
forms of B Group vitamins are generally in
short supply. Injections do not elevate blood
levels for very long and supplementation is
best given in the feed.
Diet-wise, minerals and vitamins should be
regarded as a group rather than individually.
As the intake of a mineral increases above
that needed, the amount absorbed and/
or excreted in the urine and/or faeces also
increases. An excess amount absorbed
may be harmful.
That not absorbed may bind other minerals,
decreasing their absorption and possibly
resulting in a deficiency of these minerals.
It is the balanced amount of all minerals in
the diet that is important. Indiscriminately
adding one or even several minerals to
the diet is likely to be more harmful than
beneficial. Therefore, minerals should not
be added to the diet unless it is known
which ones and how much are needed.
Most feeds contain some minerals and
vitamins but whether these feeds contain
enough will be determined by the level
of activity of the horse. The majority of
trainers in our analyses used commercially
prepared feeds either alone or in
conjunction with grains and supplements.
Despite the high use of these ‘complete
feeds’ over 80% of rations were low
in at least one nutrient. Of all rations
analysed, nearly 70% contained less
sodium than recommended while 30%
of diets contained less vitamin E than
recommended.
At least one B Group vitamin was lower
than recommended in about 75% of diets.
Other nutrients of concern were calcium,
phosphorus, copper and zinc.
Equine Consulting Services is an
independent nutritional consultancy and
offers dietary evaluation and formulation for
racing stables Australia-wide. Our primary
concern is ensuring rations are balanced,
providing an adequate level of energy
required for optimal performance.
Rations are formulated according to
requirement data published in the latest
scientific literature and may be based on
mixing grains and supplements or using
commercially prepared feeds. Please
contact us today to further discuss your
needs.
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