The effect of plant structure on the acceptability of different grass species to cattle

Abstract

The changes in the acceptability to cattle of nine indigenous grass species over the grazing season were related to nine characteristics of the species. Acceptability was positively related to tuft diameter, leaf percentage, leaf table height and leaf crude protein, but was negatively related to stemminess. Species of preferred acceptability were leafy and non‐stemmy, with a high leaf table and had leaves of low tensile strength containing high crude protein. Avoided species were generally stemmy and had leaves containing low crude protein. Acceptability was largely determined by plant structure but was also influenced by leaf crude protein and tensile strength. Plant structure appears to modify acceptability by altering the nutritive value of the plant to the animal through its effect on intake rates. It is suggested that stemminess may increase resistance to herbivory by limiting the degree of tissue loss.