How long has it been since you really looked at the content of your horse's concentrate feed? If you're like many of us, you probably stand in line at the feed store, ask for "three bags of the 12%," heave the feed into the back of your truck, and drive on home without as much as a second glance at the ingredients or the nutrition in that ration. It's what you've always bought, and the horses like it fine...that's what's important, right?
Chances are, you haven't taken the time to read that little label sticking out from the bottom of the bag. That's a shame--because the tag attached to each bag of commercial horse feed can supply a wealth of information to the consumer who reads the fine print. Learning to interpret the information supplied by the manufacturer isn't all that difficult, and it can tell you whether the feed you're buying is truly the best choice for your horse.
Commercial feed products are regulated by the Uniform State Feed Bill, developed by the Association of American Feed Control Officials (AAFCO). The Bill, which became effective in 1994, sets guidelines for the content and format of feed labeling, and Sally Puzacke, equine specialist at Buckeye Feed Mills, says that the vast majority of states comply with the AAFCO format. Although the exact content of a feed tag might vary somewhat from state to state, there are certain values that are considered mandatory, and should provide enough information for any horse owner to be able to make an informed choice.
Feed labels on horse feeds should include:
* The product's name--which must accurately reflect the intended use of the feed. For example, a feed designed for mature horses in light work would be labeled a "maintenance" feed so as not to imply it is appropriate for growing foals.
* A purpose statement--describing the species and the class of animal for which it is intended (breeding, maintenance, lactation, growth). Again, this is intended to help the buyer make the choice best suited to his or her animals.
* A description of the feed format--for example, pelleted, textured (the industry name for what most of us call "sweet feed"--mixed grains with molasses added for flavoring), or extruded.
* A Guaranteed Analysis--which is where the labeling might vary somewhat according to the state in which the feed is manufactured. AAFCO's minimum requirements are for statements of crude protein, crude fiber, and crude fat (expressed as percentages), minimum and maximum percentages of calcium, and minimum values for phosphorus (%), copper (parts per million, or ppm), zinc (ppm), selenium (ppm), and vitamin A (International Units per pound). This is a significant improvement over the labeling standards of just a few years ago, when American consumers got the bare minimum of protein, fat, and fiber values. In addition to the numbers required by AAFCO, feed companies will sometimes list other ingredients, especially where the amount included might be of special interest to the buyer. Vitamin E and biotin, for example, might make the ingredient list on the theory that many horse people are interested in feeding supplemental levels of these vitamins. Puzacke notes, however, that "the more ingredients you list, the more you're open to testing and verification that all the levels are dead on--so manufacturers tend to be conservative about it."
* An ingredient list--which might list every ingredient in the feed, but more often is deliberately vague. There are two reasons for this: First, some feed formulas are designed to be variable, so that one ingredient (providing similar nutrition) can be substituted for another as grain market prices fluctuate. With a variable formula feed, the manufacturer would go to considerable expense reprinting feed labels every time the formula changed slightly. Also, many manufacturers prefer not to divulge the exact formula for their grain rations, for fear of being copied by the competitors. So, instead of specific ingredients like soybean meal or cottonseed meal, you might see phrases like "plant protein products" listed on the feed label; instead of brewer's yeast, wheat bran, or corn gluten feed, you might see a listing for "processed grain by-products." This approach is sanctioned by the AAFCO, and it helps manufacturers keep costs down--but it can make it difficult for consumers to evaluate what they're buying. Puzacke notes that some states, such as Florida, require a complete ingredient list rather than the "shortcut approach."
* Directions for use--this usually includes a chart or guideline for feeding amounts, calculated based on the weight of the horse and the extent of his work schedule. These guidelines usually are calculated so that, along with an appropriate forage product (pasture or hay), the feed will provide complete nutrition when fed in the recommended amounts.
"What people often don't realize, or don't pay attention to," says Puzacke, "is that the product will only do what it says it will do if you feed it according to the directions! Feeding reduced quantities 'dilutes' the nutrition of a formulated feed product, and so does 'cutting' the product with straight oats, or bran. Try to stick to the manufacturer's directions as much as possible--they are calculated for a reason."
* The net weight of the feed (useful when calculating your feed cost per day).
* The manufacturer's name and address--provided so that the consumer can contact the manufacturer should questions or problems arise. Most companies are willing to answer questions and get feedback from their customers, and many have specialists in equine nutrition available to address your problems.
In addition, although it's not required, most feed companies provide a date of manufacture somewhere on the bag or feed tag. Often, though, it's encoded, so that the feed store employees can read it, but the consumer cannot. The reason for this, says Puzacke, is that people often confuse the date of manufacture with an expiration date, and assume the feed is out-of-date and "stale." An average pelleted or sweet feed, correctly stored, has a shelf-life of about six months, according to most sources, and a fat-supplemented one (which is more prone to spoilage), about three months. If you'd like to ensure the best available freshness for your horses, look for a date stamp, or ask your feed store representative to translate the code for you.
Let's take a look now at some of the numbers on that Guaranteed Analysis on your feed label, and see what they can tell you--and what they can't.
We tend to describe horse feeds in terms of their protein content--10%, 13.5%, 16%, and so on--but protein is neither the primary source of energy in the feed, nor necessarily an indicator of its quality. In other words, a feed with a higher protein percentage is not necessarily a better feed, or a better choice for your horse. In fact, most mature horses' diets include too much protein, rather than too
little. But because protein is a relatively expensive ingredient, the price of the feed does tend to reflect the protein value.
The percentage of crude protein expressed on a feed label is calculated from the nitrogen content of the grain; nitrogen is contained in amino acids, the "building blocks" of protein. The most critical of these amino acids is lysine, often called the "first limiting" amino acid because it must be present in sufficient quantity in order for the horse's gut to absorb and utilize any of the other amino acids in the protein chain. Good sources of protein for horses (such as soybean meal) have lots of lysine--but unfortunately, the crude protein percentage on the bag won't tell you what the source is, or how good that ingredient's amino acid profile is. (Some companies now list lysine values in addition to crude protein values--when assessing these, look for a value of 0.65% or higher for growing horses, and about 0.5% for mature horses. Keep in mind that lysine is only one component of the total crude protein.)
The word "crude" on the label is an indicator that not all of the protein included in the percentage listed will actually be digestible by the horse. There will always be a certain amount of protein that the horse's gut just cannot process, which will pass through untouched. If you're calculating a feed ration, deduct 2-5% of the crude protein value on the feed label in order to come up with a ballpark figure for the digestible protein level of the feed.
Crude fat also is expressed as a percentage on a feed tag; it refers to the total ratio of fats and oils contained in the product, including both saturated (animal) fats and unsaturated (vegetable) oils. Fat is energy-dense, providing almost 2 1/2 times as much energy, pound per pound, than do carbohydrates or protein; the higher the crude fat value, the higher the calories provided per pound of feed--so fewer pounds of grain might be needed for the same amount of energy and weight maintenance.
Fat-supplemented feeds are much in favor at the moment, particularly for horses in high-performance sports like endurance racing, three-day eventing, polo, and combined driving. (Many owners find that supplemental fat also contributes to a healthy, shiny haircoat.) An ordinary sweet feed or pellet that is not fat-supplemented runs about 2.5% to 3.5% crude fat, which is the amount of fat naturally found in the grains. If you're looking for a fat-supplemented feed, look for a product with a value of 5% or higher (to a maximum of about 10%).
The crude fiber value of a feed plays a major role in determining the energy content of a feed. Generally, as the fiber percentage decreases, the calories per pound go up; and as fiber levels increase, the calories go down. Therefore, high-fiber feeds must be fed in larger quantities in order to maintain the same calorie intake per day, and this may mean that feeding a high-fiber feed is more expensive in the long run. High-fiber feeds (those with fiber values higher than 10%) usually are designed to be "filling," low-calorie feeds for mature horses which are idle or in light work, or to be fed to horses which cannot eat hay (usually because of a respiratory condition such as COPD).
The word "crude" in the case of fiber describes both the digestible and indigestible fiber in the feed. Digestible fiber is the type from which the horse's gut can absorb nutrients; think of the relatively soft leaves in a flake of hay, or of beet pulp. Indigestible fiber, such as oat hulls, wheat chaff, or soybean hulls, generally is tougher in texture (because of a higher percentage of lignin, the fibrous substance that makes up tree bark, among other things) and is not digested, but a small amount in the feed is helpful in maintaining good intestinal health. (Which means it keeps the intestinal contents "moving along.") Large quantities of indigestible fiber, however, are an indicator of a poor-quality feed that is using "fillers." Unfortunately, there's no way to tell from the crude fiber percentage how much of each type the feed contains.
Minerals And Vitamins
Calcium and phosphorus are probably the two most crucial mineral levels to note on a feed tag. This is because they are so important for the development, maintenance, and repair of the musculoskeletal system, and because they both must be present in sufficient quantity in order to fulfill their functions. The amount of the minerals, and their ratio to each other, are key. Growing horses (up to about two years) need higher amounts of both calcium and phosphorus--an appropriate ration for a six-month-old weanling, for example, will have at least 0.7% calcium and 0.4% phosphorus, while a mature horse can get by with about 0.3% calcium and 0.25% phosphorus. Most feeds supplement a little higher than this, and it's usual to see calcium (Ca) values of 0.8% to 9.0%, and phosphorus (P) values of 0.6% to 0.8%. (Lactating mares might need particularly high calcium support in order to produce good-quality milk, so many feeds designed for broodmares boost the calcium levels above 1.0%, and phosphorus to 0.9% or so.)
Calcium and phosphorus should be provided in something close to a one-to-one ratio; in fact, the ideal is about 1.2 Ca to 1 P, up to about 1.8:1. Horses can tolerate considerable variation in this ratio, however, as long as there is always at least as much calcium as phosphorus available.
Feeds can be formulated to take into account the calcium and phosphorus concentrations in forage. Legume hay, as a rule, has a much higher concentration of calcium than does grass hay; therefore, you might choose a feed that's higher in calcium if you're feeding timothy hay than if you're feeding alfalfa hay. Some companies will go into some detail on their feed labels as to the most appropriate forage to partner with their grain formula.
Copper, zinc, and selenium are trace minerals which are needed in much smaller quantities in the horse's diet than are calcium and phosphorus. Nonetheless, they play an important role in the horse's overall health. Copper and zinc deficiencies have been tied to developmental orthopedic problems in growing horses, so in recent years, many manufacturers have increased the amount of copper (Cu) and zinc (Zn) in their feeds for weanlings, yearlings, and broodmares.
Selenium is "linked" with vitamin E in the horse's immune and breeding health. While it is important, it is also one of the only minerals that has a very low toxicity level, so owners must be careful not to overfeed it. If your grain ration lists selenium (Se) in its ingredient list, avoid feeding supplements that also contain selenium--and ask your veterinarian or state extension specialist whether your local soils are selenium-deficient or selenium-rich (there are even a few locations in North America where the soils are selenium-toxic). Some feed companies will print a warning message on their feed tags about selenium, to the tune of: "Do not permit intake of supplemental selenium to exceed 0.3 ppm in the total ration (hay or forage plus grain)." In Canada, this warning is mandatory if the feed contains supplemental selenium. (Remember that a grain ration is only part of your horse's daily intake, so don't panic if you see, for example, a selenium level of 1.00 ppm on your feed label! If your hay is grown in a selenium-deficient area, it will contain practically none of the mineral, which will make the overall concentration in your horse's daily diet quite safe. Manufacturers often will alter their recipes for feed rations for different locations, in order to take into account things like selenium toxicity.)
Vitamin A, which is not present in any appreciable degree in grains, is obtained by the horse mostly in the form of beta-carotene from hay or forage. But because this vitamin, important for vision, bone and muscle growth, skin tone and health, and the reproductive health of mares, tends to break down rapidly after hay is cured (decreasing in activity by an average of about 9.5% per month), it is almost always supplemented in grain rations.
Vitamin A should be present in the diet in amounts of about 4,400-6,600 IU/lb. for mature horses, and Puzacke says that consumers should be very careful to note the units used. Some companies, she explains, will express vitamin values in IU/kg (kilograms), which can make less look like more! When comparing feeds, she recommends "that you make sure you're comparing apples to apples!"
What the Tag Tells You
If we were to cover up the name and the purpose statement of a mystery bag of feed, what could we tell about that ration just by looking at the numbers on the guaranteed analysis? Quite a lot, actually.
For instance, if we have a tag listing the crude protein level as 10%, and crude fiber as 15%, that immediately tells us this is a feed designed for mature horses which are idle or in very light work--perhaps targeted at older horses, school horses, or "easy keepers" (those who gain weight easily on high-energy feeds).
What about a feed with 12% crude protein, Ca of 1.15%, P of 0.7%, and a copper level of 55 ppm?
This is likely a feed designed for a broodmare in the first eight months of gestation. The extra mineral support will help her "build" a foal with strong bones and muscles, but she has no requirement for extra protein until the final trimester, when the fetus is growing most rapidly.
How about a feed with 12% crude protein, 7% crude fat, and lysine, methionine, biotin, vitamin E, and thiamin levels listed on the tag? Almost certainly, this is a feed designed for horses in "high performance" sports, such as racing, endurance riding, or three-day eventing. The supplemented fat supplies extra energy and calories, the protein level is fairly low because the horse is mature, and the "extras" listed on the feed tag are there to inform the buyer of the (presumably) high levels of these ingredients, which would be beneficial to a horse in hard, stressful work.
Although the feed tag doesn't tell you everything, it can be a valuable reference guide, particularly when combined with an analysis of your forage. If you have questions about the information on the label (or what is not on the label), don't proceed in the dark--contact your feed salesperson, your veterinarian, or your feed company's equine specialist.
About the Author
Karen Briggs is the author of six books, including the recently updated Understanding Equine Nutrition as well as Understanding The Pony, both published by Eclipse Press. She's written a few thousand articles on subjects ranging from guttural pouch infections to how to compost your manure. She is also a Canadian certified riding coach, an equine nutritionist, and works in media relations for the harness racing industry. She lives with her band of off-the-track Thoroughbreds on a farm near Guelph, Ontario, and dabbles in eventing.