Grazing winter and spring wheat crops improves the profitability of prime lamb production in mixed-farm systems of Western Australia

[Truncated abstract] Lamb production in Western Australia has historically been constrained by both within and between season fluctuations in pasture productivity and its frequently low availability and poor nutritive value during the autumn-early winter. Hence, there is a need to investigate alternative feed components that could potentially mitigate feed gaps and increase farm profitability. Grazing immature cereal crops, particularly different varieties of wheat, has become widely used in the high-rainfall areas of southern Australia. Recently, there has been growing interest in applying this technology in drier parts of the mixed-farming zones of Western Australia. A modelling study was conducted to examine farm business returns with or without the grazing of immature wheat (winter and spring varieties) in different locations of Western Australia. Results from a combination of the GrassGro (pasture and livestock simulation model) and APSIM (crop simulation model) were used to evaluate the changes in farm gross margins with the grazing of cereal crops at three locations of Western Australia (Kojonup, Wickepin and Merredin), representing the high, medium and low rainfalls respectively. In this simulation modelling, the lamb production system was based on a Merino ewe enterprise producing crossbred lambs (Poll Dorset × Merino), which were then sold as finished lambs at 45 kg live weight...