Investigating grazing management systems in northern Australia Volume 1

Abstract

Beef producers face increasing environmental and financial pressures to remain productive and viable. Many are considering using more intensive grazing systems to achieve their goals but are unsure of the costs and benefits of alternative systems. This research project was developed to provide information on different intensities of grazing systems in northern Australia. Nine properties were selected, with each operating paddocks under at least 2 of the broad system types of interest – continuous, rotational and cell. Properties were located in both north and south Queensland and on either brigalow or eucalypt country. Paddocks within each of the grazing systems on each property were monitored for pasture attributes, soil surface condition, grazing days harvested, and diet quality of cattle between 2006 and 2009. The intensive systems on each property had been in place for up to 10 years prior to the project starting.
During the four-years of measurement, there were initially two or more years at each site of well below average rainfall followed by up to two average rainfall years. There was little or no impact of grazing system on pasture attributes or soil surface condition. Trends in pasture condition and growth were dominated by seasonal conditions, with pastures in all systems responding well to the better rainfall conditions towards the end of the project. Diet quality (measured by NIRS) was generally lower in the more intensive systems, especially during the growing season. There was no consistent difference in grazing days per ha due to grazing system.
The different grazing systems within a property were not managed independently of each other but tended to be operated as an integrated management system. This meant cattle could spend time within different systems within the one 12-month period, especially during dry years. In combination with differences in animal classes between systems at some sites, this precluded attempts to directly assess the impact of grazing system on individual animal productivity.
The integrated management of paddocks across systems on each property suggests that key management principles, such as matching stocking rate to carrying capacity, were applied to all paddocks on a property to a similar extent. This helps explain lack of impact of grazing system per se and supports the extensive evidence base that indicates stocking rate management, and not grazing system, is the major driver of pasture and animal productivity.