Quick facts
- Grass and legume forage mixtures provide benefits for horses with higher nutrient needs.
- Alfalfa can be grazed as a single-species or mixed with grass.
- Mixed pastures may not be appropriate for horses that are overweight or prone to certain metabolic conditions.
- Legumes can be safely grazed by healthy horses.
The importance of pasture to horses
Horses are grazing animals and most horses in the Midwest meet their nutritional needs from cool-season grass pasture or hay.
Forages are an important part of the equine diet and more than 80% of horses have some pasture access. There are many benefits for horses grazing pasture compared to eating hay in confinement, including the reduction of unwanted behaviors such as bedding and manure eating, cribbing and chewing wood.
Benefits of adding legumes to pasture
Grass pasture alone often does not meet the greater energy and nutrient needs of growing horses, horses in heavy work, and lactating mares. But they may not be appropriate for horses that are overweight or prone to certain metabolic conditions.
Legumes such as alfalfa and white clover can meet elevated needs and can be planted with grasses to improve the nutritional value of forages.
Alfalfa and clover contain more digestible energy (DE) and crude protein (CP) than grasses. They are a good option for owners who want to limit feeding grain to their horses.
Grass-legume pastures offer added benefits, including:
- Increased crop yield.
- Better weed control.
- Improved seasonal distribution of forage.
- Greater adaptability to weather conditions.
- Legumes can fix nitrogen and transfer it to grasses, reducing nitrogen fertilization needs.
Although common in horse hay, legumes are rarely grazed as the sole forage species.
- Alfalfa can be grazed as a single-species or mixed with grass.
- Red or white clover doesn't regrow well when grazed by horses, so it’s best to mix with grass.
- Alfalfa and red clover can be appropriate pasture species for horses diagnosed with metabolic disorders. If your horse has a diagnosed metabolic disorder, work closely with your veterinarian and an equine nutritionist before grazing.
Horses readily eat legumes mixed with grass. In a three-year study of feeding alfalfa and clover though, horses showed a preference for red and white clover.
Weed control
Weeds pose a problem in pastures, as they can reduce yield and forage nutritive value. Certain weeds can pose a toxicity risk to grazing livestock. Grass-legume mixtures tend to create a more competitive environment compared to grasses planted by themselves. Mixtures can be an effective management tool to help reduce weeds.
- Herbicides for weed control cannot be used in grass-legume mixtures, as products will also injure or kill the desired grasses and legumes, depending on the target weed species.
- Mechanical weed control, including overseeding and mowing in mixed pastures, also works.
Research summaries
Objectives and method
The objectives of this research were to evaluate yield, plant composition, forage nutritive value, and preference of grass-legume pastures under horse grazing.
- Grass-legume mixtures provide benefits for horses with higher nutrient needs.
- Legumes can complement grasses by increasing pasture yield.
- Grass-legume mixtures help control weeds.
- Grass-legume mixtures improve forage nutritive values.
- Legumes can be safely grazed by healthy horses.
How the research was completed
- Small pastures consisting of orchardgrass, Kentucky bluegrass, and meadow fescue were planted alone and in mixtures with alfalfa or white clover and grazed by four adult horses for three years.
- Horses grazed the pastures monthly during the growing season.
- Prior to each grazing, a portion of each pasture was harvested to determine yield and sampled for forage nutritive value and plant composition.
- After each grazing, horse preference was determined by visually assessing plant removal on a scale of 0 (no grazing activity) to 100 (100% of the vegetation grazed).
Yield
- In general, alfalfa tended to complement grasses by increasing yield compared to grasses planted by themselves.
- For example, Kentucky bluegrass-alfalfa mixture had a seasonal yield of 5.8 tons per acre compared to 3.7 tons per acre when Kentucky bluegrass was planted alone.
Forage nutritive value
- In general, forage nutritive values improved when legumes were planted with grasses, including higher crude protein and lower fiber values.
- For example, during the third year of grazing, the Kentucky bluegrass-alfalfa mixture had 20% crude protein and 48% neutral detergent fiber compared to 16% crude protein and 55% neutral detergent fiber when Kentucky bluegrass was planted alone.
Horse preference
All of the forages were readily grazed by the horses, who consumed most of the forage in each pasture.
Minimal differences in horse preference were observed when horses grazed the pastures.
Researchers:
Krishona Martinson, Scotty Wells, and Craig Sheaffer, University of Minnesota; Michelle DeBoer, University of Wisconsin-River Falls; and Amanda Grev, University of Maryland
Objectives
We looked at the possibility of grazing horses on legume pastures. And we found that legumes are a good option for those looking to increase the forage nutritive value of their pastures.
- Alfalfa can be grazed as a single-species or mixed with grass.
- We recommend mixing red or white clover with grass because clover doesn't regrow as well when grazed by horses.
- Legumes can be safely grazed by healthy horses.
- Alfalfa and red clover can be appropriate pasture species for horses diagnosed with metabolic disorders. If your horse has a diagnosed metabolic disorder, work closely with your veterinarian and an equine nutritionist before grazing.
Method
- Six adult, stock-type horses grazed on legume and legume-grass pastures in rotation.
- We tested eight alfalfa varieties, one red clover variety and one white clover variety.
- We looked at yield, nutritional quality and horse preference of the different forages.
- We completed the study over multiple years and seasons.
Forage yield and persistence of regrowth
- Alfalfa and alfalfa-grass pastures had the greatest yields, meaning there was more forage available for the horses to eat compared to clover or clover-grass pastures.
- There was no difference in yield between alfalfa and alfalfa-grass pastures.
- Adding grass to a clover pasture did increase the yield.
The horses grazed the pastures in rotation. But, by the start of the third year, the pastures had damage that was likely from a combination of hoof traffic, grazing pressure and winter weather events such as ice sheeting.
Both clovers had greater damage (bare ground) compared to the alfalfa. When grass was added to the clover, the pastures had better ground cover compared to clover planted without grass.
Forage nutrient content
All legume and legume-grass pastures provide a high level of nutrition and exceed the needs of an adult, idle horse.
Equine digestible energy (DE) was high across all legume and legume-grass pastures. For adult idle horses or those with unlimited access to grazing, this may result in excess weight gain. However, for horses needing to gain weight, those in work, and other horses with higher caloric needs, legumes provide an advantage over grass-only pastures and may help alleviate a need for feeding grain.
With the exception of white clover, all legumes and legume-grass pastures were below 12 percent nonstructural carbohydrates (NSC). Alfalfa pastures contained 10 percent NSC on average.
NSC at or below 12 percent meets the amount of NSC recommended for horses diagnosed with obesity, laminitis, equine metabolic syndrome, or Cushings, which means that these horses can potentially graze alfalfa or red clover pastures. Owners should still routinely test the pasture and establish a grazing plan with help from a veterinarian or equine nutritionist.
Animal preference
Horses displayed the strongest preference for red and white clover species. But they highly preferred and readily consumed all legumes.
Researchers:
Devan Catalano, graduate student, College of Food, Agricultural and Natural Resource Sciences; Krishona Martinson, Extension equine specialist; and Craig Sheaffer, professor of agronomy and plant genetics, College of Food, Agricultural and Natural Resource Sciences
Catalano, D.N., C.C. Sheaffer, A.M. Grev, M.L. DeBoer and K.L. Martinson. 2019. Yield, Forage Nutritive Value, and Preference of Legumes under Horse Grazing. Agronomy J. 111: 1,312-1,322. https://doi.org/10.2134/agronj2018.07.0442
DeBoer, M.L., Grev, A.M., Sheaffer, C.C., Wells, M.S., Martinson, K.L. Herbage mass, botanical composition, forage nutritive value, and preference of grass‐legume pastures under horse grazing. Crop, Forage & Turfgrass Mgmt. 2020. 6:e20032. https://doi.org/10.1002/cft2.20032
Reviewed in 2024