WRANGLING ON THE RANGE #184
FROM "HORSE AND RIDER" - JANUARY 2012
WHAT'S IN YOUR HORSE'S FEED?
A look at some of the raw ingredients that go into the making of
modern commercial feeds.
These days, commercial feeds can contain a lot more than just
alfalfa meal and cereal grains, and looking at feed-tag
ingredients lists can be confusing. We asked equine nutritionist
Clair Thunes, PhD, whose Sacramentobased Summit Equine Nutrition
(summitequine.com) advises clients throughout the U.S. and
Canada, to give us a breakdown of modern feed ingredients. Here's
what she told us.
COMPLEX CARBS.
These are one of the three main sources of energy in horse
feeds. (The other two are nonstructural carbohydrates (simple
carbs/starch] and fats.) Complex carbs, which require bacterial
fermentation in the horse's hindgut in order to be broken down,
typically come from common hays such as alfalfa, grain hay (such
as oat), and grass hay (such as Bermuda), or sometimes from
less-common forages such as soybean hay. Other sources of complex
carbs are highly fermentable "super" fibers such as beet pulp and
soybean hulls. Super fibers provide a greater quantity of
calories than typical forages and are useful where calories are
needed but starch must be limited.
SIMPLE CARBS/STARCH.
These are typically provided by traditional grains such as
barley, corn, and oats, as well as molasses - a customary
ingredient in sweet feeds. Some feed manufacturers may use the
collective term "grain products" on their ingredients list, which
can include any of these grains in various forms plus others such
as wheat and rice.
FATS.
Fat tends to be highly digestible and contains two and a quarter
times more energy than an equal weight of carbohydrate. It also
helps reduce the dustiness of feeds and aids in the absorption of
fat-soluble nutrients, such as vitamin E. Sources of fat include
vegetable, soybean, and corn oils, all of which supply energy
only - no protein or minerals. Rice bran (about 20-percent fat)
is another popular source.
Levels of fat in horse feeds have increased in recent years as
manufacturers have sought to decrease energy from starch. With
the growing awareness of fatty-acid balance in the diet, some
feed companies are moving away from using corn oil as a fat
source (as it's high in omega-6 fatty acids) and relying more on
soybean oil (which has a slightly higher omega-3 count). Some
companies also are beginning to add omega-3 fatty acids from flax
and even fish oil to some of their higher-end products.
One complication of fat in horse feeds is that it makes the
resulting product harder to form into pellets. For this reason,
high-fat feeds are often textured, or a mix of pellets and other
ingredients, such as beet pulp. In these instances, the fat may
be applied to the feed toward the end of processing, which can
cause the feed to look "wet." Traditionally, such an appearance
has been caused by molasses, thus can create concern in the eyes
of buyers trying to avoid simple carbs. So always check the feed
tag to determine if a wet appearance is likely the result of fat
or molasses in the product.
A WORD ABOUT BY-PRODUCTS
By-products, now increasingly common in horse feeds, sometimes
cause concern among horse owners. The term conjures up images of
mill leftovers and waste, but many by-product ingredients are
nutritious and have been accepted for years.
For example, wheat bran, a staple of feed rooms for decades, is a
by-product of wheat-flour processing. Beet pulp, which many horse
owners love to feed, is left over after the sugar is extracted
from sugar beets.
Newer and less-well-understood by-products include wheat mill run
and wheat middlings. These are popular because they "pellet" well
and allow performance diets to maintain a high caloric intake
while reducing starch. Other grains have a starch content that's
often over 45 percent: by contrast, wheat middling and wheat mill
run provide a comparable amount of digestible energy but with a
starch content of only about 25 percent. (Dr. Clai Thunes)
PROTEIN.
Many different sources of protein are found in horse feed, and
they're not all of equal quality. Protein consists of amino
acids, which fall into two types: "essential," which must be
provided in the diet, and "non-essential," which may be created
by the horse's own system. Protein quality is judged by the
proportion of essential amino acids that the protein source
provides. High-quality protein sources include milk proteins
(dried whey) and byproducts of oil production from oil seeds such
as soybeans. All these are high in the essential amino acid
lysine.
Other sources of protein include linseed and canola meals.
Sometimes feed companies add amino acids individually, and you
may see these listed on the tag (for example, l-lysine
monohydrochloride).
MINERALS/VITAMINS.
These are included in commercial feeds to ensure that the
deficiencies and imbalances typically found in the forages
consumed by most horses are corrected. Macrominerals (required in
gram amounts) may include calcium, phosphorus, magnesium, sodium,
potassium, and chloride. Trace minerals (required in milligram
amounts) include copper, iron, zinc, manganese, selenium, and
iodine. Vitamins include A, D, and E, plus several of the B
vitamins. Natural vitamin E (d-alpha tocopherol) is most
absorbable.
DIGESTIVE AIDS.
These ingredients, which aid in the utilization of feed by
supporting the horse's gut-bacteria populations, have become more
common in feeds. They include various enzymes and yeast cultures,
as well as the extracts and products of specific bacterial
populations, such as lactobacillus acidophilus.
OTHER.
These include preservatives (propionic acid), flavorings
(anethose, fenugreek seed, yucca), stabilizers (lecithin), and
pelleting agents (glycerin).
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