Grazing pressure, land condition, productivity and profitability of beef cattle grazing buffel grass pastures in the subtropics of Australia: a modelling approach

There is widespread evidence that beef cattle land managers in Queensland are using stocking rates for perennial pastures that are substantially higher than recommended guidelines, and some indication that these decisions are motivated by perceived financial and economic benefits. Considerable effort has been, and is currently being, applied by public-sector organisations to encourage producers to reduce grazing pressure from beef cattle across Queensland’s pastoral lands. A better understanding of the relationships among stocking rate, land condition and profitability of beef-grazing enterprises is imperative to better inform cattle producers and policy makers. The present study assessed the effect of grazing pressure and land condition on the productivity and profitability of a steer-turnover enterprise utilising buffel grass (Cenchrus ciliaris) pastures in central Queensland. A property-level, regionally relevant herd model was used to determine whole-of-business productivity and profitability over a 30-year investment period. Growth paths for steers from weaning to marketing were developed for 16 scenarios encompassing a range of pasture-utilisation rates (30%, 35% and 50% of annual biomass growth), land condition (A, B and C) and market targets (feedlot entry at 474 kg or slaughter at 605 kg). The economic effect of each scenario was assessed by comparison to a base scenario of 30% pasture utilisation and turn-off of slaughter steers. Our analyses demonstrated a large economic advantage from increasing grazing pressure above 30% utilisation for buffel grass pastures, even with assumptions of declining land condition and animal performance. For instance, producing slaughter steers under a 50% pasture-utilisation regime with a continuous decline in land condition from A to C (and, hence, productivity) over Years 10–30 was AU$21 772/annum more profitable than was a 30% pasture-utilisation strategy, which is widely recommended as closer to a long-term, safe utilisation rate. The present research has provided insights into the relationship between grazing pressure and economic returns of beef producers over the medium term. However, it should be considered as a scoping study due to the paucity of data for effects of utilisation rate on the productivity of buffel grass pastures and, hence, on land-condition rating. Further research is required to better understand the effects of utilisation rate of buffel grass, and other sown pasture grass and legume species, on plant biomass production, plant-diet quality for cattle, land-condition decline and cattle productivity