Healthy pastures filled with dense, nutritive grasses can be excellent forage sources for horses. In fact, some horses can meet all their nutrient needs on good-quality pasture alone. The key to establishing good pasture, however, is planting the appropriate forage types.
During the University of Maryland (UMD) Extension’s healthy horse-keeping webinar series, pasture and forage specialist Amanda Grev, MS, PhD, described different forage types and how to select the best ones for your horse’s pasture.
First, make sure your pastures are well-managed. “No forage species will persist if continually overgrazed or mismanaged,” she said. “Good pasture requires good management, and that will be true no matter what forage species we have in our fields.”
Grev described the broad forage characteristics property owners need to understand when selecting a species.
Cool vs. warm season
As their names imply, cool-season forages do best in cool, wet climates (they grow best between 60-80°F), while warm-season forages thrive in hot, dry climates (75-90°F). Grev explained that cool-season forages grow mostly in the spring and fall and slack off in the summer. Warm-season forages do just the opposite—they grow mostly in summer.
Examples of cool-season forages include Kentucky bluegrass, timothy, orchardgrass, and tall fescue. Warm-season forages include Bermuda grass, bahia grass, big bluestem, and Indian grass.
“One of the things to consider when debating whether a warm-season or cool-season forage is appropriate is what part of the country we’re in,” Grev said. “Cool-season forages predominate the northern half of the United States, with warm-season forages in the southern half. Places like Maryland fall into that transition zone where we can have some warm-season and some cool-season forages.”
Grasses vs. legumes
The main difference between grasses and legumes is their nutrient content. Grev explained that grasses tend to be lower in protein and calcium, a little lower in caloric value, and higher in fiber than legumes. Legumes have a higher feed intake and higher digestible energy than grasses. Plus, livestock tend to prefer them.
“Another benefit of legumes is they are capable of fixing nitrogen,” she said, “meaning they can fix their own nitrogen from the atmosphere and require less fertilizer applied to the pasture.”
Looking at overall forage quality at similar stages of maturity, legumes are usually the highest and warm-season grasses the lowest, said Grev.
Perennials vs. annuals
Perennial forages such as Kentucky bluegrass, orchardgrass, timothy, and tall fescue grow back every year. They’re slower to establish and grow, however, than annuals. Grev recommended perennial species for permanent pastures.
Annual species such as annual ryegrass, wheat, oat, triticale, sudangrass, and millet, while quick to establish and fast-growing, must be replanted each year.
“Annuals might be useful additions to some of our perennial forages for a variety of reasons,” said Grev. “They can extend the grazing season earlier or later into the spring or fall. Annuals can also provide replacement pasture under emergency grazing situations (e.g., winterkilled forage, flooding, drought). They can also be useful for pasture renovation after overgrazing, neglect, or uncooperative weather.”
In any of these scenarios, property owners can plant one or more cycles of annual forages to provide growth, control weeds, and help alleviate soil compaction while transitioning back to perennials, she said.
Maturity is the greatest determinant of nutritional value, said Grev. Leafy forages in their vegetative state have higher energy and protein concentrations. “As those forages mature,” she said, “they get a little more stemmy, fibrous, and lower in overall forage quality.”
Forage growth characteristics fall under two main classes: bunchgrasses that grow in thick, tufted bunchs and sod-forming grasses that have lateral growth habits.
“The key difference between them is bunchgrasses don’t always spread into bare spots,” said Grev. “They’re going to continue to grow in that clump, whereas sod-forming grass is going to spread and fill in some bare areas.”
Sod-forming grasses can usually tolerate closer grazing than bunchgrasses, she explained. Bunchgrasses, however, are typically higher yielding and grow taller and thicker.
Grev described a variety of cool-season perennial forage options, which are the species most commonly found in temperate zone horse pastures, and their pros and cons.
Orchardgrass aka “The Class Favorite”
This bunchgrass is well-liked and widely used, said Grev. On the plus side, it’s:
- Has good regrowth with adequate fertility and moisture;
- Compatible with legumes and often grown in mixtures such as alfalfa/orchardgrass; and
- Relatively easy and quick to establish.
On the other hand, it’s:
- Sensitive to cutting height or overgrazing; because orchardgrass stores much of its energy in the bottom few inches of stem, continually cutting or grazing at too low a height can deplete those energy reserves, Grev explained;
- Sensitive to soil fertility;
- Sensitive to certain diseases; and
- Requires good management and can’t be used and abused.
Tall fescue aka “Mr. Persistent”
This bunchgrass that has some spreading ability is hardy and long-lived. Its benefits include being:
- Deep-rooted and long-lived;
- Tolerant of traffic and close grazing (“It can handle a little more grazing pressure or hoof traffic than orchardgrass,” said Grev);
- Adapted to a range of soil and climatic conditions; and
- High-yielding with good seasonal growth distribution.
Its downsides include being:
- Less palatable and not as high-quality as other forages.
- Toxic to pregnant mares if it’s endophyte-infected. This tall fescue type contains an endophyte that produces toxic alkaloids than can impair mare reproductive performance, Grev explained. Endophyte-free (which has no harmful effects on livestock but reduced plant vigor and longevity) and novel endophyte (researchers developed an endophyte that’s not toxic but still retains forage persistence and hardiness) types also exist.
Timothy aka “One Hit Wonder”
This bunchgrass is known for having a big flux of production in the beginning of year, then being less productive for the rest of the grazing season, said Grev. Its pros include being:
- Very palatable;
- Good-quality; and
- Relatively quick to establish.
- Little regrowth;
- Poor growth under hot or dry conditions;
- Being less competitive and shorter-lived than other species;
- Having a shallow root system; and
- Being easily weakened by frequent cutting or grazing.
Timothy is better suited for hay than grazing, Grev said.
Perennial ryegrass aka “Fair Weather Fan”
This bunchgrass thrives best in temperate climates. Its pros include:
- Being high-quality;
- Being very palatable;
- Having good yield; and
- Establishing rapidly with good seedling vigor.
On the downside, it can be short-lived and doesn’t tolerate drought or high temperatures.
Kentucky bluegrass aka “The Turf Builder”
This dense sod-former has great ability to fill in bare spots. It’s also:
- High-quality; and
- Less sensitive to close or frequent grazing.
Kentucky bluegrass is low-growing and not as productive or high-yielding as other species, said Grev. It also goes dormant during hot or dry periods.
Smooth bromegrass aka “Slow and Steady”
This sod-former can be difficult to get established, but once you do, it’s very persistent, she explained. Its benefits include being:
- Good-quality; and
- Fairly hardy and able to survive periods of drought and temperature extremes.
On the other hand, it’s slow to establish, produces uneven yield distribution, and experiences poor growth during hot or dry conditions. Smooth bromegrass is better suited for hay than grazing, said Grev.
Reed canarygrass aka “The Pool Boy”
This sod-former is known for its ability to grow well in wet areas. Its pros include being:
- Persistent once stable; and
- Drought- and flood-tolerant.
Grev said it’s slower and more difficult to establish than other species, however, and can be stemmy and less palatable when mature.
Alfalfa aka “Queen of Forages”
This high-quality legume boasts excellent productivity. Its many benefits include being:
- Very palatable;
- Highly productive;
- Long-lived; and
- A good summer producer.
One of alfalfa’s downsides is it requires good soil fertility with high pH levels and good drainage. Therefore, it can be more difficult and expensive to establish, said Grev. Still, she maintained that it’s one of the best forages from a quality and production standpoint.
Red clover aka “Red-Headed Stepchild”
This legume is “usually perceived as being a step down from alfalfa but can be a great forage option,” said Grev. Property owners like it because it’s:
- Easy to establish;
- Quality and yield are good;
- Very palatable; and
- More tolerant of acidic or poorly drained soils than alfalfa.
It’s shorter lived than alfalfa, however, with a stand life limited to two or three years.
White clover aka “Old Faithful”
This legume is seemingly everywhere, said Grev, and tends to stick around. Its pros include being:
- Easy to establish;
- Very palatable;
- Able to grow well in mixtures; and
- Grazing tolerant.
Its cons include being:
- Lower-yielding than red clover or alfalfa; and
- Susceptible to shading, which occurs when taller forages shade out the clover below. For this reason, Grev recommended planting Ladino, which is a larger, taller-growing type of white clover.
Forage Chicory aka “Popeye’s Pick”
Not to be confused with the tough weed form of chicory, this forb is good-quality and resembles spinach leaves, said Grev. Its benefits include being:
- Drought-tolerant; and
- A good summer producer.
Grev said it can also have anthelmintic (antiparasitic) properties for ruminants. On the downside, forage chicory is:
- Prone to bolting, when tall stems grow up out of the base growth of forage;
- Better on well-drained soils; and
- Shorter-lived than other species.
Grev said forage chicory is increasing in popularity as a pasture forage and is better-suited for grazing than haying.
She did not delve into warm-season perennial pasture species because they’re less common in the temperate zone. Examples, however, include Bermudagrass, bahiagrass, big bluestem, eastern gamagrass, Indiangrass, switchgrass, and little bluestem.
Grev said the most common cool-season annuals for horse pastures are:
This species is very palatable, high-quality, easy to establish, has good seedling vigor, and grows rapidly. It provides fall and early spring forage, Grev said, and can be interseeded if needed to fill in bare areas. Ryegrass, however, can be overly competitive in mixtures and not very tolerant of drought or high temperatures, she added.
Cereals such as barley, rye, wheat, and triticale have good quality and yield and are easy to establish. Grev said they provide fall and early spring forage and can be grazed at early maturity or harvested later. She cautioned that cereals vary greatly in their cold tolerance, quality, and rate of maturity.
A couple of popular warm-season annual pasture forages include:
This species is tolerant of drought and acidic soils, easy to establish, and has no prussic acid concerns like some other warm-season annuals do. On the other hand, it can grow quite tall, has a larger stem size, and is subject to nitrate accumulation. Grev recommended looking for dwarf varieties that are shorter, leafier, and better-suited for grazing. When grazing or mowing pearl millet, she said you must leave 6-10 inches of stubble for regrowth, which is more than most other species.
Teff is palatable and fine-stemmed with a high leaf-to-stem ratio, said Grev. It’s good-quality, heat-and drought-tolerant, grows rapidly once established, and has no prussic acid or nitrate toxicity concerns. It can be difficult to establish, however, due to its small seed size and low seedling vigor. Teff is also sensitive to cool soils or frost, as well as overgrazing and low cutting heights. “It’s a little trickier but a good option if you can make it work,” said Grev.
Newer forage varieties of crabgrass are quite suitable for grazing, she explained. They’re productive, good-quality, leafy, grow rapidly, will reseed if allowed, relatively drought-tolerant, tolerant of acidic soils, and have no prussic acid or nitrate toxicity. Their small seed size, she noted, can make planting difficult.
Now that you’ve reviewed all your forage species options, how do you choose one or more to seed your field with?
First, said Grev, match plants to soil and site characteristics, including your soil type, drainage, moisture holding capacity, fertility, pH levels, and topography. Then match plants to intended use. Will you use your fields for hay or grazing? Do you need permanent (perennial) or temporary (annual) growth? What time of year is it (cool- vs. warm-season)? What type of pasture management system (e.g., grazing pressure) do you have?
Also match plants to the type of horses on your property. A nursing mare or hard-working horse, for instance, will need a higher relative forage quality than an idle or lightly working horse.
“Consider soil and land characteristics, management strategies and goals, and animal needs,” said Grev. “Then choose one or a couple of appropriate base forages. Include a mix of forage types (i.e., grass and legumes).”
Choose a high-performing variety for your climate and terrain. “Look at variety trials conducted at universities in your area (e.g., the University of Kentucky, Penn State) where they’ve tested these various forage types under difference conditions to see how they’ve performed,” Grev suggested.
To review, Grev’s considerations for pasture forage selection include:
- Soil type and characteristics, such as drainage, fertility, and soil pH;
- Amount of land and topography/slope of that land. “Some do better in low-lying wetter areas, while others are more persistent on steeper slope areas,” she said;
- Intended use of that pasture (e.g., hay vs. pasture, permanent vs. temporary, time of year, length of grazing season, management system, etc.);
- Animal species, class, and number; and
- Disease or insect pressure, as some varieties are more adapted or resistant to those pressures than others.
Your local extension office or ag agent can help you identify pasture forage species that are suitable for your region and property.