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Selecting and storing horse hay
Plants have more fiber and less protein as they mature.
Don’t be too concerned about hay color. All hay needs mineral and vitamin supplementation.
You can feed quality, rained on hay to horses.
Horse quality hay should be baled between 10 and 15 percent moisture.
Store and protect hay from moisture to best prevent spoilage.
The digestive system of the horse has been designed to efficiently utilize forages, and most horses can fulfill their nutrient requirements on these types of diets. You should choose your forage based on your horse’s nutrient needs. A variety of factors, including plant species and maturity should be considered when making this decision.
Legumes and cool-season grasses are common horse forages. Know what percent grass and legumes are in your hay before buying it. Average nutritive values of forages commonly fed to horses are shown in table 1.
Legumes include alfalfas and clovers. They generally produce a higher quality forage than cool-season grasses when baled at the same growth stage. Compared to grasses legumes are,
Higher in energy
Higher in protein
Higher in minerals (calcium)
Lower in nonstructural carbohydrates (starches and sugars)
Usually more palatable
Usually more digestible
Legumes provide horses an excellent source of nutrients, but feeding pure or immature legumes can easily exceed a horse’s nutrient needs. Excess nutrients can lead to obesity. Legume-grass mixes or mid- to late-maturity legumes (less nutrient-dense) often provide adequate nutrients, without exceeding the horse's needs.
Alfalfa has more protein than grasses, which is highest in the leaves. As the plant matures, the protein content declines. Excess protein doesn’t affect the horse’s health but will increase their water needs. Thus, horses will urinate more and excrete more ammonia.
Some legumes are hard to dry (like red clover) when making hay, and thus have a higher risk of molding.
Cool-season grasses are grasses that thrive in cooler, wetter climates. They are popular in the Midwest and grow best in the spring and fall. The following are common cool-season grasses found in horse hay and pastures:
Compared to legumes, grasses are,
Lower in protein
Lower in calcium
Less calorie dense
Higher in nonstructural carbohydrates
Table 1. General nutrient characteristics of forages commonly fed to horses
|Digestible energy (Mcal/kg)||1.7-2.5||2-2.5|
|Crude protein (%)||6-18||14-26|
|Neutral detergent fiber* (%)||55-65||35-45|
|Acid detergent fiber** (%)||30-40||30-40|
*Neutral detergent fiber relates to palatability (lower value indicates more palatable)
**Acid detergent fiber relates to digestibility (lower value indicates more digestible)
The maturity of a plant affects forage quality. Young, immature plants are nutrient dense and contain less fiber. As the plant matures, the proportion of fiber in the plant increases. This can decrease plant digestibility.
Most horses do well on mid-maturity forages. Horses that require higher nutrient needs (e.g. lactating mares) benefit from young, less mature forages. More mature forages are a good choice for easy keepers.
The following indicate a more mature plant:
Flowers in legumes
Seed heads in grasses
Grasses harvested just as the seed heads start to form have excellent fiber digestibility and energy availability, and will produce leafy hay.
The leaf to stem ratio of a plant is also key. As a plant matures the leaf to stem ratio declines. Compared to stems, leaves have,
More digestible energy
Less fiber than stems
A horse’s mouth, lips and tongue are very soft. Thus, they will be more willing to eat softer hay and in turn, waste less. Even if the hay has good nutritional value, it must be appealing to the horse otherwise they’ll waste it.
Sweet smelling hay is appealing to people and horses and indicates available energy (sugar). A sweet smell is an incentive for the horse to eat the hay and get its full nutritional value.
Green is appealing to horse owners and indicates the presence of vitamin A. Bleached color indicates exposure to sunlight or rain. In this case, vitamin A content is lower, but other essential nutrients still remain.
Despite the color, you must supplement any hay with an appropriate vitamin-mineral mix.
Don’t be too concerned about color. Remember, weeds are also green in color.
You can feed quality rained on hay to horses.
Hay quality declines the most when rain occurs after the forage has partially dried. Alfalfa dry matter declined 22 percent when exposed to an inch of rain after one day of drying. Similar hay without rain damage lost only 6.3 percent.
Rain (or soaking hay in water) can reduce the nonstructural carbohydrate (i.e. sugar) content of the hay. Good quality, rained on hay can benefit horses that are sensitive to forage sugar content.
The cutting (1st, 2nd or 3rd crop) doesn’t predict the hay’s nutrient content. Maturity at the time of cutting is the basis of the hay’s nutritional value.
Plants that grow under cooler temperatures build more digestible fiber. Thus, 1st crop hay may have more and easier to digest fiber.
Horse quality hay should be baled between 10 and 15 percent moisture.
Hay baled over 17 percent is at risk of molding.
Hay baled over 25 percent is at risk of severe heat damage and serves as a potential fire hazard.
Using propionic acid can help prevent molding at the time of baling. Producers commonly use it when the hay is between 17 and 25 percent moisture. Propionic acid-treated hay may smell slightly acidic, but is safe for horses.
Don’t feed horses moldy hay.
Nearly all feed has some mold spores. Excessive mold may cause coughing, heaves or allergic reactions if horses inhale it. Horses with heaves are often more sensitive to mold spores or dust.
Always inspect the inside of at least one bale before buying the hay. Hay stored inside that isn’t moldy has a low risk of getting moldy.
Hay can be baled in a variety of ways. Depending on your storage and feeding methods, each type has pros and cons.
Small square bales (40 to 80 pounds) are easy to handle and store. Horse owners commonly use this bale type. When fed and stored properly, small square bales usually have less waste than round bales and medium or large square bales.
Small square bales can be very labor intensive.
Horse owners also commonly use round bales (800 to 1,200 pounds). Due to their size, a tractor or skid steer is needed to move round bales.
Round bales can be less labor intensive than small square bales. But when stored improperly or fed without a feeder, round bales can result in excessive hay waste. Having enough horses (i.e. more than one) feeding off a round bale will reduce waste during feeding.
Medium or large square bales (800 to 1,200 pounds) gained popularity with horse owners over the past few years. They have the same pros and cons as round bales. But medium or large square bales tend to stack better and “flake” off easier for individual feeding than round bales.
Out of state hay needs
The certified noxious weed seed-free forage program assures that certified forage meets the minimum standards to limit the spread of noxious weeds. Minnesota doesn’t require you to use certified hay. It’s voluntary for you to use certified hay when trail riding and camping in Minnesota public parks.
If you plan a trail ride or camping trip with your horse on public lands in the western U.S., you must use certified hay.
Contact the Minnesota Crop Improvement Association for a list of producers of certified noxious weed seed-free forage in Minnesota: 800-510-6242.
Tips for storing hay to maintain good condition and reduce losses.
Don’t stack your hay under a leaky roof. It will grow moldier with each rain.
Plug rat and mouse holes.
Detour larger wildlife such as raccoons from moving in during the winter months.
Animals will make a mess of your hay storage by depositing feces and chewing through twine. Droppings from some wildlife can cause diseases in horses like EPM (equine protozoal myeloencephalitis).
Stack bales on pallets to allow air flow under the bales and to help prevent the hay from absorbing ground moisture. Hay bales stored on wet surfaces can have as much as 50 percent spoilage.
Hay should keep indefinitely if:
Moisture can’t enter the bale from any direction
The hay was dry when put it into storage
High humidity can increase moisture content and reduce storage life. Thus, we recommend feeding hay within two years of purchase. Regardless, it’s good practice to always use older hay first.
Storing round bales end-to-end will reduce waste when stacked outdoors. Stacking large round bales usually increases losses, especially when stored outside. Stacking tends to trap moisture and limits drying from the sun and wind.
Studies show that outside storage loss for round bales ranges between 5 to 35 percent (see table 2) depending on the following;
The amount of precipitation
Storage site location
Original condition of the bale
To reduce this loss:
Buy tightly packed bales.
They will sag less and make less contact with the ground.
Buy bales with net wrap.
They will resist weathering, insects and rodents better than natural twine fibers.
Store bales on a well-drained site (if outside).
Never store round bales under trees or in low lying areas.
Cover any bales you store outside. Tarps work well.
The outer 4-inch layer of a 6-foot diameter round bale contains about 25 percent of the total bale volume. This is subject to damage by weather without proper storage or cover.
A good plastic cover can reduce storage loss by one-half.
Storing round bales inside can reduce storage loss by about two-thirds.
Table 2. longevity of stored hay
|Hay Storage Options||Storage Longevity (Years)||Dry Matter Loss (%)|
|Tarped on Pallet||5||4-7|
|Net Wrap on Ground||1||15-25|
|Twine on Ground||1||25-35|
Hay tests determine the contents of hay such as:
Be sure to request an equine analysis and remember that the analysis is only as good as the sample you submit.
Reviewed in 2018