Agronomic potential of native grass species on the Northern Tablelands of New South Wales. II. Nutritive value

Abstract

The quality of three year-long green and three summer-growing, frost-susceptible perennial native grasses was compared with that of two introduced temperate perennial grasses and white clover (Trifolium repens L. cv. Haifa). Digestibility of white clover generally exceeded that of all grasses, except for the green leaves of the two introduced species, Festuca arundinacea Screb. cv. Demeter and Phalaris aquatica L. cv. Sirosa, during winter. The digestibility of the green leaves of most winter-green species increased during winter and decreased in summer, the extent of this being greater for the introduced grasses.The digestibility of fescue and phalaris was generally similar throughout the study and was mostly higher than that of the native grasses, but the quality of the green leaves of two year-long green native species, Danthonra linkii Kunth and Microlaena stipoides (Labill.) R.Br., approached that of the two introduced grasses. The quality of the summer perennial species was poor during winter owing to the presence of only dead leaves, but the green leaves of Bothriochloa macra (Steud) S. T. Blake retained high levels of digestibility during summer. Considerable variation in digestibility exists between individual plants of Poaseiberana Spreng, indicating that opportunities may exist for selection of highly productive lines from some native species.In pen-feeding studies, voluntary intake of most of the year-long green native grasses was similar to that of the introduced grasses, but intake of the summer perennial species tended to be lower.Results from this study indicate that the quality of native pastures and their potential for animal production will vary considerably according to species composition, season and the presence of white clover.