Pastures: Cool-Season Grasses
Cool-season grasses begin growth in mid-March (southeastern Pennsylvania) to mid-April (northern tier counties). They produce considerable forage in the spring season. In summer, production is depressed by high temperatures and moisture stress. If moisture supply is normal, production will increase slightly in September and early October and will cease by mid-October or mid-November. Most forage grasses produce highest yields on deep, well-drained (not excessively drained) soils. Some species, such as reed canarygrass, are capable of producing moderate to high yields on soils with very poor drainage, while other species do not persist in these soils.
Spring grazing of grasses can be started earlier by applying 50 pounds of nitrogen in March to hasten the spring green-up.
Cows soon to freshen or with calves at side that are grazing grass pastures in early spring should have access to a magnesium-containing mineral supplement to help prevent grass tetany.
Bluegrass is palatable for grazing and of high quality. It is particularly suited for horse pastures. The grass can tolerate close, continuous grazing but produces low yields under this management. It forms tough sods and resists trampling damage. Because of its low productive capacity, bluegrass does not respond well to fertilizer above low rates. The short growth makes harvesting for hay difficult.
Orchardgrass tolerates continuous grazing if the plant is not grazed below 3 to 4 inches. Production and persistence are better under rotational grazing to give the plant three weeks or more between summer grazings for recovery growth. Begin grazing when the plant reaches 4 inches in the spring, and graze the earliest maturing varieties first. The tall growth and good yield potential make moderate fertilization rates feasible; surplus pasture can be harvested for winter hay or silage.
Reed canarygrass can tolerate continuous grazing, but yields are higher under a rotational system that gives three weeks or more of recovery between summer grazings. The growth potential of reed canarygrass pastures justifies moderate fertilizer rates. Harvesting pastures for hay or silage is feasible. New low-alkaloid varieties are more palatable for grazing animals.
The pasture quality and palatability of smooth bromegrass are good, and it is readily accepted by cattle, sheep, and horses. Bromegrasses tolerate moderate continuous grazing but produce more pasturage under a rotational scheme that allows three or more weeks of recovery. Moderate fertility rates are recommended for bromegrass, and excellent hay or silage can be produced from pastures in surplus growth periods.
Forage quality of timothy pasture is high; beef cattle, sheep, and horses eat it readily. Rotational grazing (3 weeks or more of recovery) favors timothy production and persistence, but the plant tolerates moderate continuous grazing. Grazing can be started in spring at 3 to 4 inches of spring growth, but grazing when the flower stems are elongating can cause reductions in the stand. Moderate levels of fertilization are recommended. The tall growth of timothy allows mowing surplus pasture for hay and silage.
Fescue is quite tolerant of continuous grazing but produces higher yields under rotational grazing. It forms a tough sod, and established pastures hold up well under intense grazing. Grazing may begin in spring at 3 inches of new growth. Surplus pasture growth may be harvested for hay or silage.
Tall fescue is particularly well suited to “fall stockpiling” for early winter grazing. In this practice, animals are removed from fescue pastures from August 1 to August 10, and 70 to 80 pounds of nitrogen per acre are applied. The resulting growth can be grazed in November to January, as snow cover permits. Stockpiled growth is of high quality through December.
Many quality problems of tall fescue are associated with the presence of an endophytic fungus growing in the plants. New varieties of tall fescue that contain no endophyte fungus are available and should be used when establishing new or renovating old pastures. Exclusive grazing of old fescue varieties during the summer occasionally leads to a condition known as “fescue syndrome,” in which cattle retain their winter coat, breathe rapidly, and gain poorly. Using low-endophyte tall fescue varieties eliminates this risk.
Annual ryegrass is a cool-season bunch grass native to Europe. It is highly adaptable to a wide range of soil types and can tolerate abuse by both livestock and the producer. It establishes relatively quickly and produces a very palatable and digestible forage. Annual ryegrass in Pennsylvania is planted most frequently in late summer, provides fall grazing, goes dormant over the winter, resumes growth in the spring, and then dies as the temperature and moisture stress increase in early summer.
Pastures of perennial ryegrass are high in quality and animal acceptability. Cattle, sheep, and horses all perform well on the forage. It is an excellent species for use in creep grazing pastures for young animals. The grass may be grazed continuously, but greater pasture yields result from rotational grazing systems that allow for three weeks or more of regrowth. Pastures may be grazed when spring growth reaches 3 inches in height. Hay yields may be low unless considerable time for accumulation is allowed. Grow this species in mixtures with legumes (alfalfa, red clover, white clover); it may help prevent bloat if grazed with or instead of legumes.