Effects of genetic and pasture adaptations to prime lamb systems on production and emissions

Effects of genetic and pasture adaptations to prime lamb systems on production and emissions

Whole farm systems analysis from the WFSAM project

Whole farm modelling was used to determine the effect of various on-farm management practices on emissions, meat and wool production, and emissions intensity (EI). The strategies fell into the categories of:

  • manipulating animal management or genotype
  • providing grain supplementation for young animals
  • altering soil fertility
  • altering pasture composition.

Most intervention strategies resulted in little change in EI, with the exception of reducing the joining age of maiden ewes from 19 months to 7 months, where EI was reduced by 11%. However, combining several improvements to current farm management had a larger effect. The combination of reducing maiden ewe joining age, increasing lamb weaning rate and improving animal feed-use efficiency led to a 17% reduction in EI.

The researchers found that imposing several beneficial strategies on farming systems simultaneously is more conducive to sustainable agricultural intensification compared with imposing any single intervention alone. The best strategies for both sustainably increasing production and reducing emissions intensity were those that decoupled the linkage between production and emissions, such as interventions that shifted the balance of the flock away from adults and towards juveniles while holding average annual stocking rates constant.

Key researchers

  • Matthew Harrison, Tasmanian Institute of Agriculture
  • Karen Christie, Tasmanian Institute of Agriculture
  • Alexandria Sinnett, Department of Economic Development, Jobs, Transport and Resources Victoria
  • Christie Ho, Department of Economic Development, Jobs, Transport and Resources Victoria

Publications

Harrison MT, Christie KM, Rawnsley RP, Eckard RJ (2014). Pasture management and livestock genotype interventions to improve whole farm productivity and reduce greenhouse gas emissions intensities. Animal Production Science, 54, 2018-2028, http://dx.doi.org/10.1071/AN14421.

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