Nutrients
Here are some of the classes of nutrients and I am sure that this is
not the first time you have seen this.
The most important nutrient is water, you cannot forget that. The horse
can live for quite a while without any of the other ones, for up to several
weeks really. But they could not live without water for more than three
days and they would have severe problems. From that stand point, even
though water does not supply any energy or any proteins or any vitamins
or anything like that, water itself is still the most important nutrient
in a horse’s diet. It is essential body temperature regulation.
Tt is essential for all enzymatic functions. It is essential for keeping
proper circulation, keeping proper viscosity in the blood and all other
body fluids. A horse needs about 10 to 12 gallons per day, that is for
maintenance, under normal circumstances meaning it is not too hot, the
horse does not really work very hard and it is not sweating very much.
That intake is then greatly affected by air temperature, exercise, whether
or not the horse is lactating and also how much dry matter or how much
hay a horse will eat. In other words, if a horse is really working hard
and the air temperature and the humidity is up over 100, or the heat index
is over 100, that 10 to 12 gallons can go all the way up to 30, 40, sometimes
50 gallons of water. I have seen horses down near College Station, or
Houston, Texas drink up to about 50 gallons of water when they are being
worked hard and the heat index is over 110 degrees.
The next thing is energy. Energy is primarily derived from carbohydrates
and fats and that is probably not news to you either, that is not any
different than any other animal. Energy is also derived from protein.
But protein is not one of the more important ones; protein is third. The
only time protein becomes more important as an energy substrate, is when
the horse eats too much protein for what he needs for muscle building
and growth. In other words, if I have a horse on a straight alfalfa diet
and I do not supply him enough starch in his diet then protein all of
a sudden can switch to the number one energy supplier and that is not
really a good thing. For this deal, protein should be the third. It is
essential for growth, in other words a horse need to have enough protein
in its diet for proper growth. If you were to think of average daily gain
in a growing horse, what would that be? Most of you guys would know what
that is in cattle because it is a pretty important parameter that we look
at when we raise cattle. Most horse people do not have a clue how much
their growing horse gains a day. It will be anywhere from about a pound
to two and a half pounds in the first six months. Two and a half pounds
is really, really pushing them and a pound is pretty much minimal. If
they do not gain a pound, then you are holding them back, you are not
feeding them enough or you are not feeding the mare enough and she is
not producing good enough milk. It is important for muscle development.
And in the grown horse, it is important for reproduction, a lot of the
hormones are protein-based. And it also important for lactation. In other
words, a lactating mare will put about 50% of the protein of her daily
protein intake, straight into the milk. If your mare’s intake is
not sufficient, she will still try to keep the protein up in the milk.
But she will pull on her own muscle tissue and that is not a good situation
either, that can only go on for a limited amount of time. We need protein
in the exercising horse for body tissue repair and for skin and hair development.
Why did I put lysine down there, what is lysine? It is an amino acid and
there are twenty of them, why did I just put that one there? It is the
most important limiting one or first limiting amino acid. In other words,
when you put together a horse ration that is balanced for protein, energy,
fats, minerals and vitamins, all of your amino acids are usually going
to be there except lysine. So you have to analyze your ration, in addition
to everything else, also analyze it for lysine. You may have to add some
extra lysine to the diet in order to balance for it.
Vitamins are very important for lots of different functions, but primarily
are catalysts in energy metabolism. Again, there are two groups, the fat
soluble ones A, D, E and K and the water solubles are the B-complex vitamins
as well as vitamin C. Why do we have the potential for toxicity in A,
D, E and K? On the other hand, why do we not have the potential for toxicity
in the water solubles? Why can you feed too much of the fat solubles?
Basically, they are not being excreted; they are being stored in body
fat. Therefore, they can become toxic. The toxicity level is fairly high.
So you would have to feed a lot of it before it becomes toxic to the horse.
However, if you look at vitamin B or C, you could not feed it enough to
make it toxic because the horse would just expel it in the urine and it
would not be a big deal. By the way, do you put vitamin C in horse’s
diets? Have you ever heard that, that you should put vitamin C to keep
them from getting a cold? No, we do not put vitamin C in the horse’s
diets, they produce it themselves. The only exception to that is, horses
over 25. Horses that are over the age of 25, we actually do put some vitamin
C in their diets and that is one of the differences between Equine Senior
and other horse feeds. Equine Senior has added vitamin C, in order to
compensate for the diminished capability of the horse to produce its own
vitamin C.
Vitamin A, and I am not going to talk about all of the vitamins, but
I am going to talk about vitamin A because that is a really important
one. That a deficiency of vitamin A is visible pretty quickly. It will
cause vision impairment and that is the same in humans too. It will cause
rough, dry skin. Rough, dry skin, that is not a real clear one because
lots of deficiencies cause rough, dry skin. So if a horse if protein deficient,
if it is carb deficient, energy deficient, in general, it will always
cause rough, dry skin. On a test, when it asks for what are the signs
of deficiency for anything and you put rough, dry skin you have an 80%
chance you are going to be correct because that will be one of the, and
brittle hair coat, that will be one of the deficiencies. A toxicity of
vitamin E can cause bone fragility and the reason for that is because
it can interfere with calcium metabolism. If you have too much vitamin
E, you can interfere with calcium metabolism which will cause, not osteoporosis,
but something similar to that. In other words, the bone density will go
down which causes the bone to break a lot more easily.
If we look at the different minerals, we have basically two groups, the
macrominerals or the micro or trace minerals. The four most important
macrominerals are calcium, phosphorus, sodium and chlorine. What is one
of the basic differences, why do we call one a macromineral versus a micromineral?
The main reason that we call one group micro and the other macro is because
of the amounts that are required by the animal. In other words, the macrominerals
are required in a gram range, which is expressed in as a percent in the
diet. The micros are required in a milligram range or a parts per million
range. In other words a lot less, about 1,000 times less. That is the
only difference in classification for us.
If you look at, on the right side there, where it says microminerals,
which one jumps out at you if you are from Western Oregon? Yes, everyone
knows that it is selenium. What is the problem with selenium or what is
the circumstance with selenium in Western Oregon? There are areas within
Western Oregon, specifically the Willamette Valley and the river bottom,
where selenium is deficient in the soil. Therefore, it is going to be
deficient in the hay and a lot of the hays that are grown here in the
Valley. If we know that, we can supplement the horses with some additional
selenium to make up for that. But, the problem is that the selenium deficiency
is not really consistent, there are several areas in Western Oregon that
are not deficient at all. The only way to really know is if you test either
your soil or your hay. That’s the only way to really know. It is
a problem if you feed too much selenium. Generally, it is not recommended
that you feed a selenium supplement. What is recommended is that you feed
a grain that has a 0.6 parts per million of selenium in it. That way you
will cover the horse’s selenium requirement without any additional
supplementation. And if you feed hay that was grown in Eastern Oregon,
you do not have to worry about it at all because there is enough selenium
over there.
Calcium and phosphorus is very important for proper bone development.
The ratio is a very critical issue here and that is we need about a 1.5
to 1.0, calcium to phosphorus, and that is not any different than cattle.
That’s the same in cattle and sheep and others. The range can go
from 1.0:1.0 to 3.0:1.0. All that would be considered normal. What happens
if there is more phosphorus in the diet than calcium? Why is that a problem?
Let us say that the absolute amount of calcium is still enough. It meets
what it normally would require, but all of the sudden you feed something
that makes the phosphorus go up and the calcium stays the same. Why do
we all of the sudden have a calcium deficiency or an artificial calcium
deficiency? The additional phosphorus will bind the calcium in the small
intestine and keep it from getting absorbed. All of a sudden, the digestibility
of the calcium goes way down, even though there is enough calcium in the
diet, the horse can no longer make use of it. That is the problem when
the ration gets screwed up. Here is one of the syndromes called big-head
syndrome if a horse is low in calcium. The reason that it is called big
head is because what you will see in horses is that that their head will
swell. The reason it swells is because the horse will pull calcium out
of the skull to maintain body function and it will replace that calcium
with cartilage that gives the head a bigger appearance. In other words,
that’s a fairly late stage of calcium deficiency and it is a severe
problem for the horse.
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