Lipids In the Equine Diet

Lipids are an important part of the horse body. They make up the majority of cell walls, transport fat-soluble vitamins to their destinations, and are integral in many other body functions.

They are divided into two classes: fats and oils. Fats are those that are generally solid at room temperature, while oils are generally liquid at room temperature.

The term lipids includes a number of various chemical compounds that are insoluble in water but soluble in organic solvents. Included substances are:

  • Triglycerides
  • Fatty acids
  • Cholesterol
  • Phospholipids
  • Sterols

Triglycerides are the most common lipid found in the equine body. They are composed of three fatty acids bound together by a glycerol molecule at one end.

The fatty acids are each composed of a chain of carbon atoms, anywhere from three to twenty-four atoms long. One end, designated the alpha end has what is called a carboxyl group, which is a carbon bound to two oxygen atoms and a hydrogen atom. At the other end, the omega end, is a methyl group.

Saturated vs. Unsaturated

Lipids are classified as saturated when they have no double bonds between carbon atoms. When there are no double bonds, the molecules form a straight line, and multiple molecules can be packed in very tightly in straight lines.

Fats are generally made up of triglycerides that have mainly saturated fatty acids in them. Because saturated fatty acids are less susceptible to heat, these tend to be solid at room temperature.

Unsaturated fatty acids are those that have at least one double bond. Fatty acids with one double bond are classified as monounsaturated fats, while those with two or more double bonds are classified as polyunsaturated fats.

These double bonds interfere with the ability of the molecules to pack in tightly, so unsaturated fats are loosely packed molecules.

Oils will generally be made up of triglycerides that have unsaturated fatty acids as the main component. These fatty acids are more susceptible to heat (due to being loosely packed) than saturated fatty acids, so they are generally liquid at room temperature.

The Omegas

Fatty acids can also be grouped by where their first double bond is located.

If the first double bond is located between the third and fourth carbon from the omega end, the fatty acid is said to be an omega-3 fatty acid.

If the first double bond is between the sixth and seventh carbons, then the fatty acid is an omega-6 fatty acid.

Lastly, if the first double bond is between the ninth and tenth carbons, then it is an omega-9 fatty acid.

Any fatty acid with the first double bond between any carbon sooner than the ninth carbon cannot be synthesized in the equine's body. This means that neither omega-3's or omega-6's can be synthesized by your horse.

Since omega-3's and omega-6's are very important to your horse's body, they must come from somewhere. That somewhere is the diet.

Any fatty acid that cannot be synthesized in the body is referred to as an essential fatty acid, since it must be present in the diet for the horse to obtain it.

For more information on omega-3's and omega-6's, check out the following links:

Omega-3 Fatty Acids
Omega-6 Fatty Acids

Lipids are an essential part of every horse's diet, and I hope this information has helped you understand more clearly how they work in your horse's body.

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