Many surprising benefits have been attributed to the addition of fat to the equine diet and there are many oils available to the consumer; canola, maize, soybean and blends of these to name a few. All have similar levels of energy and omega essential fatty acid profiles. For the first time in Australia a new oil is available to the equine world. Rice Bran Oil has become a quite sought after product not only for its high-energy value and essential fatty acid content, but also as Rice Bran Oil is one of the few natural sources of gamma-oryzanol and ferulic acid.
Rice bran is the outer brown layer of the rice kernel that is removed during the milling process, which generates the familiar white rice. Rice bran is high in fat (around 20%) but is extremely unstable if not refined almost immediately, therefore turning rancid quite quickly. Rice Bran Oil is the refined stabilized oil extracted from the Rice Bran.
What is Gamma Oryzanol?
Gamma oryzanol is a rice bran oil derivative with two major active molecules, Sterol and Ferulic acid. Trials in the U.S., Japan and Australia have shown that gamma oryzanol has positive effects on weight gain and performance comparable to some anabolic steroids. Gamma oryzanol has effects on the body’s endocrine system resulting in increased metabolism of fat and increased synthesis of protein, leading to increased lean body mass.
Research in horses showed the gamma oryzanol group had improved muscle to fat ratio, with better muscle definition in the rump, neck and over the withers. The horses supplemented with gamma oryzanol also maintained appetite better than the control group. In addition, studies have shown that gamma oryzanol is a natural antioxidant and can lower cholesterol levels in the blood.
Gamma oryzanol has also been shown to reduce the risk of gastric ulcers and increased gastrointestinal motility caused by stress. The Gamma Oryzanol / Ferulic Acid molecule is a fat soluble material which means that like fat soluble vitamins A, D, E & K, fat is required for them to be efficiently metabolised in the equines digestive tract.
The Benefits of Antioxidants
At the molecular and cellular levels, antioxidants serve to deactivate certain particles called free radicals. Free radicals are the natural by-products of many oxidative metabolic processes within cells. In horses, free radicals usually come in the form of O2, the oxygen molecule.
If allowed to go their merry way, these free radicals can cause damage to cell walls, certain cell structures, and genetic material within the cells. This is where antioxidants come into play. Antioxidants play an important role, “mopping up” free radicals before they get a chance to do harm to the cell structure. Chemically antioxidants work in several ways;
• They donate electrons,
• They donate hydrogen,
• and they scavenge oxygen or They scavenge free radicals.
Antioxidants can be either synthetic (eg butylated hydroxyanisole -BHA) or natural products such as Vitamins A, C & E, which are also beneficial to the animal because they are essential nutrients.
Vitamin E is thought to be the most effective antioxidant due to its abundance in the body. Rice Bran Oil is abundant with the main forms alpha, beta, gamma and delta tocopherol isomers as well as the most active form of antioxidants known called tocotrienols.
Supplementation of antioxidants are especially important in performance horses as the level of antioxidant reserves in an un-supplemented horse can be quickly eroded when horses are exercising.
What are Fats?
Dietary fats also are known as triglycerides–there are three (tri) fatty acid molecules attached to one glycerol molecule. These fatty acids can be saturated or unsaturated. There can be considerable variation in the size or length of the fatty acids. Fats with unsaturated and/or short fatty acids tend to be in the liquid state at room temperature and are referred to as oils. Conversely, longer chain fatty acids that are saturated usually are solid at room temperature and are referred to as fats.
Why Add Oils?
With the high calorie demands of elite performance horses, Oils plays an important role in reducing grain intake. Oils contain 2.5 times more energy than oats and also are digested more efficiently in the horses’ small intestine. Thus reduces the ‘sugar high’ sometimes associated with high grain intakes.
Unless fat (e.g. some type of vegetable oil) is added to the diet, horse rations are very low in fat, typically less than 2%-3%. However, horses are able to digest and absorb dietary fat quite well (up to 20% of their energy intake). In fact, it is important that horse diets contain at least some fat or oil–it is needed to facilitate absorption of the fat-soluble vitamins A, D, E, and K.
Omega Essential Fatty Acids
The horse also needs small amounts of a linolenic, linoleic and oleic acids. These are special types of fatty acids, which are more commonly known as Omega 3,6and 9 essential fatty acids. Omega essential fatty acid have been shown to improve the health and structural integrity of cell membranes, reduce inflammatory responses from cells, reduce laminitis, stomach ulceration and improve coat and hair condition. As plant oils are high in unsaturated fats they are often high in essential fatty acids such as the Omega group. Such is the case for Rice Bran Oil.
What Type of Horses will Benefit From Being Fed Rice Bran Oil?
High Performance Horses
• Endurance Horses
• Show Preparation
• Yearling Sales
• Horses prone to tying up
• Poor Doers
• Horse with stomach ulcers
• Horses that cannot tolerate high grain diets
The Advantages of Feeding Rice Bran Oil
Reducing the amount of grain in a horses diet and replacing the same amount of energy is quite beneficial to horses in several ways:
Less grain in a horses diet will reduce the caecal burden on the horse’s digestive tract. This will reduce the amount of heat produced in the horse’s hindgut. For horses working in extreme temperatures, the addition of fat into a horses diet will reduce the amount of metabolic heat produced buy the horses and thus able the horse to cope better with the stresses of heat.
Recent research has showed that feeding fat over a period of time can be quite beneficial to horses as the body adapts to using fat more efficiently. This feeding practice has a sparing effect on muscle and liver glycogen levels. It is suggested that this allows for more glycogen to be available at the closing stages of race/performance.
There are also numerous other beneficial reasons to replace some grain with fat such as greater feed efficiency of fat (80-90%) compared to unprocessed grain and most other forages (50-60%). Horses can only consume so much food per day. Adding oil reduces the amount of feed (weight) the horse has to consume in order to meet its energy requirements. When preparing horses for shows and sales, an additional of Rice Bran Oil to the diet can assist in body definition and coat condition.
Why Rice Bran Oil and Not Rice Bran?
For horses that suffer from high grain (starch) diets, nutritionists and veterinarians recommend the addition of fat to the horses diet as a replacement source of energy. Whilst Rice Bran is high in fat (18-20%), Rice Bran is also contains moderate levels of starch (20-30%). Rice Bran Oil contains no starch and thus the addition of this to the diet does not contribute additional levels of starch to the diet.