Grazing Cereals

With the shortage of both pasture and supplementary feed in some areas of the state, farmers are considering, or are already, grazing their cereal crops to provide feed for livestock. Management of this grazing will depend on whether you are just grazing until pasture growth improves, sacrificing a crop paddock for feed or you are planning to harvest a crop.
There are a number of things to consider to avoid significantly reducing the yield of a cereal crop.

  • Graze barley crops first. Barley produces more rapid early vegetative growth than wheat, so will generally give the most amount of feed. To minimise grain losses grazing will need to cease by mid-July in the low rainfall cropping zones.
  • Grazing wheat. In many wheat crops this year, warm temperatures has resulted in rapid development with limited tillering and lower than normal dry matter production. There is the opportunity to graze a paddock or two to delay maturity, increase biomass production (but this is reliant on high soil N or application) or defer some soil water use. The decision to graze these paddocks needs to be made post haste so that the number of potential heads grazed is zero, or at least limited.
  • Check herbicide withholding periods. The grazing withholding period (GWP) is the minimum time between chemical application and harvest for stockfeed or grazing to ensure the maximum reside limit (MRL) and/or export grazing interval (EGI) are not exceeded.
  • Check that crops are anchored. Before putting the livestock in, check that crops have developed a good root system to stop them being pulled out of the ground. They are generally anchored at about the 3 to 5 leaf stage but this will vary depending on soil type.
  • Grazing strategies. High grazing pressure will ensure that crops are grazed more evenly and will avoid stock camping, which will bare areas out. This can be achieved by using large mobs and/or splitting paddocks.
    Grazing crops is best done with electric or temporary fencing, so that each paddock is split in half irrespective of its size or stocking rate. This also allows more discretion about the duration of grazing – be it a ‘clip’ grazing so that there is enough leaf left for rapid recovery or erosion minimisation.
  • Timing of grazing to minimize yield losses. In lower rainfall areas grazing after mid-July will increase the risk of yield losses, however in medium and higher rainfall areas crops can be grazed until late July.
  • When to stop grazing.
    • In low rainfall areas remove stock when the crop gets to mid to late tillering. This will leave sufficient time for the crop to recover and produce grain.
    • In higher rainfall areas crops can be grazed up until stem elongation. Establish a small exclusion area to monitor crop development.
  • Maintain groundcover.If using crops for sheep feed ensure some residue is left to ensure regrowth and reduce the risk of erosion.
  • Animal health issues to consider. It is important to supplement stock with a source of calcium, salt and magnesium continually while grazing and to vaccinate for pulpy kidney prior.

For more information contact your local Livestock Consultant or Agronomist or refer to the SheepConnect SA website.
Acknowledgements to Michael Wurst, PIRSA and Mick Faulkner, Agrilink Agricultural Consultants for contributing the content for this article.
SheepConnect SA is supported by Australian Wool Innovation Ltd., the SA Sheep Industry Fund and Primary Industries and Regions SA.