Grass mixtures for Midwest horse pastures

Cool-season grasses are the basis of productive horse pastures in the Midwest. As selective grazers, horses can graze forage species shorter than other livestock. This grazing behavior can:

• Limit the growth and survival of some forage species

• Affect uniform use, yield and persistence of forage species, especially if horses repeatedly graze preferred species

We looked at horse preference, yield and species persistence of cool-season grass mixtures under horse grazing. Understanding these characteristics in grass pasture mixes can help you select an ideal grass pasture mix.

Testing grass mixtures

We grazed four adult horses on eight commercially marketed cool-season pasture mixes. All mixtures contained four to six cool-season perennial grass species (table 1).

We measured the species population density each spring and fall and the yield before each grazing. We took and dried subsamples of forage to determine dry matter content for yield.

Post grazing we visually assessed horse preference by the percent of forage removed on a scale of 0 (no grazing) to 100 (100 percent of vegetation removed).

Results

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Horse preference

Horses preferred mixtures containing the following species (table 1):

• Endophyte-free tall fescue

• Perennial ryegrass

• Kentucky bluegrass

• Timothy

Horses had less preference for mixtures containing 30 percent or more orchardgrass. A more preferred mixture will result in more uniform grazing, which increases forage use and reduces maintenance (e.g. mowing).

Yield

Mixtures had similar forage yields that ranged from 2.7 to 3.2 tons per acre (table 1). After two years of grazing, populations of:

• Orchardgrass and endophyte-free tall fescue increased from initial percentage of the mixtures

• Kentucky bluegrass remained constant

• Meadow fescue and perennial ryegrass had the greatest rate of decline (figure 1)

• Orchardgrass became the dominant species, regardless of initial percentage in the mixture.

Recommendations

You should plant the following species in Midwest horse pastures.

• Endophyte-free tall fescue

• Perennial ryegrass

• Kentucky bluegrass

• Timothy

Over time, endophyte-free tall fescue and Kentucky bluegrass will likely dominate these mixtures.

Planting mixtures similar to Agassiz CHS #4 and La Crosse BLM #4 should result in high yielding, persistent and preferred grass horse pastures in the Midwest (table 1).

Table 1. Initial composition, forage yield (ton per acre) and preference (percent removal) of eight cool-season grass mixtures grazed by horses in Minnesota.

Mixture	Species	Initial mixture composition (%)	Yield (tons/acre)	Preference (% removal)
Agassiz CHS #4	Tall Fescue	40	3.1	88
	Perennial Ryegrass	30	3.1	88
	KY Bluegrass	15	3.1	88
	Timothy	15	3.1	88
Agassiz MN-G	Meadow Bromegrass	30	3.2	45
	Orchardgrass	30	3.2	45
	Tall Fescue	30	3.2	45
	Perennial Ryegrass	10	3.2	45
CR Heavy	KY Bluegrass	45	2.7	46
	Orchardgrass	35	2.7	46
	Timothy	20	2.7	46
	Perennial Ryegrass	10	2.7	46
CR Light	KY Bluegrass	40	3.1	48
	Orchardgrass	20	3.1	48
	Crested Wheatgrass	10	3.1	48
	Meadow Bromegrass	10	3.1	48
	Perennial Ryegrass	10	3.1	48
	Timothy	10	3.1	48
Dan Patch	KY Bluegrass	40	3	59
	Smooth Bromegrass	20	3	59
	Perennial Ryegrass	15	3	59
	Orchardgrass	15	3	59
	Timothy	10	3	59
La Crosse BLM #4	Perennial Ryegrass	30	2.8	91
	Annual Ryegrass	20	2.8	91
	Tall Fescue	20	2.8	91
	KY Bluegrass	15	2.8	91
	Timothy	15	2.8	91
Marties	Timothy	40	2.7	67
	Tall Fescue	25	2.7	67
	Orchardgrass	20	2.7	67
	KY Bluegrass	10	2.7	67
	Perennial Ryegrass	5	2.7	67
Waconia Mix	KY Bluegrass	35	3.1	63

Authors: Krishona Martinson, Extension equine specialist, Craig Sheaffer, professor of agronomy and plant genetics, College of Food Agriculture and Natural Resource Science, and M. Samantha Wells, Extension agronomist