V.R. SQUIRES

Department of Natural Resources, Roseworthy Agricultural College, Roseworthy, South Australia 5371

Abstract

Australia has large expanses of tropical rangelands, both arid and seasonally arid (Monsoonal). Merino sheep and beef cattle are run under extensive free-ranging conditions. The management strategies, although not identical for the arid and the monsoon tropics, depend on a knowledge of livestock behaviour.
Aspects of foraging behaviour such as grazing distribution and diet selectivity are discussed. The concepts of species selective grazing, area selective grazing, search image, and energy optimisation are evaluated in relation to free-ranging cattle in inland Australia.
Cattle appear to optimise energy consumption by moving to a fresh grazing area when the level of utilisation on key forage species was between 51–75% and to exercise their own rotation under free-range conditions. Management implications of grazing behaviour, paddock size, and distribution of watering points are discussed in relation to rotational grazing systems, mating efficiency and grazing impacts.