Heavy steers and heifers run at low stocking rates enhance drought resilience in a pastoral region of Australia

Abstract

CONTEXTThe semi-arid mulga lands of the Southern Rangelands of Western Australia experience frequent droughts. Maintaining a profitable animal grazing enterprise whilst preserving rangeland condition requires selecting an appropriate stocking rate and herd structure. OBJECTIVEWe construct and apply bioeconomic models of beef enterprises for the semi-arid Southern Rangelands of Western Australia, to assess the profitability and relative riskiness of three different livestock production systems and three different stocking rates when exposed to different frequencies of drought. METHODSWe construct bio-economic models of herd structures that separately focus on producing either: (i) 200 kg heifers and 210 kg steers (ii) live export of 340 kg heifers and 380 kg steers, or (iii) 500 kg heifers and 560 kg steers for local slaughter. The models are applied to assess the financial and production resilience of each herd structure for three different stocking rates, given the incidence of drought and various price scenarios. RESULTS AND CONCLUSIONSComparing the three herd structures, option (iii) produces more kilograms of beef at an equivalent grazing pressure and recovers fastest from drought. Considering cattle prices over the 7-year period ending in 2021, live export and slaughter production systems generate comparable financial returns to graziers' actual reported results. Under two different scenarios of future prices, option (iii) provides the most profitable outcome. Applying a stocking rate that is 66% of a recommended stocking rate allows use of residual rangeland feed (known as ‘haystack’) during drought, generates greater profit, and produces a more stable herd size and income. Not matching the haystack with the longest modelled drought reduces the grazier's average annual profit by $172,000. The optimum herd structure identified in this study targets the production of 500 kg heifers and 560 kgs steers for local slaughter, and relies on a conservative stocking rate that leaves enough haystack to increase resilience if ever consecutive droughts occur. SIGNIFICANCEIn the Southern Rangelands of Western Australia, there are financial and environmental merits in a herd structure that produces heavy steers and heifers for local slaughter yet is underpinned by conservative stocking rates.