Does it matter how much grass your cattle eat?

How much of your annual pasture growth can be grazed without causing a decline in land condition? For rangeland managers, knowing the safe pasture utilisation rate is the key to maintaining or improving land condition and buffering the effects of climate variability in Central Australia.

Quality Graze is a long-term grazing trial that has been running on the Old Man Plains Research Station near Alice Springs since 2010. Getting the long-term stocking rates right has allowed for significant land condition improvement while grazing a productive premium beef cattle herd Quality Graze – so much more than a rotational grazing project! – FutureBeef.

In 2023, researchers made an exciting breakthrough in their understanding of the effects of grazing on native pastures. Using pasture growth models in conjunction with actual field data, they have been able to determine how much pasture has grown in each year of the project and, because they have accurate stock records, they have also been able to calculate the amount of annual growth that was eaten every year. This has allowed calculation of the pasture utilisation rate over a range of seasons and therefore the average, or ‘safe’ utilisation rate, for maintaining good land condition. Utilisation rate is a significant piece of the puzzle when working out long-term carrying capacity, so it is exciting to have this data available for land types in Central Australia.

The 14-year Quality Graze project has experienced very dry periods and the wettest years on record, which builds confidence that the data are representative of our variable climate. The average utilisation rate on the research station was 15% across several land types over the 14 years. The research will be used to update recommended utilisation rates for estimating carrying capacity. “This is the first time we’ve had a grazing trial in the Alice region that can inform safe utilisation rates for the local conditions and pastures,” says Dr Robyn Cowley, Senior Rangeland Scientist.

For more information on utilisation rates and carrying capacity, please contact Chris Materne on (08) 8951 8135 or chris.materne@nt.gov.au.