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Exciting New Health Benefits from Feeding Omega-3 Fatty Acids

Dr. Joe Pagan, Dr. Clarissa Brown-Douglas and Dr Peter Huntington

The benefits of feeding fat as a source of energy to horses are now widely accepted. Fat is scarce in forages and is therefore a seemingly unnatural feedstuff for horses, but its nutritional advantages are now well recognised. Substitution of starch with fat can help relieve painful muscle conditions, modify behavior and help control metabolic conditions. Now that the advantages of fat are accepted almost universally by horsemen, scientists are further exploring how certain fats help horses.

Researchers have focused their attention on two distinct families of fatty acids: the omega-3 family and the omega-6 family. The omega-3 family stems from alpha-linolenic acid (ALA), and the omega-6 family originates from linoleic acid (LA). ALA and LA are considered “essential fatty acids” because they are instrumental in the life cycle, yet they cannot be manufactured in the body and must be obtained from dietary sources.

Significant members of the omega-3 family are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Interestingly, the horse’s body can convert ALA to EPA and DHA when insufficient quantities of ALA are consumed, although this process is not entirely efficient. The lack of EPA and DHA in equine diets is understandable, as these two fatty acids are found almost exclusively in fish. The fish, namely cold-water species, are at the top of a food chain based largely on algae that manufacture EPA and DHA. ALA, on the other hand, is found predominantly in leafy plants. Linseed oil is also a rich source of the short chain omega-3 fatty acid ALA. The primary source of omega-6 fatty acids in the diet is LA derived from the oils of seeds and grains.

The Omega-3 to Omega-6 Ratio: A Balancing Act

Omega-3 and omega-6 fatty acids must be balanced within the body in order for both to be effective. Each fatty acid is necessary for the production and distribution of a class of hormones called prostaglandins. The prostaglandins that evolve from consumption of omega-3 and omega-6 fatty acids have different effects on inflammatory processes in the body. In addition to their effects on inflammatory responses, omega-3 and omega-6 fatty acids aid in the maintenance of cell membrane stability, development and function of central nervous system tissue, oxygen transfer and immune functions.

Scientists have not determined the optimal ratio of omega-3 to omega-6 fatty acids for horses. The natural diet of horses—primarily fresh and dried forages— contains more omega-3 fatty acids than diets consisting of a mixture of forage and cereal grains. Grains possess more omega-6 fatty acids than forages, creating a balance of omega-3 to omega-6 fatty acids that may be inappropriate, especially when diets are high in grain. Horses that must expend high levels of energy—hardworking equine athletes such as racehorses, three-day event horses and polo ponies—are typically fed high-grain diets. Lactating broodmares and yearlings often also fit into this category.

The Benefits of Omega-3 Fatty Acids

Interest in omega-3 fatty acids has heightened among all species in recent years, and equine researchers have begun to study their effectiveness in horses.

• Research carried out at Kentucky Equine Research (KER) has shown supplementation with omega-3-rich fish oil KERx EO·3 elevates EPA and DHA concentrations in equine serum and red blood cells. In a recent study, horses fed 60ml of fish oil showed rapid increases in the levels of EPA and DHA in serum and red blood cell membranes compared to horses fed 60ml of corn oil (Figures 1 and 2).

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• Reproductive specialists obtained encouraging results in studies carried out on stallions: in some stallions there was a significant boost in the number of normally shaped sperm, motility after chilling or thawing frozen semen and a rise in the concentration of spermatozoa in the semen.

• Nutritionists uncovered interesting results when omega-3 fatty acids were fed to pregnant mares. The mares passed along the fatty acids to their foals in their milk. These foals seemed to have a stronger immune status than foals suckling mares not fed omega-3 fatty acids.

Research is full of possibilities. As such, scientists are looking into other ways in which omega-3 fatty acids may benefit horses.

• Bleeders.

Omega-3 fatty acids play a role in the flexibility of cell walls. Increased flexibility of the membranes of red blood cells is crucial, especially during exercise when heart rates increase, blood thickens and packed cell volume rises. Increased elasticity of red blood cells allows easier passage through narrow blood vessels in the lungs and muscles, thereby improving blood supply and oxygen delivery. Scientists at Kansas State University reported a reduction of EIPH severity (bleeders) in Thoroughbreds after being fed a diet enriched with fish oil for 83 days. Other studies have reported increased red blood cell membrane fluidity during exercise in horses fed a diet enriched with DHA and EPA and this or the anti-inflammatory effect may lead to the reduced severity of EIPH.

• Inflammation.

Scientists at Texas A&M University have reported that supplementation with omega-3 fatty acids reduced joint inflammation in both yearlings and older, arthritic horses. Horses fed the omega-3 supplement had lower synovial fluid white blood cell counts than those in the control group. Raised white blood cell counts are indicative of local inflammation, and arthritic horses will typically have a much higher number of white blood cells than non-arthritic horses. Increased mobility in the supplemented arthritic horses was not reported.

§ Lameness & Stride Length.

Studies conducted by the Michigan State University concluded that horses supplemented with a dietary source of EPA and DHA showed a significant increase in the plasma fatty acid profile. In this study, adding the EPA and DHA forms of Omega-3 to the horse’s diet resulted in a longer trot stride length, presumably as a result of the reduced inflammation and decreased joint pain[i].

• Reproduction in Mares.

Researchers are studying the effects of omega-3 fatty acids on estrous cycles and pregnancy rates of mares, with a possible connection to reproductive function. Recent results in cattle and pigs show that supplementation with fish oil may increase embryonic survival and pregnancy rates. In mares, supplementation with fish oil has led to reduced prostaglandin secretion and increased progesterone levels and this may aid embryo survival.

• Antioxidant Status

Investigators are looking into the possible antioxidant properties inherent in omega-3 fatty acids and work has shown that supplementation with fish oil can boost antioxidant status.

Where to Find the Omegas

Feedstuffs have varying levels of omega-3 and omega-6 fatty acids. Some may already have a place on your feed room shelves, but others may not. Here’s a quick reference list.

Rich in omega-6 fatty acids:

§  Corn oil

§  Safflower oil

§  Rice bran oil

§  Sunflower oil

Feeding one or more of these, especially in combination with a high-grain diet, may supply a horse with a surplus of omega-6 fatty acids, skewing the ratio of omega-3 to omega-6 fatty acids.

Rich in omega-3 fatty acids: fish oils (cold-water species) and linseed oil. Fish oil is a direct source of EPA and DHA. Linseed oil, on the other hand, yields ALA, which then must be converted to EPA and DHA by an enzyme that has competition for its activity.

Give Omega-3 Fatty Acids Time to Work

It is important to realize that rapidness of response to supplementation is dependent on the pathway of action. Elevated plasma levels and endocrine and cytokine actions are more rapid than enhanced semen or red blood cell characteristics. It takes around 60 days for the full spermatogenesis process to occur and the life cycle of a red blood cell is approximately 120 days. Therefore, a positive effect on bleeders requires at least 150 days of supplementation in order for DHA and EPA to be fully incorporated into all the red blood cells.

Omega-3 fatty acid supplementation is a smart way to offset the skewed ratio of omega-3 to omega-6 fatty acids when high-grain rations are fed to horses. Grains contain low levels of omega-3 fatty acids, so as more cereal grains are fed the percentage of omega-3 fatty acids in the diet decreases. Positive effects on reproduction and fertility, joint health, airway inflammation and exercise-induced pulmonary hemorrhage (bleeders) have been reported after supplementation with long chain omega-3 fatty acids EPA and DHA. Commonly supplemented fats such as corn oil have a low omega-3 to omega-6 fatty acid ratio and therefore only compound the problem off too few omega-3 fatty acids in the diet. The most effective way of delivering the beneficial DHA and EPA omega-3 fatty acids is through the feeding of fish oil.

This article is reprinted with the permission of Kentucky Equine Research. For further information and nutrition advice, please contact KER on 1800 772 198, advice@ker.com or www.ker.com.