Oil Seed and Oils
Fats and oils can be added to increase the energy density, or substitute for starch and sugars from grain (1). Other potential benefits of adding fats and oils to a diet are improved efficiency in energy generation, enhanced body condition, reduced excitability and increased metabolism of fats during exercise (1). Fats and oils are also carriers for the fat-soluble vitamins A, D, E and K (2).
The terms, “fat,” and “oil,” are used interchangeably; both are in the lipid category of organic molecules. The distinguishing characteristic between fats and oils is whether it is in a solid or liquid state at room temperature. Fats are solid, and oils are liquid (2). The main component of fats and oils are triglycerides (glycerol molecule with three fatty acid chains attached), free fatty acids, phosphatides (natural emulsifier), sterols, fat-soluble vitamins, tocopherols, pigments, waxes and fatty alcohols (2). The non-triglyceride components constitute only about 2% of crude oils (2).
Omega-3 and Omega-6 fatty acids
Fats and oil vary in fatty acid composition of component triglycerides and free fatty acids, specifically the essential omega-3 and omega-6 fatty acids. Certain fats and oils can be added to a feed to meet a targeted level of either or both essential fatty acids. Fish oil and flaxseed oils are rich sources Omega-3 fatty acids whereas corn, rice bran and soybean oils are richer is Omega-6 fatty acids. Equine nutritionists are now looking at balancing the ratio of Omega-6 to Omega-3 fatty acids rather than just favoring one or the other (3).
Oxidation (Rancid)
Fats and oils can rapidly become rancid (oxidized), depending on the degree of saturation; saturated, monounsaturated, polyunsaturated. The greater the degree of unsaturation, the more susceptible the oil is to oxidation (1). Antioxidants such as Vitamin E are added to retard oxidation. Oils ingredients with high oil content, like rice bran, that are treated with antioxidants will have “stabilized” in the ingredient name. Metals such as copper and iron facilitate oxidation. Citric acid can be added to bind (chelate) these metals (2)
Protein Source
Oil seeds contain significant amounts of protein and are often added to feeds for the protein. Soy protein is a common plant protein used equine feed, and human foods (tofu, soy milk).
NRC. (2009). Nutrient Requirements of Horses . (6th Ed.) National Academy Press, Washington D.C.
Strayer et al.(2006). Food Fats and Oils (9th Ed.). New York: Institute of Shortening and Edible Oils
Equusmagazine.com. (2013, September 4). Which oil is best for my horse? Equusmagazine.com
Definitions terms per AAFCO 2017 Official Publication
Ground, grinding = (Process) Reduced in particle size by impact, shearing, or attrition.
Hulls = (Part) Outer covering of grain or other seed.
Husk = (Part) Leaves enveloping an ear of maize; or the outer coverings of kernels or seeds, especially when dry and membranous.
Meal = (Physical form) An ingredient which has beed ground or otherwise reduced in particle size.
Toasted = (Process) Browned, dried, or parched by exposure to fire, or to gas or electric heat.
Common Oil Seed and Oil Product Ingredients
Broken oil seeds
Canola meal
Canola seed
Corn germ
Corn germ meal
Cottonseed meal
Fat product (feed grade)
Fat, Animal (preserved with BHA and BHT)
Fat, dried vegetable
Fat, vegetable
Flaxseed/Linseed
Flax, Golden, ground
Flax, ground
Flaxseed
Flaxseed (stabilized)
Flaxseed meal
Flaxseed, ground
Flaxseed, heat processed
Flaxseed, whole, ground
Linseed
Linseed meal
Oil, flax
Oil, flaxseed
Horse bean flakes
Oil, Fish
Oil, vegetable
Oil, vegetable, mono and diglycerides
Oil, vegetable, refinery lipid
Palm oil
Porcine and vegetable fat (preserved with BHA and BHT)
Rice
Oil, Rice Bran
Rice bran
Rice bran, stabilized
Rolled fava bean
Soybean
Oil, soybean
Soy flour
Soy protein concentrate
Soy protein isolate
Soya beans, toasted
Soya feed Soybean meal
Soybeans, heat processed
Soybean meal, dehulled
Soybean pellets
Soybeans, roasted, ground
Soybeans, whole, ground, extruded
Sunflower seed
Sunflower meal
Sunflower seed
Sunflower seed feed
Sunflower seed, black oil
Vegetable fat, partially hydrogenated
*Vegetable fat product*
Wheat germ
Wheat germ meal
*Vegetable fat product* - vegetable fat or oil, largely free of free fatty acids and non-triglyceride substances from fats (AAFCO 2017 Official Publication, ingredient 33.2)