Good land condition pays premiums — The Central Australian story

Droughtmaster steer
High quality Droughtmaster steers are turned off at approximately 30 months of age from Old Man Plains.

Old Man Plains Research Station (OMP) turns off steers each year as part of the Quality Graze research project. This project aims to identify optimal grazing systems that can consistently produce premium beef in arid zone rangelands, despite the highly variable climate. Steers are grown out to 30 months of age before sending to slaughter around early April. From 2010-2019, high quality steers have been turned off every year, in both above and below average rainfall seasons. This consistency was largely due to having an appropriate stocking rate and good land condition.

With good land condition, even relatively small rainfall events will produce the useful green growth in pasture that steers need, to develop enough fat for Meat Standards Australia (MSA) grading. Provided the steers have access to enough nutritious dry grass, these fat reserves can be retained through to slaughter.

In May 2019, 41 per cent of steers branded in 2018 were on track with building fat reserves with P8 fat (a measure of fat depth at the P8 rump site) measuring 5 mm or greater; the minimum requirement to obtain MSA grading. By December 2019 this had dropped to 28 per cent. This was the first time there had been a decline in fat scores recorded in OMP steers since the Quality Graze project began in 2010. However, the low amount of rainfall received, was only part of the reason.

As anyone in the district will tell you, the prevailing conditions of the past two years have been dry to very dry (2018/19 and 2019/20), with very few growth events. A significant pasture growth event did occur in November 2018. This lead to the initial development of fat in the steers and provided abundant standing grass that would typically be both long-lasting and also capable of holding good nutritional value for up to two years. In Central Australia, while pastures can retain nutritional value for extended periods, this standing dry feed can be spoilt by rain. Generally, if there is enough rain to spoil standing dry feed, then it is also enough to promote new growth, although this is not always the case.

In May 2019 a small rain event caused more harm than good. A total of 12 mm fell over three days, generating very little new growth, while initiating deterioration of the nutritional quality in the remaining dry pasture. It is likely that this triggered the subsequent decline in fat deposits in the OMP steers.  A similar rainfall event of 15 mm occurred over three days in September, probably exacerbating the further deterioration of feed quality.

Central Australia felt the effects of a positive Indian Ocean Dipole well into January 2020, with no rainfall and persistent very hot weather. When the 2018 branded steers were assessed in late February 2020, a mere 8 per cent of the mob recorded a P8 fat score of 5 mm or greater. This decline related to declining feed quality and environmental stress. The steers were then turned out into a paddock that hadn’t been grazed for about nine months in preparation for trucking. At the same time, moderate falls of late summer rain (66 mm in late January/early February, followed by 30 mm at the beginning of March) provided a supply of fresh green pick in drainage lines and run-on areas. The steers benefited from this and by mid-April, 38 per cent had a P8 fat score of 5 mm or greater.

While originally targeted for sale in early April, the decision was made to hold the steers for an additional five weeks in the hope that the upward trend of P8 fat depth would continue.

The steers were slaughtered in late May 2020, with 71 per cent achieved a P8 fat score of 5 mm or greater. In total, 61 per cent of the herd achieved MSA grading which was a much better outcome than seemed possible in February.

On first inspection, the good final fat scores might seem to be just a result of the late summer rain turning things around. However, there is a more complex and much more significant story here.

The research program records detailed data on pasture as well as cattle production. Linking these together shows just how important good land condition is to get the most out of rain events.

The fat depth of steers decreased as pasture quality declined as a result of spoiling rain. The sharp increase in the percentage of the herd that had sufficient fat depth at the P8 site to meet MSA grading was due to the remarkable response of the pasture to late summer rainfall due to good land condition.

One of the key management activities at OMP is matching stocking rates to carrying capacity in order to maintain land condition. In this instance, good land condition maximised standing dry feed and sustained steer growth through two consecutive dry seasons. When the late rains came, the good land condition meant the country responded quickly with green pick. This nutritious young foliage, along with the feed reserved in the trucking paddock, enabled the steers to bounce back and the majority to be sold for premium prices.

Making the decision to reserve ungrazed feed can be difficult, particularly in dry years. However, on this occasion it provided the opportunity to hold steers for a little longer and achieve a much better return in an otherwise very dire-looking season.

Droughtmaster steers in forward store condition in yards. Mulga trees line the horizon.
Seventy-one per cent of the OMP steers slaughtered in late May 2020 had a P8 fat score of 5 mm or greater after only eight per cent met the MSA grading target only five weeks earlier.

For more information about this trial or other projects in the arid region, email Chris Materne (Pastoral Production Officer), Alison Kain (Pastoral Production Officer) or Meg Humphrys (Pastoral Extension Officer).