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Equine
Nutrition in the 21st Century, Part Two
By equine nutrition
expert Judy Reynolds, Ph.D., P.A.S.,
Divisional Equine Technical Specialist, ADM Alliance Nutrition |
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What’s best
to feed your horse—oats, pellets, sweet feed?
To read the first installment of Equine
Nutrition in the 21st Century, click here.
All Grains Are Not Created Equal
You love that smell and look of fresh, plump oats, bright yellow
corn and sweet smelling molasses in your feed, and so does your
horse. But, what is in your feed? How will your horse react to
what you feed him every day?
Cereal Grains
Cereal grains are the seeds of plants, which contain plant embryos
and are high in starch, a readily available energy source for
embryos to use until they sprout and begin photosynthesis. Grains
are very palatable to horses and have been used as high-energy
feeds throughout recent history. We know all grains are not
created equal, so let’s compare them (See figure 1).
Figure 1
(Click chart to see enlargement)
Oats
are the traditional cereal grain for horses and are the
best choice for several reasons. Oats are very palatable and are
the best nutrient-balanced grain, containing about 53% starch, 12%
protein, 5% fat and 12% fiber. Most importantly, the starch in
oats is easily digested (83%) by enzymes in the foregut (See
figures 2 and 3). Therefore, oat starch doesn’t contribute to
starch overload in the hindgut like corn and barley starches do.
However, horses fed oats will have increased blood sugar at about
1 1/2 - 3 hours after the meal, followed by decreased blood sugar.
This effect is similar to that seen in people eating high starch
or sugary foods. Some horses are very sensitive to increased blood
sugar, and exhibit a “grain-high” attitude, which can interfere
with your training and performance schedule. Also, oats tend to be
high-priced for the nutrients they provide. Oats should be clean,
but don’t need to be processed, except for horses with poor teeth
(very young, sick or old horses).
Figure 2
(Click chart to see enlargement)
Figure 3
(Click chart to see enlargement)
Corn
sometimes has a bad reputation as a horse feed, for good reasons.
Corn is more energy dense and heavier than oats, so a direct
can-for-can substitution of corn for oats will lead to
overfeeding. Also, corn is not balanced for nutrients, containing
about 71% starch, 8% protein, 4% fat and only 2% fiber. And, worst
of all, most of the starch in corn is not digested in the foregut,
unless the corn is ground and pelleted or extruded. Most of the
starch (72%) from whole or cracked corn is not digested in the
foregut and proceeds to the hindgut where it is rapidly fermented.
That process results in the production of lactic acid, which
lowers the hindgut pH and kills many beneficial fiber-digesting
bacteria. Dying bacteria release toxins, and the result can be a
horse with colic and/or laminitis resulting in founder (See figure
4). For these reasons, corn should be processed for all horses,
and it should not be more than 25% of a pelleted feed. Also, corn
screenings often contain potentially lethal mycotoxins and should
never be used in horse feeds.
Figure 4
(Click chart to see enlargement)
Barley
(65% starch) has a hard kernel that horses cannot easily
chew, so it is usually rolled. However, even in rolled barley, the
starch has a low pre-cecal digestibility (about 21%) in horses.
Therefore, oats are a much better choice for horses than barley.
The take-home message here is that
oats can be fed whole. However, corn should be processed. Barley
isn’t helped much even by processing, making it a poor choice for
horse feed.
Oats, corn and barley are individual
grains. But, what about grain mixes and fortified feeds?
Grain Mixes and Fortified Feeds
Grain mixes contain grains and
molasses, but not added vitamins and minerals. They always contain
more phosphorus than calcium and usually lead to nutrient
deficiencies and imbalances in the total ration.
Fortified feeds are very popular,
because they contain vitamins and minerals in the correct amounts
and ratios for horses. Be sure to check the label. Vitamins and
minerals added to feeds must be listed on the label. If they are
not listed, the feed is a grain mix, not a fortified feed.
Fortified feeds come in two main forms, sweet feeds and pelleted
feeds.
Sweet feeds
come in all formulas, but they usually contain molasses
(4-12%); oats; shelled, cracked or flaked corn (in widely varying
amounts); and, hopefully, a pellet containing vitamins, minerals
and, possibly, protein. Sweet feeds are the number-one choice of
horse owners and horses both, but they are detrimental in several
ways. The molasses is rapidly turned to sugar in the foregut,
contributing to an increase in blood sugar or “sugar high” that
can interfere with performance ability. Also, feeds containing
molasses are eaten more quickly by horses, resulting in lower
digestibility of the feed.
Sweet feeds usually contain a
considerable amount of shelled or cracked corn, and many people
“cut” their bagged feeds by adding corn. Most of this unprocessed
corn is not digested in the foregut, leading to complications in
the hindgut (see Part 1 – The Equine Digestive System). Both of
these scenarios lead to corn-starch entering the hindgut,
something you definitely want to avoid. Also, sweet feeds have a
short shelf life, cake badly in the winter, attract flies in the
summer and are expensive for the nutrients they provide. However,
small amounts of sweet feeds are good carriers for medications and
supplements. And, they might improve the palatability of other
feeds.
Pelleted feeds
also come in many formulas. When made by a reputable company, they
will contain high-quality feeds and by-products from the food
industry. Many components of pellets are more digestible due to
processing. And, pelleted feeds usually have a longer shelf life,
are less messy to handle and are more economical for the nutrients
they provide than sweet feeds. Good-quality pelleted feeds are a
must for horses with poor teeth. Disadvantages of pelleted feeds
are that you cannot see what is in them in order to determine the
kinds of feeds used and the quality of those feeds. This makes it
very important to buy from a reputable company.
Whether you use sweet feed or pelleted
feed, you should choose feed with at least 10% fiber and,
preferably 13-14% fiber. The fiber should be from highly
digestible sources such as soybean hulls, beet pulp or alfalfa,
not indigestible sources like straw or rice hulls. Feeds with
lower fiber are very high in starch, which is less digestible in
the foregut when not eaten with enough fiber, increasing your
horse’s risk of colic.
We’ve discussed the relationship
between grain-starch and digestive disorders like colic and
founder. Other disorders, such as tying-up and gastric ulcers, are
also associated with grain starches. Several forms of tying-up are
the result of horses’ inability to use grain starches for energy.
Horses with those problems do very well on high forage,
fat-supplemented rations. Gastric ulcers are more common in horses
fed large amounts of grain, because: there is not a constant
supply of forage to buffer stomach acids, and, grain starch can
ferment in the stomach, creating additional acid. So, what choices
do we have, besides grains, when our horses need more energy than
forages can provide?
Quick Tips on Feeding
Caution: Starch from unprocessed corn causes
disruption of hindgut environment, which often leads to colic and
founder. Don’t feed more than minimal amounts of unprocessed corn
to horses.
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Pelleted feeds are usually more
nutritious and economical than sweet feeds
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Use fortified feeds rather than
grain mixes
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Choose feeds with at least 12% crude
fiber
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Choose feeds with digestible fibers
like soybean hulls, beet pulp and alfalfa
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Limit concentrates to about 3 pounds
per meal
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Don’t feed more than minimal amounts
of unprocessed (shelled or cracked) corn to horses.
For More
Information e-mail at
AN_EquineHelp@admworld.com
or call toll free 7:30 AM to 4:30 PM
EQUINE
NUTRITION HELPLINE
1-800-680-8254 Central Time
ADM Alliance Nutrition, Inc.
1000 North 30th Street P.O. Box C1 Quincy, IL USA 62305-3155
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