Shrubs Reduce Methane Burps in Livestock

Media Release via Mingenew Irwin Group.

2 June 2015

Open path laser measuring methane emissions from cattle at Irwin. Photo credit: Mingenew Irwin Group.
Open path laser measuring methane emissions from cattle at Irwin. Photo credit: Mingenew Irwin Group.

Recent research has shown that shrubs in the diet of sheep and cattle can reduce the methane emissions and increase profitability by up to 20%. Methane is a Green-House-Gas and is a by-product of fermentation in the gut. It is energy that is not utilised by livestock and is therefore released. To help reduce these emissions and utilise this energy, seven farmers across southern Australia each dedicated 20 ha of their land to plant shrubs. The three year project aimed to demonstrate that farmers can easily utilise shrubs in their grazing regimes.

Project officer for the Mingenew Irwin Group, Ms Donna Rayner explained that there were several other advantages to utilising shrubs in farming systems. They lower the risk of wind and water erosion, provide more effective water use, improve the microclimate, and creates habitat through the addition of diverse species and strata. The addition of native woody forage species can provide essential nutrients to grazing animals especially during periods of feed shortage. This in turn has the potential to increase farm profit and improve farm feed stability. Shrub systems can also provide shelter for livestock and may increase the soil carbon pool.

The ‘Shrubs for Emission Reduction and Carbon Reduction’ (SERCS) project has been working with farmers in WA, NSW and Victoria to establish the shrubs. The farms differed in climates, soil types, enterprises and farming systems. The project used a bottom-up approach to developing the project management plans for each farm. Ms Rayner said ‘The farmers worked in collaboration with researchers to select the species planted and the layout designs in terms of row spacing, pasture alley widths and the row orientations employed.’

The farmers are beginning to reap the rewards of their work by introducing their livestock into the shrub paddocks. Ms Rayner said “While some of the sheep and cattle have never experienced shrub as forage they are learning to incorporate them into the diet quickly.” The initial results indicate that the shrubs are recovering well from grazing.

The Irwin, WA site hosted CSIRO researchers who monitored the methane emissions from cattle using open path lasers. They set up two blocks with 52 cattle in each. The control group fed on pasture only while the SERCS group ate pasture and shrubs. The researchers found that there was no difference between the methane emission of the control group and the SERCS group. These results were encouraging because the shrubs were small and not fully established. It is anticipated that as the shrubs mature the farmers will be further rewarded.

Media Contact: Donna Rayner, PO Box 6, Mingenew WA 6530, Mob 0428 281 091, email donna@mig.org.au and www.mig.org.au

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