Understanding Horse Feed Analysis Results: A PrimerBy Kentucky Equine Research Staff · October 5, 2015
Imagine you’re faced with three horse feed choices: steam-crimped oats, an underfortified feed made in-house by the local feed store, and a well-fortified feed formulated and manufactured by a reputable company. The feeds are priced accordingly, with oats the least expensive and the well-fortified feed the most expensive. Faced with only the facts presented in this table, what problems can you pinpoint?
Scratching your head?
We’ve asked equine nutritionist Kathleen Crandell, Ph.D., of Kentucky Equine Research to help us review these three feeds, citing differences and potential problems.
Energy. The energy in these feeds, listed as “Digestible energy, Mcal/kg,” is comparable, with both the well-fortified feed and steam-crimped oats having slightly more energy than the underfortified feed. What’s this mean in terms of feed quality? All three feeds will provide a similar amount of energy to horses when fed in the same amounts on a by-weight basis (pound for pound or kilogram for kilogram).
Crude protein. The well-fortified feed has a significant advantage in protein content, with 14.4%. This is likely due to inclusion of a superior protein source such as soybean meal or another soybean byproduct. What’s this mean in terms of feed quality? Protein is an important nutrient for growth as well as muscle accretion and repair. For young horses, broodmares, and performance horses, the well-fortified feed is the best bet. Protein quality, especially in straight grains like the steam-crimped oats, is usually incompatible for optimal growth, as lysine will be insufficient. Lysine is an essential amino acid found in high-quality protein sources.
Fiber. Neutral detergent fiber (NDF) is a measure of hemicellulose, cellulose, and lignin, all of which are considered structural carbohydrates. Lignin is indigestible. Acid detergent fiber (ADF) is a measure of cellulose and lignin, with cellulose digestibility varying depending on lignin content. As lignin increases, digestibility of the cellulose decreases. What’s this mean in terms of feed quality? The steam-crimped oats have a high NDF and ADF because of the intact oat hulls. The hulls contribute to the higher fiber values because they are rich in lignin, and therefore add little in the way of nutrition.
Starch. A polysaccharide found primary in grains, starch is a reliable and traditional source of energy for horses. The steam-crimped oats and underfortified feed have much more starch than the well-fortified feed. What’s this mean in terms of feed quality? Many horses can handle typical starch levels, like those found in the oats and underfortified feed, without any compromise in health or any change in behavior. A subset of horses, however, does better on low-starch feeds; these include some horses affected with tying-up, insulin resistance, and metabolic syndrome, and those that react to starch-laden diets by becoming high-strung. Typical textured or sweets feeds will contain more starch than the well-fortified feed in the example. The example actually shows a starch content compatible with lower-starch feeds, as the energy provided in the example comes from multiple energy sources, like fat and fiber, not just cereal grains.
Calcium and phosphorus. Two of the most prominent macrominerals, calcium and phosphorus are both important for skeletal and dental health. Calcium is integral to blood-clot formation, muscle contraction, nerve function, and enzyme activation, and phosphorus essential for energy metabolism and other physiological processes. The calcium-to-phosphorus ratio in feeds should be about 1.2-2:1. What’s this mean in terms of feed quality? Of the example feeds, only the well-fortified feed has an appropriate calcium-to-phosphorus ratio of 1.5:1; the ratio for steam-crimped oats is reversed from the desired ratio at 1:5 and for the underfortified feed is 0.8:1. Overcoming a poor calcium-to-phosphorus ratio can be achieved through the feeding of alfalfa (lucerne) hay or by fine-tuning the diet to include a ration balancer pellet.
Other minerals. The well-fortified feed contains higher levels of most minerals, including potassium, sodium, iron, zinc, manganese, and copper, which indicate significant fortification has been added. Because the values for the underfortified feed are slightly higher than those reported for the steam-crimped oats, some fortification has occurred. For optimal nutrition, horses consuming diets consisting partially of steam-crimped oats or the underfortified feed should be given further vitamin and mineral supplementation.
Seeking guidance from an equine nutritionist is wise if you’re uncertain how to best feed your horse. Kentucky Equine Research (KER) has nutrition advisors available to help you. Feel confident about your horse’s diet by talking to a nutrition advisor.