Tall Fescue Forage Quality and Agronomic Performance as Affected by the Endophyte

Tall fescue has many desirable agronomic characteristics but animal performance has not always been satisfactory. Reports of poor animal performance associated with the presence of the fungal endophyte Acremonium coenophialum in the plant have prompted many animal‐forage investigations, but few studies have investigated the effect of the endophyte on the plant. Agronomic charcteristics—forage yield, stand persistence, and seed yield—of tall fescue in the U.S. midsouth apparently are not altered by the presence of the endophyte. Forage quality parameters—crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), and in vitro dry matter disappearance (IVDMD)—are not changed by the presence of the endophyte. Two groups of alkaloids, the pyrrolizidine and the ergot alkaloids, are present in plants infected with the endophyte, but the toxins responsible for poor animal performance have not been isolated or identified. Desirable properties of endophyte‐infected grasses include tolerance to insect attack and to overgrazing by herbivores. These characteristics may be required for continued persistence of the grass, whether used as forage or as turf.