ABSTRACT
s. Fescue toxicity or "fescue foot", poor animal performance or "summer syndrome", and fat necrosis are some physiological disorders observed in cattle grazing tall fescue, Festuca arundinacea Schreb. Alkaloids in the plant, mycotoxins, and other secondary metabolites from systemic fungi, and organic acids have been implicated. Comparisons of cultivars and genetic studies of alkaloid types and concentration levels have been reported for Festuca, Lolium, and Phalaris. The tryptamine alkaloids in Phalaris species have been implicated as the cause of "phalaris staggers" and may also be associated with bovine emphysema. Heritability estimates for total indole alkaloids in reed canarygrass indicated high additive genetic variance. Alkaloids in tall fescue and reed canarygrass have been shown to contribute to nonthrifty appearance of animals grazing these forage grasses. The low liveweight gains by animals consuming these grasses at times when alkaloid concentrations are high document the biological and agricultural significance of alkaloids.
