Characteristics of a bunch spear grass (Heteropogon contortus (L). BEAUV.) pasture grazed by cattle in subtropical Queensland.

Abstract

A study of a native pasture of bunch spear grass (HHeteropogon contortus (L.) Beauv.) grazed by beef cattle in subtropical Queensland is reported. The yield and botanical and chemical composition under continuous grazing were recorded over 4 years. Spear grass contributed up to 90 per cent. of the yield of dry matter which ranged from 1 to 2 tons/acre. Approximately 60 per cent. of the total yield was produced between January and April, and there was almost complete absence of growth in the cooler months even when rain occurred. The nutritive value of the forage was low for much of the year, with the crude protein content falling to 2-3 per cent. in the winter. The degree of consumption of forage by stock was low, particularly in the winter, and it was apparent that under the existing form of management the stock had little effect on the pasture. It is concluded that there is little prospect of increasing beef production per acre by grazing management of the native pasture, and that, as the major drawbacks to production stein from the pasture species rather than the climate in which they grow, the logical approach is to replace them by sown grasses and legumes. This involves studies of introduced species and, as many of the soils are of low fertility, attention to plant nutrient deficiencies. Work along these lines is now in progress.

The use of sampling methods in studies of the distribution of larvae of Boophilus microplus on pastures.

“…The observation that the creek flats were grazed more heavily in the dry than in the wet season, is complementary to the deductions of Shaw and Bisset (1955) that the reverse tendency occurs in intensity of grazing hillsides. The cattle-hours index of area 2 of the 400-acre paddock was probably not representative of the grazing intensity of ridges because of the use of the area for resting at night and because of the destruction of the grass by fire.…”

Fire and The Australian Flora: A Review

“…isohyets (Isbell 1969). It is often associated with Themeda australis, Bothriochloa, Aristida, Eragrostis, Chloris and Chrysopogon (Shaw and Bissett 1955) in grassy forests and woodlands (Tothill 1969). Annual burning during the dry season favours dominance of H eteropogon (Shaw 1957) and light grazing may enhance this at least where Themeda is an associate (Isbell 1969).…”

Methane Emissions and the Use of Desmanthus in Beef Cattle Production in Northern Australia

“…The prevailing pasture species are mainly C4 grasses, which have lower nutritional value than temperate grasses, and result in lower animal productivity than in temperate regions [28,29]. During the wet, hot summers, these pastures grow quickly and persist through the dry winter seasons as mature grasses [30,31,32]. The low livestock productivity in northern Australia is especially due to low protein content and low digestibility during the dry season [33].…”

“…The low livestock productivity in northern Australia is especially due to low protein content and low digestibility during the dry season [33]. The low digestibility (45% organic matter) and nitrogen content (less than 7g N/kg dry matter (DM)) of these grasses during the dry season results in poor forage intakes and low annual growth rate of young cattle [30,31,32]. Animals tend to put on weight in the wet season and lose weight in the dry season.…”