Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Modelling pasture management and livestock genotype interventions to improve whole-farm productivity and reduce greenhouse gas emissions intensities

Matthew T. Harrison A C , Karen M. Christie A , Richard P. Rawnsley A and Richard J. Eckard B
+ Author Affiliations
- Author Affiliations

A Tasmanian Institute of Agriculture, University of Tasmania, Tas. 7320, Australia.

B Melbourne School of Land and Environment, University of Melbourne, Vic. 3010, Australia.

C Corresponding author. Email: Matthew.Harrison@utas.edu.au

Animal Production Science 54(12) 2018-2028 https://doi.org/10.1071/AN14421
Submitted: 19 March 2014  Accepted: 26 June 2014   Published: 29 August 2014

Abstract

Livestock greenhouse gas (GHG) emissions form the largest proportion of emissions from agriculture. Here we seek intervention strategies for sustainably intensifying the productivity of prime lamb enterprises without increasing net farm emissions. We apply a biophysical model and an emissions calculator to determine the implications of several interventions to a prime lamb farm in south-eastern Australia. We examine the effects of lamb liveweight or age at sale, weaning rate, maiden ewe joining age, genetic feed-use efficiency, supplementary grain feeding according to green pasture availability, soil fertility and botanical composition. For each intervention, stocking rates were optimised to the lesser of a minimum ground cover threshold or a maximum supplementary grain feeding threshold. Total animal production of the baseline farm was 478 kg clean fleece weight plus liveweight (CFW+LWT)/ha.annum and ranged from 166 to 609 kg CFW+LWT/ha.annum for interventions that replaced existing pastures with annual ryegrass or increased soil fertility respectively. Annual GHG emissions intensity of the baseline farm was 8.7 kg CO2-e/kg CFW+LWT and varied between 7.7 and 9.2 kg CO2-e/kg CFW+LWT for interventions that reduced maiden ewe joining age or increased sale liveweight, respectively. Stocking rate primarily governed total animal production, and in many cases production drove emissions, so interventions that increased production did not always reduce emissions intensity. Indeed, replacing existing perennial ryegrass/subterranean clover mixed pastures with perennial legume swards caused large reductions in both production and emissions, and interventions that increased soil fertility via phosphate addition caused large increases in production and emissions; as a consequence, both strategies had little effect on emissions intensity. Implementing several beneficial interventions simultaneously further increased production and reduced emissions intensity relative to implementing individual interventions alone. Baseline production increased by 61% by increasing soil fertility, improving feed-use efficiency and reducing the joining age of maiden ewes, while baseline emissions intensity was reduced by 17% by improving feed use efficiency, reducing the joining age of maiden ewes and supplementary grain feeding. We demonstrate that imposing several strategies on existing sheep farming systems simultaneously is more conducive to sustainable agricultural intensification than is imposing any single intervention alone, provided individual strategies were beneficial in their own right. The best strategies for both sustainably increasing production and reducing emissions intensity are those that decouple the linkage between production and emissions such as interventions that shift the balance of the flock away from adults and towards juveniles while holding average annual stocking rates constant.

Additional keywords: abatement, carbon farming, fertility, mitigation, model.


References

Alcock DJ, Hegarty RS (2011) Potential effects of animal management and genetic improvement on enteric methane emissions, emissions intensity and productivity of sheep enterprises at Cowra, Australia. Animal Feed Science and Technology 166–167, 749–760.
Potential effects of animal management and genetic improvement on enteric methane emissions, emissions intensity and productivity of sheep enterprises at Cowra, Australia.CrossRef |

Alcock DJ, Harrison MT, Cullen BR, Rawnsley RP, Eckard RJ (2014) Can animal genetics and flock management be used to reduce greenhouse gas emissions but also maintain productivity of wool-producing enterprises? Agricultural Systems
Can animal genetics and flock management be used to reduce greenhouse gas emissions but also maintain productivity of wool-producing enterprises?CrossRef | in press.

Beauchemin KA, Henry Janzen H, Little SM, McAllister TA, McGinn SM (2010) Life cycle assessment of greenhouse gas emissions from beef production in western Canada: a case study. Agricultural Systems 103, 371–379.
Life cycle assessment of greenhouse gas emissions from beef production in western Canada: a case study.CrossRef |

Blaxter KL, Clapperton JL (1965) Prediction of the amount of methane produced by ruminants. The British Journal of Nutrition 19, 511–522.
Prediction of the amount of methane produced by ruminants.CrossRef | 1:CAS:528:DyaF28XitFKktg%3D%3D&md5=cce47ad397fedf3bced4f69441c525dfCAS | 5852118PubMed |

Browne NA, Eckard RJ, Behrendt R, Kingwell RS (2011) A comparative analysis of on-farm greenhouse gas emissions from agricultural enterprises in south eastern Australia. Animal Feed Science and Technology 166–167, 641–652.
A comparative analysis of on-farm greenhouse gas emissions from agricultural enterprises in south eastern Australia.CrossRef |

Cottle DJ, Nolan JV, Wiedemann SG (2011) Ruminant enteric methane mitigation: a review. Animal Production Science 51, 491–514.
Ruminant enteric methane mitigation: a review.CrossRef | 1:CAS:528:DC%2BC3MXntVGisLY%3D&md5=5199c518bcbf607cd2261a9a90b2975eCAS |

Crosson P, Shalloo L, O’Brien D, Lanigan GJ, Foley PA, Boland TM, Kenny DA (2011) A review of whole farm systems models of greenhouse gas emissions from beef and dairy cattle production systems. Animal Feed Science and Technology 166–167, 29–45.
A review of whole farm systems models of greenhouse gas emissions from beef and dairy cattle production systems.CrossRef |

Cruickshank GJ, Thomson BC, Muir PD (2008) Modelling management change on production efficiency and methane output within a sheep flock. Final report June 2008. Sustainable land management and climate change. Ministry of Agriculture and Forestry, Wellington, New Zealand.

DCCEE (2012) ‘National Inventory Report 2010: the Australian Government Submission to the UN Framework Convention on Climate Change April 2012.’ (Department of Climate Change and Energy Efficiency: Canberra)

Eckard RJ, Grainger C, de Klein CAM (2010) Options for the abatement of methane and nitrous oxide from ruminant production: a review. Livestock Science 130, 47–56.
Options for the abatement of methane and nitrous oxide from ruminant production: a review.CrossRef |

Freer M, Moore AD, Donnelly JR (2012) The GRAZPLAN animal biology model for sheep and cattle and the GrazFeed decision support tool. CSIRO, Canberra. Available at http://www.grazplan.csiro.au/?q=node/15 [Verified 24 August 2014].

Ghahramani A, Moore AD (2013) Climate change and broadacre livestock production across southern Australia. 2. Adaptation options via grassland management. Crop and Pasture Science 64, 615–630.
Climate change and broadacre livestock production across southern Australia. 2. Adaptation options via grassland management.CrossRef |

Harrison MT, Evans JR, Dove H, Moore AD (2011) Recovery dynamics of rainfed winter wheat after livestock grazing 1. Growth rates, grain yields, soil water use and water-use efficiency. Crop & Pasture Science 62, 947–959.

Harrison MT, Evans JR, Moore AD (2012a) Using a mathematical framework to examine physiological changes in winter wheat after livestock grazing: 1. Model derivation and coefficient calibration. Field Crops Research 136, 116–126.

Harrison MT, Evans JR, Moore AD (2012b) Using a mathematical framework to examine physiological changes in winter wheat after livestock grazing: 2. Model validation and effects of grazing management. Field Crops Research 136, 127–137.

Harrison MT, Jackson T, Cullen BR, Rawnsley RP, Ho C, Cummins L, Eckard RJ (2014) Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities. 1. Sheep production and emissions intensities. Agricultural Systems 131C, 23–33.
Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities. 1. Sheep production and emissions intensities.CrossRef |

Hegarty RS, Alcock D, Robinson DL, Goopy JP, Vercoe PE (2010) Nutritional and flock management options to reduce methane output and methane per unit product from sheep enterprises. Animal Production Science 50, 1026–1033.
Nutritional and flock management options to reduce methane output and methane per unit product from sheep enterprises.CrossRef | 1:CAS:528:DC%2BC3cXhsVGrt7fJ&md5=28fa20ad5a1964bee23f6f207b890e66CAS |

Herrero M, Thornton PK (2013) Livestock and global change: emerging issues for sustainable food systems. Proceedings of the National Academy of Sciences, USA 110, 20 878–20 881.
Livestock and global change: emerging issues for sustainable food systems.CrossRef | 1:CAS:528:DC%2BC2cXnsFykug%3D%3D&md5=b559689a0bd1e5b6318858c01d8ee12aCAS |

Ho C, Jackson T, Harrison MT, Eckard RJ (2014) Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities: 2. Economic performance. Animal Production Science 54, 1248–1253.
Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities: 2. Economic performance.CrossRef | 1:CAS:528:DC%2BC2cXhtlaktLjL&md5=df6f677e455b8ae0eccc702e7e150893CAS |

Hristov AN, Ott T, Tricarico J, Rotz A, Waghorn G, Adesogan A, Dijkstra J, Montes F, Oh J, Kebreab E, Oosting SJ, Gerber PJ, Henderson B, Makkar HPS, Firkins JL (2013) SPECIAL TOPICS – Mitigation of methane and nitrous oxide emissions from animal operations: III. A review of animal management mitigation options. Journal of Animal Science 91, 5095–5113.
SPECIAL TOPICS – Mitigation of methane and nitrous oxide emissions from animal operations: III. A review of animal management mitigation options.CrossRef | 1:CAS:528:DC%2BC3sXhslKktrvJ&md5=843efbea29f3d9ff1a8b700d4dea6813CAS | 24045470PubMed |

IPCC (2013) Working group I contribution to the IPCC fifth assessment report climate change 2013: the physical science basis. Chapter 10: detection and attribution of climate change: from global to regional – final draft underlying scientific-technical assessment. Available at http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter10.pdf [Verified 13 December 2013]

Mokany K, Moore AD, Graham P, Simpson RJ (2010) Optimal management of fertiliser and stocking rate in temperate grazing systems. Animal Production Science 50, 6–16.
Optimal management of fertiliser and stocking rate in temperate grazing systems.CrossRef |

Moore AD, Harrison MT (2011) MLA SBP.0073 final milestone report 2012–05 for southern livestock adaptation project. Appendix 10. Improving and extending the parameter sets for the GRAZPLAN pasture model. CSIRO, Canberra. Available at http://sla2030.net.au/wp-content/uploads/2013/02/CSIRO-Appendix-10. Improving-and-extending-the-parameter-sets-for.pdf.

Moore AD, Donnelly JR, Freer M (1997) GRAZPLAN: decision support systems for Australian grazing enterprises. 3. Pasture growth and soil moisture submodels, and the GrassGro DSS. Agricultural Systems 55, 535–582.
GRAZPLAN: decision support systems for Australian grazing enterprises. 3. Pasture growth and soil moisture submodels, and the GrassGro DSS.CrossRef |

Perry RJ (1996) Soil survey of the Bulart Region, south-eastern Dundas Tablelands. BSc (Hons) Thesis, University of Ballarat, Ballarat, Vic.

UN 2013. United Nations, Department of Economic and Social Affairs. Population division, population estimates and projections section. Medium variant world population. Available at http://esa.un.org/unpd/wpp/unpp/p2k0data.asp [Verified 13 December 2013]



Rent Article (via Deepdyve) Export Citation Cited By (1)