Comparison and Diet Preference of Novel Endophyte-Infected Tall Fescue Cultivars

A fungal endophyte, Epichloe coenophiala (Morgan-Jones & W. Gams) C.W. Bacon & Schardl, naturally infects tall fescue [Lolium arundinaceum (Schreb.) Darbysh.]. The common, toxic endophyte produces ergot alkaloids that cause the livestock disorder known as tall fescue toxicosis. Strains of E. coenophiala that produce little or no toxic ergot alkaloids are referred to as “novel” endophyte associations and offer a solution to tall fescue toxicosis. The objective of this study was to determine differences in animal preference and ground cover among commercially available novel endophyte-infected tall fescue cultivars. Six cultivars of novel tall fescue and controls of common, toxic endophyte-infected and endophyte-free tall fescue were evaluated for animal preference, forage mass, forage removal, forage quality, and ground cover during a 2-yr grazing trial at Linneus, MO. Plots were grazed over nine grazing events by beef cattle (Bos spp.) during the 2-yr study, and some animals were fitted with GPS collars to determine which cultivar was grazed first and most often. ‘BarOptima’, a soft-leaf cultivar, was grazed first and most frequently. Forage mass, forage removal, and forage quality measurements of crude protein, acid detergent fiber, and neutral detergent fiber were similar among cultivars. Ground cover increased each year of the study, even though seed production was inhibited. In addition, rust (Puccinia spp.) susceptibility differed among cultivars. Under this management system, which used up to 24-h grazing periods and at least 8-cm stubble height, animal preference was not based on endophyte status.