Adding fat to the
horse’s diet has become increasingly popular
in recent years. Whether it’s top-dressing corn oil, switching
to a fat-added grain mix, or the convenience of “dry” fat
in blended fat supplements, the diets of many horses are being
affected by the fat-feeding craze.
While the benefits of high fat diets for horses have been studied
and realized, researchers and owners are now asking if one type
of fat will offer gre ater health advantages over others. Historically, the source of fat added to horse feeds has been
from oils of vegetable origin, which contain high levels of unsaturated
fatty acids. Although healthier than saturated fats, not all unsaturated
fatty acids are the same. Some have greater potential to enhance,
and others to harm, various biological processes in the body. Similar to humans, horses do require certain fatty acids in their
diet. These essential fatty acids include linoleic acid, belonging
to the omega-6 family, and linolenic acid, which is the parent
of the omega-3 fatty acids. The horse does not have the ability
to synthesize these fatty acids in the body, and therefore relies
on what is supplied in the diet. Once in the body, essential fatty acids are transformed into potent
regulators of vital body processes, including blood clotting, inflammation
and the immune system. In general, omega-6 fatty acids tend to
stimulate blood clotting and inflammation, whereas omega-3 fatty
acids tend to suppress these responses. Although these fatty acids
have seemingly opposing actions, the ratio between omega-3 and
omega-6 fatty acids will modulate the final response. One concern with fat supplementation is
that we may be skewing the natural balance of omega-3 and omega-6
fatty acids the horse’s
body is used to receiving. Hay and pasture forages are low in total
fat content (~2%), but most of this fat is made up of omega-3 fatty
acids. Cereal grains, such as oats or corn, are also naturally
low in fat (~3%), but provide primarily omega-6 fatty acids. Corn
oil, soy oil and rice bran are the most common fat sources added
to horse feeds. Not only are these sources high in total fat content
(25 – 99%), they are also providing most of this fat in the
form of omega-6 fatty acids. Ultimately, a high-fat diet derived
from these omega-6-rich sources may change the proportion omega-3
to omega-6 fatty acids, which could have adverse biological consequences. The equine nutrition program at the University
of Florida is hoping to shed light on the role omega-3 fatty acids
play in the health
of horses. Research in the following areas is currently underway
to determine:
• How omega-3 fatty acid supplementation
might be used to boost the immune system of mature and growing
horses
• If the anti-inflammatory properties of omega-3 fatty acids may
affect endometritis in broodmares
• If omega-3 fatty acids from different sources, including flax and
fish oil, will produce a different respo nse
• The effect of season on the omega-3 fatty acid content of Florida
horse pastures
While the health benefits of omega-3 fatty acid supplementation
have been studied extensively in humans, there is still much work
to be done in horses before reasonable recommendations can be given.
Lori K. Warren, Ph.D, PAS
Assistant Professor, Equine Nutrition
Institute of Food and Animal Agriculture
University of Florida
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