Make informed forage decisions that satisfy each horse’s nutritional, health, and welfare needs

Joël Lecomte shuts off the roaring engine of his tractor and steps down onto the outer edge of a vast, grassy, practically treeless meadow. On this unseasonably warm spring day in Central France, the soon-to-be-retired farmer looks up at the clear sky, takes off his beret, and wipes his brow with his shirt sleeve. Ever a man of few words, he pinches off a blade of bright green ryegrass and simply says, “For the horses, it can’t wait. We’ll cut tomorrow.”

Like all producers of good-quality hay, Lecomte knows there’s an art to growing the right forage for the right herbivore, and hay is anything but one-size-fits-all. Everything matters, from seeding and fertilizing methods and the blend of plant species in the field to the amount of sunshine, rainfall, frosty mornings, wind, and hail and the timing of cutting, drying, and baling.

Unless they cut their own hay, most horse owners don’t need the expert skill set it takes to produce good forage. But what we can—and should—do is know how the quality and nutritional value of forage can vary considerably from one batch to another. And, armed with that knowledge and the help of our equine nutritionists, we can make informed decisions about choosing the right forage for our horses’ needs, says Emanuela Valle, DVM, PhD, ECVCN, head of the clinical nutrition counseling group in the University of Turin’s Department of Veterinary Science, in Italy.

Matching Nutrients to Horse, in a 2% Format

High-quality forage is chock full of nutrients; it can essentially supply all the calories, protein, calcium, phosphorus, and potassium horses need, as well as most of the magnesium and iron and many other vitamins and minerals, says Shannon Pratt-Phillips, PhD, a professor of equine nutrition in North Carolina State University’s Department of Animal Science, in Raleigh.

“A lot of times people overlook the importance of hay as a nutrition source,” she says. “They just think, ‘I’m just going to give some hay (as a filler) because he’s getting everything he needs from the grain. But it should be the other way around: You should get as much as you can from the hay and whatever’s missing from complementary feed or a balancer.”

Even so, you wouldn’t want to give the same amount and balance of those nutrients to every horse, whose needs vary depending on size, body condition, breed, discipline, work level, genetics, general health, and more.

What you do want to give every horse is the opportunity to spend about 75% of their day consuming and chewing forage, our sources say. This is good for their ­welfare—because grazing all day is what they’re designed by nature to do—and their digestive tract, which is designed to have a fairly constant flow of fiber and saliva enzymes running through it.

Ideally, horses on a hay diet should eat about 2% of their body weight in forage every day. For wetter and dryer forages (see section below), that amount would need to increase or decrease accordingly. Less than that, horses might feel deprived; more than that, they might not finish it all. 

That said, if horses need to lose weight but don’t have access to a good-quality, ­lower-nutrient forage, owners can temporarily drop the ration down to 1.75% or even 1.5%, Valle and Pratt-Phillips say. In such cases, using slow feeders to drag out the consumption time is critical for horses’ health and welfare.

Because you want to neither overfeed nor underfeed nutrients, it’s important to adjust the balance of those nutrients within the daily ration by choosing the right hay for each horse.

Stored Forage Basics

Horses can get fresh forage from pasture grass and other vegetation, such as trees and bushes, but that goes beyond the scope of this article. Instead, we’ll take a closer look at the different kinds of stored forage. Here’s a quick rundown on stored forage terms:

• Hay Sun-dried forage with less than 20% water content, cut from fields of grasses and/or legumes planted and cultivated for animal consumption.
• Haylage Wet, slightly fermented forage wrapped in plastic, with a water content of about 50%.
• Silage Wet, fermented forage wrapped in plastic, with a water content of about 80%.
• Cubes and Pellets Sun-dried or dehydrated forage chopped and pressed into dense, dry cubes or pellets and packaged in commercial bags.
• Chaff Loose, chopped sun-dried or dehydrated forage packaged in commercial bags.
• Straw Sun-dried hollow stalks of grain plants such as wheat, oats, and barley.

Fermented forages often contain variable levels of water-soluble carbohydrates, Valle says. And because they include so much water, horses must eat larger quantities of haylage and silage than hay to get the equivalent in dry matter—which can be more than some horses can consume in a day.

Chopped forage usually creates less waste because, unlike with long-stem forage, horses aren’t selectively picking the shorter strands. It’s a particularly good option for older horses that have difficulty chewing, our sources say. Plus, chopped forage often requires less storage space because it’s so dense. However, it can be expensive and might need to be soaked prior to serving to senior horses with dental issues.

Straw can be an excellent forage for equids needing extremely low carbohydrates and calories, such as obese horses and ponies as well as donkeys, because it offers low-nutrient chewing time, says Valle (though you might need to feed those animals a ration balancer, as well, to be sure they are getting the base vitamins and minerals they need). For nonobese animals, straw should make up no more than 30% of forage intake, she adds.

All forage should be free of obvious dust, mold, toxic plants, and trash. They should also not contain dead animals (i.e., mice and other field-dwellers), which can cause botulism, Pratt-Phillips says. Alfalfa, in particular, should be free of blister beetles that burrow into the stalks, as “they’re quite deadly in small amounts,” she explains. Examine alfalfa hay for blister beetles closely before feeding, buy earlier cuts to reduce likelihood of infestation, and cultivate a good relationship with a local hay producer whose production practices you trust. Except for straw, forage should be leafy, without too many stems, and have a pleasant odor and a pale to bright green color.

Forage generally contains some degree of dust, which—even when difficult to detect—can be problematic for asthmatic horses, says Valle. To reduce dust, owners might steam or soak the forage in water first.

Cool-Season Grasses, Warm-Season Grasses, and Legumes

Good-quality forage contains any of three categories of plant species: cool-season grasses, warm-season grasses, and legumes.

Cool-season grasses, like orchardgrass, Kentucky bluegrass, ryegrass, and timothy, generally grow from early spring to early winter. They usually offer high levels of nutrients, including nonstructural carbohydrates (NSCs), says Jennifer Weinert-Nelson, PhD, of the Department of Animal Sciences at Rutgers, The State University of New Jersey, in New Brunswick.

Warm-season grasses, such as ­Bermuda and modified crabgrass, grow only during warmer seasons and generally in lower-latitude zones, which do not include the upper Northeastern United States or Northern Europe. However, genetically modified versions are now successfully growing in higher latitudes, Weinert-Nelson says. These grasses offer the benefit of up to 60% lower NSC concentrations than cool-season grasses, she explains.

Warm-season grasses also tend to be more resistant than cool-season grasses to dry conditions, and they grow faster and produce more forage mass, says Valle.

However, warm-season plants can be risky, she adds. They can store toxic substances such as the cyanogenic glycoside dhurrin. Thus, they might not be an ideal base forage. “Always buy hay made from cold-season grasses,” she says. “But if you want to buy warm-season plants like sorghum, do your research and ask for validation by experts first.”

Legumes are the plant family that includes soybeans, chickpeas, lentils, and ­peanuts—as well as clover and alfalfa. Legumes are known for their ability to “sequester nitrogen,” leading to high protein content—in general 50% more protein than grass hay, Pratt-Phillips says. They also offer higher calcium levels than in grass hays, which can sound good, except they don’t also offer higher phosphorus levels. An incorrect calcium-phosphorus ratio can lead to negative health consequences. Plus, legumes contain such high nitrate levels that horses often drink and urinate more to eliminate the excess.

Legumes such as alfalfa hay might be good forages for horses with high protein requirements, including those in intense exercise or broodmares, says Pratt-Phillips. But that richness can have drawbacks, such as causing young horses to grow too fast and develop osteochondrosis or other bone disorders, she says.

Despite the temptation to opt for high protein, owners should consider balancing out legumes with grasses. Many hay producers offer mixes of grass hay combined with 25% or 50% alfalfa hay for people looking for that extra punch for their horses. “Very few horses need a 100% legume hay,” she says. “A straight legume hay is usually overdoing it.”

Why Cut and Storage Time Matter

Young plants are full of protein, which helps them grow, says Pratt-Phillips. As they mature, the balance shifts to less protein and more fiber, which helps them stay upright as they get taller. That’s why Valle says she prefers a first-cut meadow (from permanent, usually natural grasslands) hay for sport horses, which is “usually quite leafy” if cut at the beginning of the hay season (e.g., early May).

The reality, however, is when producing forage, it’s not just about cutting a plant but an entire field that often includes multiple species, all growing at different rates, under different weather conditions that can affect growth, Pratt-Phillips explains. The mix might even include a few weeds that tend to pop up during certain parts of the year. “The ‘cut’ depends on what plants are growing in the field and when they’re going to be in a more advanced growing stage,” she says.

It’s also important to consider how long the forage has been stored, Valle adds. Ideally, it should be consumed within a year, after which its nutrients start to diminish considerably, even when stored properly. By contrast, haylage and silage that’s been stored less than 60 days should never be fed to horses, because its fermentation process has not yet stabilized, she says. 

Markets and Lab Tests

Getting the minute details about the species mix, weather conditions, storage conditions, and other data about your forage options can be an overwhelming task, our sources say. Fortunately, professional organizations and hay dealers can comb through those issues for owners and make recommendations based on buyers’ specific needs.

“A good hay dealer should ask you, ‘What kind of horse do you have?’ and know about a forage’s nutritional quality based on maturity and species,” Pratt-Phillips says.

Some owners might opt to buy directly from producers, who should be able to talk knowledgeably about the fields they’ve cut. With experience, owners can learn to recognize forage types by the look of the forage itself—leafiness, stem size, and plant species.

But even professional nutritionists can’t always accurately judge nutritional quality just by seeing the bale, Pratt-Phillips says. That’s why lab testing is such an important tool. At around $10 to 15 per sample, forage analyses can take away the guesswork and provide specific nutritional data to help you ensure you’re feeding each horse appropriately for his or her needs.

Whether you buy from the farm or from a dealer, be sure to check the business’s reputation, our sources say. “The only way these places survive is because people come back and buy hay from them again,” Pratt-Phillips says. “They build their reputation based on the quality of their hay and their knowledge.”

Take-Home Message

Forage producers create a wide variety of choices for horse owners—and for good reason. Not all hays and other stored forages are appropriate for all equids. With a stable knowledge base, though, owners can make informed decisions about forage that satisfy each horse’s nutritional, health, and welfare needs.