Horses require 2 to 3 percent of their bodyweight in feed each day.
At least half of their daily feed intake should be in the form of roughage such as fresh forage or hay to optimize digestive health.
The amount and type of hay a horse needs ultimately depends on the individual horse’s nutrient requirements and the quality of the hay. Hay quality should be determined by laboratory analysis and visual assessment.
Why do you need to know this? As horse hay suppliers, you should be aware of ways to best match your hay with your clients’ needs. Here are a few examples:
Example 1: Adult horse (not exercising, not reproducing)
The nutrient requirements of non-exercising, non-reproducing adult horses can be met by good-quality grass hay alone.
Hay should be analyzed for nutrient content to identify any deficiencies. A vitamin and mineral mix should be offered.
• Horse weight: 1,000 lbs
• Required daily feed intake: 2 percent bodyweight
• Total intake per day: 20 pounds
• Percentage of hay in daily ration: 100 percent
• Percentage of concentrate in daily ration: 0 percent
• Amount of hay required in daily ration: 20 pounds
• Amount of concentrate required in daily ration: 0 pounds
Example 2: Working horse –Moderate exercise (three to five hours each week)
The nutrient requirements of working horses are determined by the intensity and duration of exercise. To meet the increased requirements of working horses, cereal grain-based concentrates are often included in the daily ration.
Following is an example of a feeding program including hay requirements to meet the needs of a horse in moderate exercise.
• Horse weight: 1,000 pounds
• Required daily feed intake: 2 percent bodyweight
• Total intake per day: 20 pounds
• Percentage of hay in daily ration: 75 percent
• Percentage of concentrate in daily ration: 25 percent
• Amount of hay required in daily ration: 15 pounds
• Amount of concentrate required in daily ration: 5 pounds
Grass hay alone may not be sufficient to meet the needs of working horses. Alfalfa hay is typically higher in digestible energy and nutrients and may be sufficient in meeting the needs of working horses, particularly those in light or moderate work.
Example 3: Growing horses (12 months old)
The energy and nutrient requirements for growing horses are greatly influenced by their stage and rate of growth.
• Horse weight: 700 pounds
• Average daily gain: 1 pound
• Required daily feed intake: 2 percent bodyweight
• Total intake per day: 14 pounds
• Percentage of hay in daily ration: 75 percent
• Percentage of concentrate in daily ration: 25 percent
• Amount of hay required in daily ration: 10.5 pounds
• Amount of concentrate required in daily ration: 3.5 pounds
Good-quality grass hay, alfalfa and grass/alfalfa mixed hays can be used in feeding programs for young growing horses due to their higher protein requirement and the higher protein content in legumes and immature grasses.
Equine forage quality guidelines
Most universities and equine nutritionists encourage horse owners to have their hay or pasture analyzed, especially if the quality of hay is a concern or the horse is having nutritional problems.
However, most horse owners need help interpreting the results of their analysis. Below is a list of some common components analyzed in hay and a basic interpretation of each.
Keep in mind that additional components can be analyzed for by request and/or for an additional cost.
When your sample is returned, there will be two columns of numbers: “as sampled” and “dry matter.” As sampled reports nutrients in their natural state; this includes moisture.
Dry matter reports nutrients with the water (moisture) removed. Results reported as dry matter allow for the direct comparison of nutrients across different feeds and often simplifies the ration-balancing process.
Either can be used for ration balancing, but it’s very important to be consistent and use one or the other.
• Moisture: The optimum horse hay moisture ranges from 10 to 15 percent. Hay under 10 percent may be too dry, leading to brittle and dusty hay.
Hays over 17 percent moisture have a high probability of molding (unless propionic acid is used), and hays over 25 percent moisture pose the threat of severe heat damage and serve as a potential fire hazard.
• Dry matter (DM): Amount of the sample left after the water (moisture) is removed.
• Crude protein (CP): A measure of the protein concentration in the hay. CP can range from 8 to 14 percent in grass hays (depending on nitrogen fertilization), 14 to 17 percent in mixed hays and 15 to more than 20 percent in legume hays.
Hay containing approximately 10 percent CP meets the CP requirements of most horses, lactating mares and foals being the exception.
• Acid detergent fiber (ADF): ADF primarily represents cellulose and lignin, the highly indigestible fractions of plant material.
The lower the ADF value, the more digestible the nutrients in the hay are. Hays with ADF values of 30 to 35 percent are readily digested, while those above 45 percent are appropriate for feeding horses with lower energy needs.
• Neutral detergent fiber (NDF): NDF is a measurement of the insoluble fiber, including hemicellulose, cellulose, ligno-cellulose and lignin.
These components are classified as cell wall or structural carbohydrates and provide the plant with structural rigidity. The higher the NDF, the less a horse will consume.
NDF levels between 40 and 50 percent are good, while those above 65 percent will likely not be readily consumed by most horses but can be used as “busy hays” to pacify obese horses on restricted feed.
• Relative feed value (RFV) or relative forage quality (RFQ): RFV and RFQ are commonly used when selecting quality dairy hay but are not used in balancing equine rations.
However, RFV and RFQ can be used as a guideline in identifying quality hay. Generally speaking, higher RFV and RFQ reflect higher quality, greater intake and digestibility.
• Fat (sometimes referred to as crude fat): This is a measure of fat content. Fat is an energy-dense nutrient and contains about 2.25 times the energy found in carbohydrates. Forages are typically low in fat.
• Non-fiber carbohydrate (NFC): This is a mathematical estimate of starches and sugars. Although not always perfect, the NFC value is often used as an indicator of the level of starches and sugar in a forage sample.
• Equine digestible energy (DE): This is a measure of the digestible energy in the hay and is used to balance the energy portion of the equine diet.
For a light-working horse, DE intake should be approximately 20 Mcals per day; most hays range from 0.76 to 0.94 Mcals per pound of DE.
• Equine total digestible nutrients (Equine TDN): This is a measure of the total digestible nutrients in the hay or its energy value (may be used in place of DE, or offered in addition to DE), which may range from 40 to 55 percent.
• Calcium (Ca) and phosphorus (P): These two macrominerals are required in the diet by all horses in specific amounts.
The levels of these minerals can vary among different types of hay; for example, legume hays have high calcium levels relative to phosphorus. For the adult maintenance horse, the Ca:P ratio should be between 3:1 to 1:1.
• Potassium (K): This is an electrolyte. Legume forages are higher in potassium than grasses. Since hay is generally high in potassium, and usually constitutes a significant portion of the equine diet, potassium requirements are usually met with hay alone.
Recently, there has been significant interest in the sugar and carbohydrate content of hays. The below analyses can be very useful in selecting a suitable feed for horses, especially those that show sensitivity to carbohydrates.
Some labs test for the following (note there may be an additional charge for these services):
• Non-fiber carbohydrate (NFC): Discussed above.
• Non-structural carbohydrates (NSC): This is an analysis of the non-structural carbohydrates (starches and sugars) in the forage.
Not to be confused with NFC, which is estimated, not measured directly. Sometimes, NSC is estimated by adding starch plus either WSC or ESC.
Since some horses can be very sensitive to dietary starch and sugar (i.e. horses with Cushing’s disease, PSSM or laminitis), the NSC level can be helpful in selecting hay. Hay containing greater than 10 percent NSC should not be fed to these horses.
• Starch: This is a good source of energy. However, no more than 15 percent of total daily calories from starch should be fed to horses diagnosed with PSSM (polysaccharide storage myopathy).
• Ethanol-soluble carbohydrates (ESC): Carbohydrates solubilized and extracted in 80 percent ethanol. Includes primarily monosaccharides (glucose and fructose) and disaccharides. Some forage labs will refer to ESC simply as “sugar.”
• Water-soluble carbohydrate (WSC): Carbohydrates solubilized and extracted in water. Includes monosaccharides, disaccharides and some polysaccharides (mainly fructan). Fructan is a major storage carbohydrate in grasses.
Subtracting WSC from ESC will give a rough estimate of fructan. Use only with cool-season grasses. Fructans is a complex sugar correlated with laminitis.
Balancing your horse’s ration
Once your hay has been analyzed, work with an equine nutritionist to balance your horse’s ration. Generally speaking, a horse’s ration is balanced in the following order: energy (with a focus on fiber), protein, minerals and vitamins.
Horse hay marketing tips
When marketing horse hay, try to:
• Remember that quality forage should be the backbone of a horse’s diet. Forage should be a minimum of 50 percent of their nutritional needs, and some horses’ energy requirement can be met with 100 percent hay.
• Have a good working relationship with your clients. Allow them to ask several questions and be patient as they learn about hay.
• Convince your clients to buy hay early (do not wait until late summer or fall), add additional hay storage space and to plan in advance (especially if the price is rapidly changing).
First-crop hay is an excellent choice for horses, and the fiber in earlier cuttings tends to be more digestible.
• Keep your clients’ hay type (i.e. grass or alfalfa) consistent. Constantly changing hay types can lead to horse health problems, specifically colic.
• Have your hay analyzed so you can match the needs of your clients with your hay. FG
J. Earing, Ph.D. and C. Sheaffer, Ph.D., both of the University of Minnesota, contributed to a portion of this article.
References omitted due to space but are available upon request. Click here to email an editor.
—Excerpts from University of Minnesota Forage Days newsletter and University of Minnesota Extension fact sheet
Krishona Martinson
Equine Extension Specialist
University of Minnesota
