Forage—hay or pasture—must be the foundation for every feeding program for equines. Forages provide nutrients, adequate chewing time, aid in proper transit through the gastrointestinal tract, and are the main substrate for bacterial digestion in the hindgut. Table 1 lists the expected daily forage and grain intake as a percentage of body weight for various classes of horses. To calculate the pounds required, multiply a horse’s body weight times the percentage. Mature, idle horses should be provided 1.5 to 2% of body weight in the form of forages. This is equivalent to 16.5 to 22 pounds of forage for a 1,100-pound horse. The mature, idle horse will eat 3 to 4 tons of hay per year. For working horses, a minimum of 1% of body weight in forage is important for their digestive tract. Because forage is such a large component of the horse’s diet, knowing how to evaluate forage is critical.
Expected daily forage and grain intake as a percent of body weight
|
Class of horse |
Forage |
Grain |
Total |
|---|---|---|---|
|
Mature, idle horse |
1.5 – 2.0 |
0 – 0.5 |
1.5 – 2.0 |
|
Working horses |
1.0 – 2.0 |
0.5 – 1.5 |
1.5 – 2.5 |
|
Mare, late gestation |
1.0 – 2.0 |
0.5 – 1.0 |
1.5 – 2.5 |
|
Mare, lactation |
1.0 – 2.0 |
0.5 – 1.5 |
2.0 – 3.0 |
|
Weanling |
1.0 – 1.5 |
0.5 – 1.5 |
2.0 – 3.0 |
|
Yearling |
1.0 – 1.5 |
0.5 – 1.5 |
2.0 – 2.5 |
Horses should be fed hay that is of good to high quality. When selecting hay, factors to consider include the composition, maturity, color, and foreign material present. Composition includes the type of hay – alfalfa, grass or a mix of both.
Evaluate the Maturity of The Hay
The stage of maturity, determined by the stem-to-leaf ratio, is the most important selection criteria for hay. The maturity of the plant is not related to a particular cutting, but rather to the stage of maturity when the plant was cut. Mature hay has a much higher stem-to-leaf ratio, resulting in a lower nutrient value of the hay. Leaves are high in energy and protein, while stems are more fibrous and have a lower nutritive value. Plant maturity also can be assessed by the number of seed heads of grasses or flowers of legumes present in the hay.
- As the plant matures, and the plant grows tougher stems so it can stand up vertically. Quality of forages increase up to the time grasses start to get seed heads or legumes flower. As plants progress through seed head or flower bud emergence and seed formation, the concentration of structural carbohydrates and lignin (non-digestible fiber) increase and crude protein decreases. For every 1% increase in lignin, the digestibility of the forage dry matter decreases 3 to 4%.
- The ideal time to harvest legumes is the bud or vegetative stage just prior to flowering.
- The ideal time to harvest grasses is the boot stage when the seed head swells in the leaf sheath but has not yet completely emerged. Grass hays range from vegetative to late heading where seeds form. During the vegetative stage, the plants are leafy and contain fine stems. The reproductive stage is the period when the seed head emerges, develops, and pollination occurs, resulting in seed development. During seed formation or late heading, stems often are coarse and hay or plants are yellow or brown in color.
Evaluate Leafiness and Leaf shatter
Leaves contain more non-structural (digestible) carbohydrates and protein than stems. The more leaves, the more nutrient-dense and digestible the hay is.
- Evaluate the texture by feeling and bending the leaves and stems. Stems of hay should be soft and pliable, rather than coarse and stick-like. The nutritional value decreases as the texture of the stem and leaves changes from fine and easily bendable to rigid and brittle. Early-maturity grass hay has fine, bendable stems and is indistinguishable by feel from leaves. In good-quality grass hays and early maturity, high-quality alfalfa, lignification begins in the stems, but the leaves will be soft and easy to bend. The next stage is characterized by rigid stems and fewer leaves. Hay may feel brittle when bending the stems. Poor hay has inflexible, brittle stems. The highly lignified structures have little nutritional value.
- Leaf shatter results in loss of leaves, and therefore, decreased nutrients. Legumes often have higher leaf shatter losses. The more leaves legume hay loses, the poorer the nutritive value of that legume.
- Leaf loss also may mean the hay was baled too dry. Baling hay at a lower moisture level (too dry) will result in leaf shatter. Hay baled at ideal moisture levels (17 to 20%) has a higher nutrient level due to better leaf retention.
The image below shows examples of stems and leaves in grass and alfalfa. Image A illustrates grass stems, B illustrates alfalfa stems and some leaves, and C illustrates shattered alfalfa leaves.
Look at the Color
Ideally, hay should be a bright green color. The greener the hay, the more carotene (a Vitamin A precursor) and vitamin E. Greener hay also indicates the plant was not subjected to any adverse conditions during curing or storage. Yellowing will occur from direct exposure of stored hay to sunlight, cutting more mature hay, or exposure to rain during the curing process. Often, sun bleaching only affects the outside of bales, so look at the inside of a bale. If the hay is brown, it is mature, less nutritious and may be less palatable to horses. Yellow and brown plants have lower carotene content and palatability. Examples of the variation in colors is shown in the image below.
Color is a poor indicator of forage quality when considered alone, as bright green weeds may have lower nutrient composition than brown alfalfa. Don't pay a premium just because it is greener. Nutritionally, other variables are more important, such as the maturity of the plant.
Hay Should Be Free from Mold
Moldy hay most often occurs when hay is baled at high moisture levels (20% or more) without a preservative added. Look for visible mold and mold spores by inspecting a few bales of any purchased or stored hay. Mold spores create dust. Smell the hay. Some hays smell musty, but do not have visible mold. Hay should have a sweet smell indicating proper curing. Hay stored outside can be more susceptible to developing mold. Also, hay baled at a higher moisture level will have an increased risk of spontaneous combustion.
Hay Should Be Free from Foreign Matter or Weeds
- Look for foreign material in the hay. Hay and forages should be free of weeds. Weeds and wood often are less palatable, may be toxic, and may contain viable seed that will become a weed problem on your land.
- Look for coarse crop residue such as straw, corn stalks, and corn cobs that often are less palatable, and usually very low in nutritive value.
- Look for such things as plastic, manure, dead animals, and wire, which are harmful to animals and may affect palatability and aroma.
Use of Hay Stored for More Than One Year
Hay that is stored under cover and protected from sun and rain loses very little of its nutritional value. The amounts of energy, protein, calcium, phosphorus, and other nutrients and minerals decrease slightly during the first month or two of storage, and remain consistent even after two years of storage. The only significant loss is carotene (vitamin A), but the greatest loss of vitamin A occurs right after harvest. To prevent a vitamin deficiency, horses should receive supplemental vitamin A when feeding hay that has been stored for more than one year. The feeding of commercial grain mixes or balancers, supplemented with vitamins, easily fulfills vitamin requirements for horses. Remember, under no circumstances should old hay be fed if it has been compromised by dust, moisture, mold, or foreign objects.