It is equal to bluegrass, and outside the bluegrass area it should be first choice for horse pastures. Orchardgrass withstands closer grazing than timothy and is not as aggressive to a companion legume as fescue, bromegrass or Reed canarygrass. However, it is not the best forage for horses because it lacks acceptability. Horses sometimes do poorly on it unless their ration is fortified with grain. This is especially true of mares with suckling colts.
Most tall fescue is infected with an endophyte fungus.
Mares grazing it during late gestation may fail to develop a normal udder and may have no colostrum at foaling time. Other problems associated with tall fescue include stillborn foals, thick, tough placentae and longer than normal gestation length. Several new varieties of tall fescue have been developed that are free of this endophyte fungus, but if the fescue pasture used for mares contains the fungus, mares should be removed from it at least 60 days prior to foaling. A fescue-legume mixture is more desirable for horse pastures than fescue alone. Some fescue can be used for late fall and winter grazing.