Forages as hay or pasture make up the significant share of the daily intake of a horse. Horses are natural grass eaters with front teeth suited for biting off the grass. The molars chew and grind bulky feed, such as hay and coarse grains. A mature horse that is not working hard will eat 1.5 to 2 pounds of air-dry feed per 100 pounds of body weight. That would be 15 to 20 pounds of hay daily for a 1,000-pound horse. In Iowa, horses will require about 2 tons of hay per head per year, plus summer pasture. When meeting nutrient requirements, carefully consider forage quality and nutrient content.
Pasture is the ideal forage for horses in spring, summer, and fall. In winter, high-quality hay is the essential winter feed for horses. Hay furnishes energy, protein, and bulk. Mature, idle horses can get along on good hay and mineral supplement alone. Supplementing with grain may be necessary if hay quality is poor. Growth, work, and reproduction also may require that rations include grain supplementation.
Iowa hay ranges from all legume to all grass, with many different proportions of legume‑grass mixtures. With a sound ration formulation, nearly any medium-to-high-quality hay is suitable. The following provides information on the types of legumes and grasses grown in Iowa for pasture and quality hay for horses.
Alfalfa
Alfalfa is the most common legume fed to horses. Figure 1 provides the characteristics of alfalfa. It is the highest yielding legume and generally will persist for four to six years. It is primarily hay because alfalfa grows very erect. Alfalfa also is a good grazing crop, but will be too rich in nutrients, especially energy and protein, for most horses unless mixed with about 50% grass. It can be dually used for hay in the spring and grazing after that. It requires a soil pH of 6.8 or higher and does not do well in poorly drained soils.
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| Figure 1. Alfalfa Characteristics. Photo provided by ISU Department of Agronomy |
Red Clover
Red clover is a fast-growing legume with high yields. Characteristics of red clover are shown in Figure 2. The soil pH should be 6.2 for the best growth. When choosing seed, many varieties exist. Higher quality types will last four years in the pasture, while cheap types only last two years. It is possible to frost seed this into grass pastures in most parts of Iowa. In horses, red clover will cause slobbering, and many horse people avoid feeding the legume.
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Figure 2. Red clover characteristics. Photo provided by ISU Department of Agronomy |
White Clover
White clover is the most common clover in pastures. See Figure 3. It is easy to establish and is the most drought tolerant. It also is the most tolerant when overgrazing occurs. White clover spreads by above-ground runners called stolons. Current white clover variety selection by producers favor the Ladino clovers and “Large leaf” New Zealand type. These are the better yielding white clovers, but not quite as good on persistence as the Dutch white clovers or common white clovers. However, the Dutch and common white clovers are smaller leafed, lower-yielding, and not as good of a choice for pastures. White clover also causes a horse to slobber or produce excess saliva.
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Figure 3. White clover. Photo provided by ISU Department of Agronomy |
Birdsfoot Trefoil
Birdsfoot trefoil is a long-lived legume that reseeds naturally. It is high in quality and maintains its quality longer than most other legumes. Thus trefoil is useful for stockpiling (i.e., allowing it to mature and save it for periods of drought or late fall/early winter grazing). It tolerates wet conditions. Figure 4 shows the characteristics of Birdsfoot trefoil.
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| Figure 4. Birdsfoot Trefoil. Photo provided by ISU Department of Agronomy |
Cool-season grasses grow well in northern states and are excellent for grazing. These start growing early in the spring and produce the bulk of their growth in May and June. Some cool-season grasses will continue to provide excellent forage through the summer and fall if fertilized with nitrogen fertilizer in June and August.
Cool-season grasses generally fall into two categories: sod formers and bunch grasses. Sod formers spread vegetatively by underground shoots and form a solid mat (Kentucky bluegrass is an example). Sod forming grasses suffer less damage when grazed in wet conditions and will fill in bare spots. Bunch grasses generally establish faster and recover from grazing more quickly, but each plant comes from a separate seed, and stands may become “bunchy” as these thin.
Sod-forming Grasses
Sod-forming grasses produce either rhizomes or stolons, which extends laterally, enabling the grass to develop a firm sod. Primary sod-forming grasses are Kentucky bluegrass, smooth bromegrass, and reed canary grass.
Kentucky Bluegrass
Kentucky bluegrass, shown in figure 5, is more traffic tolerant than most grasses. The grass is very palatable and is considered high quality. It is more drought and flood-tolerant than many grass species. It also is very tolerant of overgrazing. Kentucky bluegrass grows only 18 to 24 inches tall, so the grass is best in pastures and not as a hay species. It establishes easier than smooth bromegrass or reed canarygrass. However, it is the lowest yielding grass species commonly used in pastures. Bluegrass is most productive in May and June and again in September and October. Its primary problem is that it grows slowly during the hot, dry part of mid-summer.
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Figure 5. Kentucky bluegrass. Photo provided by ISU Department of Agronomy |
Reed Canarygrass
Reed canarygrass is an excellent grass that tolerates flooding and drought. Reed canarygrass is extremely winter-hardy. It is the highest yielding grass grown in the Midwest. It grows up to 5 feet tall if not mowed or grazed. It is a sod former, so will fill in vacant areas. Reed canarygrass is slow to establish, often taking a year or more to get a stand. If growing reed canarygrass, be sure to plant low alkaloid varieties. Figure 6 provides the characteristics of reed canarygrass..
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Figure 6. Reed canarygrass. Photo provided by ISU Department of Agronomy |
Smooth Bromegrass
Smooth bromegrass, shown in Figure 7, along with Kentucky bluegrass and quack grass, is the most common species in unimproved pastures in the northern Midwest. It is the most winter-hardy grass species grown in Iowa. It is slow to establish, though not as tricky as reed canarygrass. The major problem with smooth bromegrass is that two-thirds or more of the yield occurs during May and June with little regrowth the rest of the year. It also is slow to recover after mowing or grazing. Smooth bromegrass works well for fields that are harvested for hay in June and grazed the remainder of the growing season.
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| Figure 7. Smooth bromegrass. Photo provided by ISU Department of Agronomy |
Bunch Grasses
Bunch grasses do not produce well-developed rhizomes or stolons, and have a tufted growth habit as opposed to dense sod. Upward growth means these are more susceptible to removal by defoliation and overgrazing. Primary bunch grasses are orchard grass, timothy, tall fescue, Italian (annual) ryegrass, and perennial ryegrass.
Orchardgrass
Orchardgrass is an excellent grass for either pasture or hay. It establishes quickly, is ready to graze early in the spring, and recovers quickly from grazing. It produces more forage in the late summer and early fall than any other cool-season grass. Orchardgrass varieties also vary in maturity. Orchardgrass has moderate winter hardiness and could be severely injured with a harsh winter. Figure 8 provides Orchardgrass characteristics.
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Figure 8. Orchardgrass. Photo provided by ISU Department of Agronomy |
Perennial Ryegrass
Perennial ryegrass is a rapidly establishing, high-quality forage. It will grow in early spring and learly fall. However, it is lower yielding than many other kinds of grass and may die out over winter. Its primary use is in pasture and hay fields where snow cover will keep stands for three to four years. Be sure to buy forage types, not turf types. See figure 9.
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Figure 9. Perennial ryegrass. Photo provided by ISU Department of Agronomy |
Meadow Fescue
Meadow fescue is returning as a dominant forage grass in hay and rotational grazing. It has better winter hardiness and palatability than tall fescue and orchardgrass, and does not have “bad” endophyte concerns. Meadow fescue is not rated quite as high on yield potential compared to tall fescue, and is not as tolerant of continuous grazing as tall fescue and orchardgrass, but is excellent in rotational grazing and grass-alfalfa hay systems.
Tall Fescue
Tall fescue is an easy to establish bunchgrass that is slightly less adapted to flooding and drought extremes than reed canarygrass. It is the most traffic and shade tolerant of any of the grasses. On the negative, tall fescue is very unpalatable. Also, if using, one must be sure to get the fungus-free seed. The internal (endophyte) fungus produces an alkaloid that can be detrimental to pregnant mares. Volunteer tall fescue or any tall fescue growing in ditch banks or grassed waterways is likely fungus-infected. A fungus-free type is the best choice to grow. Figure 10 provides Meadow and Tall fescue characteristics.
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| Figure 10. Tall fescue and Meadow fescue. Photo provided by ISU Department of Agronomy |
Festulolium
Festulolium is a meadow fescue x ryegrass cross. The cross improves winter hardiness compared to perennial ryegrass, and quality/palatability compared to meadow fescue.
Timothy
Timothy, illustrated in Figure 11, is moderately easy to establish and very palatable for horses. It is low yielding and tends to be short-lived, lasting three to five years in most stands. It also heads out most of the summer while all other grasses, except the ryegrasses, head only once in May or June. Timothy has poor drought tolerance. It is best adapted to cooler climates and wetter soils, and should only be grown in northern states. Its seed size is considerably smaller than most grasses and must be seeded separately or mixed with legume seed.
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| Figure 11. Timothy. Photo provided by ISU Department of Agronomy |
Kentucky bluegrass has earned its reputation among horse producers for producing a durable turf and nutritious forage. Bluegrass is most productive in May and June and again in September and October. Its primary problem is that it grows slowly during the hot, dry part of mid-summer. Including a legume such as alfalfa or Birdsfoot trefoil in bluegrass, pasture will improve productivity during the summer months. Kentucky bluegrass is a relatively low-yielding grass, so if the pasture is being used to provide the majority of the nutrition for the grazing season, proper management and 2 to 3 acres of bluegrass pasture per mature horse may be needed. If pasture growth slows dramatically during mid-summer months, be prepared to begin partial or full supplemental feeding until the pasture growth resumes.
Tall growing grasses such as smooth bromegrass, orchardgrass, timothy and meadow fescue make excellent pasture and are more productive than bluegrass. Of the three, orchardgrass maintains a slightly better distribution of growth through the summer months. Reed canarygrass and tall fescue are two more tall kinds of grass used for horse pasture. However, they are considered less palatable than bromegrass, orchardgrass, timothy, or meadow fescue. Reed canarygrass is a good choice on wet sites and where flooding occurs. Reed canarygrass remains more palatable when clipping or grazing maintains the pasture height at about 5 to 6 inches. When considering varieties of Orchardgrass, Tall fescue, Meadow fescue, Ryegrass, and Festuloium, select those rated for good resistance to leaf rust.
Sudangrass and Sudan‑sorghum hybrids are NOT recommended for horse pasture. These plants have caused an increasing number of cases termed "cystitis syndrome" in horses.
Grass hay such as smooth bromegrass, orchardgrass or timothy can be used for mature horses. Grass hay should be fertilized each year with nitrogen to be productive. Apply 60 to 80 lbs/A of nitrogen in early spring and a second 60 lbs/A after the first harvest. Also, apply, annually, 40 lbs/A of P205 and 80 lbs/A of K20 in early spring or after the first harvest. Grass hay yields often range from 3 to 4 tons per acre.
Mixing legumes with grasses often improves productivity, nutritive quality, and distribution of forage production compared with all grass pastures. Alfalfa and red clover are most compatible with smooth bromegrass and reed canarygrass or mixtures of these with orchardgrass or fescue. In a mix, these taller growing legumes and grasses will maintain excellent levels of productivity under a 'close, but not frequent' grazing program and are better suited to a 3 or 4 pasture rotational grazing program. Birdsfoot trefoil and Ladino white clover are most compatible with bluegrass, orchardgrass, and timothy. In a mix, these forages will maintain reasonably good productivity under a 'frequent but not close' grazing program. Or, are better suited to a situation where continuous grazing is used. If this latter situation is what you have, fewer animals on the limited acreage are suggested to prevent overgrazing and loss of the legume component. If pasture growth slows dramatically during mid-summer months, be prepared to begin partial or full supplemental feeding until the pasture growth resumes. Remember, legumes maintain vigor and longevity best if given a 4 to 6 week 'rest' in September and early October each year
Typically, alfalfa and alfalfa-grass mixtures are planted in early spring with a small grain companion crop. Common companion crops used with alfalfa seedings include spring small grains of oats, barley, and triticale. Small grains planted alone can also provide temporary or short-season grazing options of satisfactory feed value. Winter small grains of rye, wheat, and triticale can be planted in early fall for grazing in late autumn and spring. Grazing research from the University of Minnesota showed horses preferred wheat over rye, barley, and oats. Spring planted oats for forage is best for late spring and early summer grazing. Spring oats can also be planted in early August for fall grazing or hay harvest.
After the seeding year, alfalfa and dominant alfalfa meadows should be fertilized annually, preferably immediately after the first harvest, with about 50 lbs/A of P205 and 180 to 200 lbs/A of K20. Higher rates may be necessary if soil tests are in the low or deficient range or where five or more tons of hay are harvested annually.
Expect at least three cuttings from established alfalfa-grass meadows. Yields will range from 3.5 to 5 tons per acre. Make the first harvest at first flower; this usually occurs in late May or early June. The second and third harvests can be taken at 35 to 45-day intervals, again at about the first flower stage of development. Try to time the last summer cut for late August to early September. Cutting at earlier stages of development will produce higher nutritive value hay with finer stems, but often at the sacrifice of total yield harvested and stand longevity. Coarse stemmed, low feed value hay usually results when meadows are cut later at mid‑ to late‑bloom stages of maturity.
Alfalfa and alfalfa‑grass hay meadows should be 'rested' from early September through mid-October each year to provide for the build-up of winter food reserves in the plant roots and crowns. These reserves are necessary for winter survival and vigorous plants for the following year. If growth is adequate after the fall rest period, a fourth hay harvest or grazing may be possible in mid‑ to late October. Be sure to leave a stubble height of at least 5-6 inches to provide some insulation for the overwintering stand.
Red clover with orchardgrass or timothy can also be used for horse hay. However, red clover takes longer than alfalfa to dry down in the field to an appropriate moisture for hay harvest. If baled too wet it could get moldy. Do not feed moldy hay as it can cause colic and irritation to the eyes, nose, or lungs. Clovers are highly pubescent which increases the chance of producing a dustier hay product. They also have a shorter stand life and produce lower yields than alfalfa. An advantage of the clovers is that they will grow on wetter, lower fertility sites than will alfalfa. They are also slightly later in maturity compared to alfalfa and may fit better within other cropping operations on the farm.
Table one provides pasture seeding mixtures. Be sure to select varieties with preferred traits such as non-endophyte, low alkaloid, good winter hardiness ratings, leaf rust resistance, etc. Avoid varieties listed as VNS, which stands for variety not stated. Better seed houses not only provide a good selection of varieties with the most desirable traits but will also offer to custom blend specific varieties for a small additional fee. For example Welter Seed Company in Onslow, IA will custom mix forage varieties for $0.06 per pound. Additional companies are available to mix seeds.
One of the more popular legume‑grass forage mixtures used in Iowa is a combination of alfalfa, smooth bromegrass, and either orchardgrass or fescue (Tall or Meadow) or timothy. This hay mixture is well suited to the Iowa climate and with careful management will remain productive for 4 to 5 years. An additional advantage of this mixture is its uniformity of production during the growing season. Season-long growth provides an option for one or two hay harvests early in the season and grazing later when many grass pastures are less productive. Table 2 includes seeding mixtures for hay and pasture.
Managing Hay and Pasture
Do not overuse or abuse a new meadow (or pasture) in the establishment year. Use management that encourages the development and growth of the forage seedlings. Removing an oat companion crop early as a hay crop or with quick, light grazing will aid the establishment of the forage seedlings. A modest late-summer hay harvest or light grazing is often available in the seeding year. Avoid close or continuous grazing during the seeding year. And, be sure to allow the plants to have a 6 to 8-week 'fall rest' starting from early September on, to gain vigor and to develop winter-hardiness.
Proper grazing management involves keeping both the animals and the pasture plants growing and healthy. It is a three-component system: the plants, the animals, and you. Certainly providing palatable, highly digestible forage for the entire grazing season is ideal for the animal component of grazing management. The pasture plants, whether grasses or legumes remain most productive when they are well fertilized and can maintain several inches of growth throughout the grazing season.
Overgrazing is a severe hazard to pasture production. Horses are inclined to graze plants close to the ground. This kind of grazing will retard the further growth of the pasture plants. If continuous close grazing is practiced, legumes can be lost entirely from the mixture, and the weakened grass sod will allow weeds to establish in the pasture. When pastures become short, it is best to move the animals to another field. It is proper management to have at least two separate pastures for each group of horses you are managing. Three or four pastures per group are better and allow greater flexibility in grazing management. If other pastures are not available, move horses to exercise lots and feed hay for two to three weeks until pastures recover.
Kentucky bluegrass‑based pastures should be allowed to reach about 4 to 5 inches of height before grazing for the first time in the spring, then graze back to 2 to 3 inches. Allow regrowth to reach about 4 inches before grazing again. Among the taller grasses, orchardgrass retains some lower leaves, so like Kentucky bluegrass it can tolerate shorter grazing, although its preferred to not graze it shorter than 3 to 4 inches. The rest of the tall grasses are not very tolerant of close grazing and should be allowed to reach a height of about 8 inches before being grazed down to no more than 4 inches. It follows an old rule of thumb of “take-half, leave-half”. Because most tall grasses store carbohydrate reserves for regrowth in their lower stems, grazing too short adversely affects the rate of regrowth. Grazing too short also causes significant slough-back of roots, reducing nutrient and water uptake. Leaving some lower leaf area helps maximize photosynthetic area for recovery and minimizes open ground exposure to weed encroachment. Figure 12 illustrates the effect of removing the top growth of plants on the root structure and growth of the plant.
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| Figure 12. Regrowth as affected by top growth removal. From the New Zealand Sheep Council, September 2000 |
The percent leaf volume removed and percent root growth stoppage in pasture plants is listed in Table 1.
Table 1. Percent leaf volume removed and percent root growth stoppage in pasture plants
| % leaf volume removed | % root growth stoppage |
| 10-40% | 0% |
| 50% | 2-4% |
| 60% | 50% |
| 70% | 78% |
| >80% | 100% |
| From the New Zealand Sheep Council, September 2000 |
Pasture quality can be improved during the season by clipping to remove uneaten clumps, unpalatable growth, and weeds. Scattering the droppings also encourages more uniform grazing.
Fertilize grass pastures according to soil tests. Generally, if grass pastures are medium or higher in phosphorus and potassium, no additional P or K are needed. If the soil tests are low or very low, apply 30 to 40 lbs/A each or P205 and K20 annually and retest in three years. For legume‑grass pastures annually apply P205 and K20 P when soil test levels are in the medium or lower category. Grass-based pastures are much more productive when fertilized with nitrogen. The greatest efficiency of nitrogen use comes when a portion is applied in early spring and a part in late-spring and/or in late-summer. Fertilize Kentucky bluegrass‑based pastures with 40 to 80 lbs/A of nitrogen in the spring and an optional 30 to 50 lbs/A in late-spring and/or in late-summer. Taller grasses such as smooth bromegrass and orchardgrass will respond well to 60 to 100 lbs/A of nitrogen in the spring and an additional 40 to 60 lbs/A in late-spring and/or in late- summer. If a mixed grass-legume pasture is less than 1/3 legume, treat as a grass pasture and apply nitrogen for increased productivity. Legume dominant fields generally need no additional nitrogen. For more details, see ISU Extension Pamphlet 869, Fertilizing Pastures.
Weeds can become troublesome in pastures. Clipping several times a year and hand digging may be sufficient. However, if low‑growing broadleaf weeds become a problem, a herbicide application may be required. Where herbicides are necessary for weed control, expect to see a decline or loss in legume plants. Applying 1 pound of active ingredient 2,4‑D per acre in the spring when weeds are 3 to 4 inches tall will often be effective in controlling annual broadleaf weeds. The second application in mid-autumn (mid-September through mid-October) may be necessary where dandelions and biennial thistles are a problem. Repeat these twice-annual applications until weeds are under control. After that, only occasional spraying or clipping may be all that is necessary for continued control. Perennial weeds and brush offer more significant challenges. Consult an ISU Extension Agronomist, or trusted Agri-chemical dealer for recommendations of appropriate herbicides and timing. Remember to read and follow label instructions for any pesticide or ag chemical used.