Farm Table says:
Results from the Murrumbidgee Grain and Graze Project (2004-2008)
What was the problem?
Management of grazing wheats to help fill the autumn/winter feed gap, which is a common issue in the region.
What did the research involve?
What were the key findings?
Grazing and grain recovery
- Grazing can be successfully carried out at significantly higher stocking rates than traditionally recommended to utilise the high quantity of dry matter produced during winter.
- High stocking rates combined with long grazing periods (~ six weeks) reduced grain yields, but losses may be offset by income from additional liveweight gains, depending on prices. Stock should be removed before GS31 (stem elongation) to prevent yield losses.
- In drier seasons, limited trial data and anecdotal reports showed that grazing can result in higher grain yields, potentially due to water ‘saved’ from reduced leaf area then being available for grain fill later in the season. In wetter springs, yield losses from grazing can be limited by delayed maturity allowing the crop to utilise late rainfall.
- Grazing delayed flowering in winter wheats by up to 16 days, which can have implications for sowing times to manage frost/heat stress.
- The risk of wheat streak mosaic virus in early sown wheat crops has limited the adoption of dual purpose wheats in higher rainfall areas.
Liveweight responses
- Young sheep grazing dual purpose wheats showed significant liveweight gains when supplemented with NaCl (salt) and MgO (eg. Causmag) at a ratio of 1:1
- Sheep showed no grazing preferences between different wheat varieties.
- Grazing wheats showed high nutritive values that would not be expected to constrain animal growth rates
Final comment
High stocking rates combined with long grazing periods (~ six weeks) reduced grain yields, but losses may be offset by income from additional liveweight gains, depending on prices.
