Rice bran oil (RBO) is an increasingly popular fat supplement fed to horses for weight management, cool energy, and coat quality.

The oil is derived from the germ and bran of brown rice grains and contains essential fatty acids and antioxidants. [1][3][4][5] Rice bran oil is palatable and provides a dense source of calories for horses.

RBO is primarily composed of monounsaturated fatty acids and polyunsaturated fatty acids. [1] It contains 42.6% oleic acid (an omega-9 monounsaturated fatty acid) and 28% linoleic acid (an omega-6 polyunsaturated fatty acid). [1]

Continue reading to learn about the benefits of feeding rice bran oil to horses and some considerations when adding fat to your horse’s diet.

Rice Bran Products for Horses

Mainly produced in Japan, Thailand, India, China, and Vietnam, rice bran oil is primarily used in the food industry and for industrial applications. [1][2] RBO has a neutral flavor and high smoke point, which makes it ideal for high-temperature cooking.

The oil is harvested from the bran layer which between the outer hull and inner germ, which is rich in vitamins and other nutrients.

Compared to many other vegetable oils, rice bran oil contains a higher level of antioxidants, including vitamin E, gamma-oryzanol, and phytosterols. [1][6] These nutrients offer a range of health benefits.

Rice Bran

The bran component of rice kernels is commonly used in horse feeds and retains naturally present fatty acids, so long as the oil is not extracted.

Rice bran contains up to 20% oil and must be heat- and pressure-stabilized before feeding to prevent rancidity and digestive issues.

Rice bran consists of 21% non-structural carbohydrates (primarily starch and sugars). For horses that need to avoid high-NSC diets, the oil is carbohydrate-free and may be a better alternative.

The bran can also be high in phosphorus and low in calcium, or high in both minerals. Calcium and phosphorus levels meet the individual requirement levels and fall within specific ratios to optimize support of metabolic processes.

Rice Bran Oil Extraction

RBO is typically extracted through a solvent extraction process. [1] It can also be cold-pressed to retain more natural flavors and nutrients.

After milling, RBO oil is prone to degrade when exposed to light and air. If the oil is not stabilized through a heat treatment process, it has a shorter shelf life.

Some rice bran oil products are stabilized immediately after production to reduce lipase activity. This is an enzyme that breaks down fatty acid components of the oil.

Rice bran oil is low in potassium, which makes it safe for horses with Hyperkalemic Periodic Paralysis Disease (HYPP).

Both rice bran and RBO contain a high amount of omega-6 fatty acids and a negligible amount of omega-3 fatty acids. [1] Equine diets containing these fat sources should be properly balanced to ensure horses are receiving enough omega-3 fatty acids.

Nutritional Profile

Digestible Energy

Rice bran oil provides approximately 9.5 megacalories (mcal) / kg of dry matter (DM).

A typical adult horse at maintenance requires 16.65 mcal of digestible energy per day.

Fatty Acid Composition

The fatty acid composition of RBO is: [1]

  • 44% monounsaturated fatty acids
  • 6% polyunsaturated fatty acids
  • 5% saturated fatty acids

Unsaturated fatty acids present in RBO include: [1]

  • Oleic acid: 42.6% (omega-9 monounsaturated fatty acid)
  • Linoleic acid: 28% (omega-6 polyunsaturated fatty acid)
  • Linolenic acid: 0.8% (omega-3 and omega-6 polyunsaturated fatty acids)

Of the linolenic acid component of RBO, 0.5% is omega-3 fatty acids, and 33.1% is omega-6 fatty acids. [1]

The overall ratio of omega-6 to omega-3 fatty acids in rice bran oil is approximately 56:1.

Omega-3 and omega-6 fatty acids are essential for equine health and must be provided by the diet as the body cannot make them. Omega-6 fatty acids are important as they support inflammatory processes that are beneficial for fighting off infections and supporting tissue repair.

However, diets containing excessive omega-6 fatty acids and insufficient omega-3s can promote inflammation.

Nutrients

RBO is high in vitamin E and contains both tocopherols and tocotrienol forms of the nutrient. [4][7]

Unrefined RBO is higher in vitamin E than refined oil and contains approximately 24 to 60 mg of tocopherols/100 g of oil and 71 to 75 mg of tocotrienols/100 g of oil. [8]

Gamma-oryzanol is a group of antioxidant plant chemicals (ferulic acid esters and phytosterols) present in rice bran oil at a level of approximately 1 to 2%. [4][7][9]

Rice bran oil contains approximately 1 to 2% naturally occurring phospholipids, including lecithin. [10] Phospholipids are fatlike, phosphorus-containing compounds that serve metabolic and structural functions in cells. [11]

Benefits of Rice Bran Oil for Horses

Research on the specific effects of feeding rice bran oil to horses is limited. However, several components of rice bran oil have been studied and shown to support health benefits.

There are also general benefits associated with feeding fat in the equine diet.

Source of Antioxidants

Antioxidants combat cell damage due to oxidation. This process occurs when oxygen atoms interact with other molecules and cause damage by stealing electrons from them.

Free radicals are produced in our bodies due to normal metabolic processes, stress, and environmental toxins. Antioxidants work to neutralize these harmful free radicals, protecting cells in the body.

Vitamin E:

Vitamin E refers to a group of fat-soluble compounds, including tocopherols and tocotrienols, that serve as powerful antioxidants in the body.

Tocopherols and tocotrienols donate electrons to unstable atoms (free radicals) that can damage cells and help prevent cellular damage and premature aging.

Some of the key benefits of vitamin E for horses include:

  • Reduces muscle soreness and stiffness which helps sustain high levels of activity.
  • Helps muscles recover after exercise which can support athletic performance. [12]
  • Lowers the risk of chronic tying up (exertional rhadomyolysis).
  • Boosts the immune response and enhances the capacity of immune cells to kill bacteria. This helps horses recover from illness more quickly. [13]
  • Improves insulin sensitivity.
  • Enhances antioxidant defenses to help minimize stress and health issues related to travel and competition. [14]
  • Guards against the development of neurological disorders, such as equine motor neuron disease (EMND) and equine degenerative myeloencephalopathy (EDM) from developing. [15]
  • May lower oxidative stress in horses with polysaccharide storage myopathy (PSSM)/equine polysaccharide storage myopathy (EPSM).

Gamma-oryzanol:

Human research shows multiple health benefits of gamma-oryzanol, including antioxidant and anti-inflammatory effects. It has also been studied for anticancer, antidiabetic, and cholesterol-lowering effects. [9][16]

In horses, gamma-oryzanol is purported to have an anabolic effect on muscle growth. It is also purported to enhance athletic performance by reducing fatigue and decreasing lactate accumulation in tissues. [9][17][18][19][20]

Gamma-oryzanol is widely available in equine supplements for exercising horses.

Supports Gut Health

Rice bran oil also contains lecithin, which has been shown to support gastrointestinal health and intestinal barrier function in horses. Research shows a combination of lecithin and pectin supports gastric health. [21][22]

The amount of lecithin in rice bran oil is too small to produce the same results seen in research studies, but there could be some gut protective effects conferred by the lecithin content.

Source of Cool Calories

Rice bran oil is a cool energy source that can increase the calories in your horse’s diet without causing excitability or hot behaviour.

Fat is metabolized efficiently and digested slower than carbohydrates, making it an ideal feed to support exercise endurance and recovery. [23]

Unlike grains and starch-based feeds, which can cause hindgut issues, fat does not contribute to a risk of hindgut acidosis, colic, or right dorsal colitis.

Sugar-Free

Rice bran oil does not contain sugar or starch, known as non-structural carbohydrates. This makes it suitable to feed horses with insulin resistance, Equine Metabolic Syndrome (EMS), or Pituitary Pars Intermedia Dysfunction (PPID).

Replacing high-NSC grain in your horse’s diet with rice bran oil can support normal blood glucose levels and metabolic health.

Cost-Effective

Compared to other oils used in the equine diet, rice bran oil tends to cost less. For example, it is cheaper to feed than flax oil, camelina oil, and coconut oil.

Depending on the supplier, it may cost more than canola oil, corn oil and soybean oil.

Good Palatability

Rice bran oil offers a palatable source of fat for horses as it is neutral tasting and has a pleasant smell.

How to Feed Rice Bran Oil

Before adding rice bran oil to your horse’s diet, assess their body condition to determine whether they need extra calories. Track this on a regular basis so you can make adjustments to your horse’s feeding program as needed.

If your horse is a hard keeper and cannot maintain body condition on forage alone, adding concentrated calories from rice bran oil may be beneficial.

Horses in demanding exercise programs that require additional energy can also benefit from added fat.

Feeding Rate

The feeding rate will depend on whether your horse is underweight and your main reasons for feeding fat. Below are some common feeding rates:

  • For coat quality and shine: 30 – 60 mL
  • For performance horses: 100 – 200 mL
  • For weight maintenance: 100 mL
  • For weight gain: 200 mL

Typically, fat should not exceed 8% of the total equine diet. However, horses in heavy work can tolerate up to 20% of their dietary calories provided as fat. [24]

Introduce Gradually

Rice bran oil should be added to your horse’s diet gradually over a period of two to three weeks. This will ensure your horse’s production of bile and digestive enzymes has time to adjust to the higher fat content of the diet.

Start with 30 ml (1 oz) for the first few days and increase incrementally. If feeding high levels of oil, the daily amount should ideally be divided into multiple meals.

Omega-3 to Omega-6 Ratio

Remember that rice bran oil primarily contains omega-6 fatty acids. It has a high concentration of omega-6 linoleic acid and almost no omega-3 alpha-linolenic acid.

Omega-3 fatty acids are important because they support anti-inflammatory processes in the body. Diets that contain excessive omega-6 fats can promote inflammation.

If your horse has health concerns such as joint issues, skin problems, allergies, or other inflammatory conditions, feeding an oil high in omega-3 fatty acids may be more beneficial.

Mad Barn’s w-3 Oil is a fat supplement that contains high levels of docosahexaenoic acid (DHA) – an omega-3 fatty acid. W-3 oil also contains high levels of natural Vitamin E.

Feeding w-3 Oil can support the healthy regulation of inflammatory processes in the horse’s body while supplying cool energy.

w-3 Oil Essential Fatty Acid Supplement

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  • Promotes joint comfort
  • Helps to fight inflammation
  • Skin & coat condition
  • Palatable source of Omega-3's

Summary

Adding rice bran oil to your horse’s diet is a cost-effective way to increase the caloric density of their feeding program and support weight gain or performance.

While rice bran is high in sugar and starch, the oil is low in non-structural carbohydrates, making it appropriate for metabolic horses.

Consider working with an equine nutritionist to determine wich oil is best for your horse based on their overall diet. A nutritionist can also help you determine how much oil to feed your horse to meet their individual needs.

Is Your Horse's Diet Missing Anything?

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References

  1. Sneh, P. et al. Rice Bran Oil: Emerging Trends in Extraction, Health Benefit, and Its Industrial Application. Rice Science. 2021.
  2. Pal, YP. and Pratap, AP. Rice Bran Oil: A Versatile Source for Edible and Industrial Applications. J Oleo Sci. 2017.
  3. Toda, M. Rice Components with Immunomodulatory Function. J Nutr Sci Vitaminol (Tokyo). 2019.
  4. Sohail, M. et al. Rice bran nutraceutics: A comprehensive review. Crit Rev Food Sci Nutr. 2017.
  5. Cheng, HH. et al. Gamma-oryzanol ameliorates insulin resistance and hyperlipidemia in rats with streptozotocin/nicotinamide-induced type 2 diabetes. Int J Vitam Nutr Res. 2010.
  6. Derakhshan-Honarparvar, M. et al. Rice Bran Phytosterols of Three Widespread Iranian Cultivars. J. Agr. Sci. Tech. 2010.
  7. Mingyai, S. et al. Physicochemical and Antioxidant Properties of Rice Bran Oils Produced from Colored Rice Using Different Extraction Methods. J Oleo Sci. 2017.
  8. Endo, Y. and Nakagawa, K. Differences in the Compositions of Vitamin E Tocochromanol (Tocopherol and Tocotrienol) in Rice Bran Oils Produced in Japan and Other Countries. J Oleo Sci. 2021.
  9. Scavariello, EM. and Arellano, DB. Gamma-oryzanol: un importante componente del aceite de salvado de arroz [Gamma-oryzanol: an important component in rice brain oil]. Arch Latinoam Nutr. 1998.
  10. Lehri, D. et al. Composition, production, physicochemical properties and applications of lecithin obtained from rice (Oryza sativa L.) – A review. Plant Science Today. 2019.
  11. Lichtenberger, L.M. et al. Association of phosphatidyl choline and NSAIDs as a novel strategy to reduce gastrointestinal toxicity. Drugs of Today. 2009.
  12. Fagan, MM et al. Form of Vitamin E Supplementation Affects Oxidative and Inflammatory Response in Exercising Horses. Journal of Equine Vet Med. 2020.
  13. Petersson K H et al. The Influence of Vitamin E on Immune Function and Response to Vaccination in Older Horses. J Anim Sci. 2010.
  14. da Fonseca, LA et al.Influence of selenium and vitamin E supplementation on energy
    metabolism in horses used in policing activity
    .Comp Clin Pathol. 2016.
  15. Finno, CJ and Valberg,SJ A Comparative Review of Vitamin E and Associated Equine
    Disorders
    . J Vet Intern Med. 2012.
  16. Ramazani, E. et al. Biological and Pharmacological Effects of Gamma-oryzanol: An Updated Review of the Molecular Mechanisms. Curr Pharm Des. 2021.
  17. Waraksa, E. et al. A rapid and eco-friendly method for determination of the main components of gamma-oryzanol in equestrian dietary and nutritional supplements by liquid chromatography-Tandem mass spectrometry. J Pharm Biomed Anal. 2019.
  18. Ramazani, E. et al. Biological and Pharmacological Effects of Gamma-oryzanol: An Updated Review of the Molecular Mechanisms. Curr Pharm Des. 2021.
  19. Szcze?niak, KA. et al. Transcriptomic profile adaptations following exposure of equine satellite cells to nutriactive phytochemical gamma-oryzanol. Genes Nutr. 2016.
  20. Chodkowska, KA. et al. Simultaneous miRNA and mRNA Transcriptome Profiling of Differentiating Equine Satellite Cells Treated with Gamma-Oryzanol and Exposed to Hydrogen Peroxide. Nutrients. 2018.
  21. Venner, M. et al. Treatment of gastric lesions in horses with pectin-lecithin complex. Equine Vet J Suppl. 1999.
  22. Ferrucci F. et al. Treatment of gastric ulceration in 10 standardbred racehorses with a pectin-lecithin complex. Vet Rec. 2003.
  23. Mowry, KC. et al. Effects of Crude Rice Bran Oil and a Flaxseed Oil Blend in Young Horses Engaged in a Training Program. Animals (Basel). 2022.
  24. Geor, R.J. and Harris, P.A. Nutrition for the equine athlete: above and beyond nutrients alone. In: Equine Sports Medicine & Surgery. Saunders. 2014.