Seasonal variation in in vitro digestibility and chemical composition of a range of alpine plants, from Victoria, Australia.

Abstract

Seasonal trends in in vitro digestibility, nitrogen, calcium, magnesium, phosphorus, potassium and sodium content were assessed for 10 alpine plant species, during the summer months of 1981182, on an alpine range in north-east Victoria, Australia. In March, 1983, at the end of an unusually dry summer the same species were tested for in vitro digestibility and nitrogen content. In vitro digestibility and nitrogen content of the alpine plant species sampled were estimated to be sufficient for lactating pregnant cattle during December and January. Towards the end of the grazing season, from late February until late March, the in vitro digestibility and nitrogen content of some of the common alpine species had declined to a point where they were too low to provide cattle with sufficient energy and protein. In general, the level of the macro-element content of the plants, as sampled, was inadequate for optimum animal production throughout the season.