Despite the high potential of tropical forage species, herbage production, nutritive value and animal produc-tion in Brazilian livestock production systems are lower than what should be obtained from both a biological and operational point of view (Pedreira and Mello 2000). Even with these limitations, the livestock industry is often able to sustain high levels of productivity (animal product per hectare) by using good animal genetics and supplementation. Reducing production costs, however, will likely depend on the identification and incorporation of a high-quality forage resource, in terms of both im-proving diet quality of grazing animals and sustaining pasture soil productivity.