What is in a bag of feed?

When purchasing feed one should check to see what the analysis of feed is. The list of guaranteed analysis is required by law in most parts of the world. In addition to the guaranteed analysis, a list of ingredients must also be on the tag.

The analysis is part of the story, for example the guaranteed protein really tells very little about the digestibility or the amino acid composition of the protein. Normal protein analysis is done by a procedure that measures the nitrogen of a substance. The percent of nitrogen is multiplied by 6.25 to determine protein.

The horse uses amino acids rather that straight nitrogen. Since there are some 22 amino acids in nature, the variety of proteins is virtually endless. Of the vegetable protein source available, soybean meal is probably one of the most digestible and the highest quality for horses. Some manufactures list some amino acids such as lysine and methionine, which appears to be "tag dressing" or "buzz words". Protein sources such a cottonseed meal or lysine tryptophane thus; these amino acids must be added. In these cases the addition of amino acids does not make the feed more nutritious but may look impressive.

In feeds, when the list of ingredients do no list grain such as corn, oats etc. but rather the listing is grain products which consist of any grain and may differ from batch to batch depending strictly on price. If a manufacturer lists corn as an ingredient, the corn cannot be replaced with wheat or oats and vice versa. The use of grain by products poses an even greater dilemma because this could be wheat middlings, screenings of corn, oat hulls, corncobs, bakery wastes, etc.

Roughage products could vary from excellent alfalfa to beet pulp, oat hulls, etc. Protein products could include any of the available sources such as soybean meal, cottonseed, corn gluten etc. The reason for not listing specific products is so that formulations can be changed without redoing tag labels.

In addition to listing components of the feed the listings must be from the highest concentration to the lowest concentration. In most feeds the energy ingredients are listed first and go down in decreasing order. In some feeds there is a vast array of ingredients, which may appear very impressive but in most cases serve little purpose except to fill the bag.

Recently "Senior Feeds" have become very popular. Senior feeds should be fed to horses that have difficulty chewing hay. These feeds typically contain 15% to 17% fiber. Senior feeds also contain higher levels of fat which is needed because fat is easier to digest than is true for fiber. Aged horses that cannot chew hay also have a slowed digestion and metabolism and that is why fiber is ground and fortification is increased.

We also are hearing a great deal about "proper balance" of Omega 3 and Omega 6 (with Omega 9 lurking in the wings) when no one, that I am aware of, has the faintest idea what constitutes a "proper" balance of fatty acids since any excess of essential fatty acids will be rapidly burned for energy thus adding calories to the diet and not interfering with use of other nutrients.

The B-complex vitamins such a thiamin, riboflavin, niacin, B12 etc. are generally listed but in some cases they are listed in several ways (thiamin as B) or riboflavin as B2 or vitamin B all the terms are legitimate but appears to be confusing.

Minerals that are in the form of "chelates" are supposed to enhance absorption which may or may not be true. High quality feeds will carry adequate minerals to meet the needs of the horse regardless of form. For example copper or iron listed as the oxides are virtually insoluble and thus cannot be absorbed.