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Life-cycle assessment of the intensity of production on the greenhouse gas emissions and economics of grass-based suckler beef production systems

  • A. M. CLARKE (a1), P. BRENNAN (a2) and P. CROSSON (a1)


In Ireland, the largest contributor of greenhouse gas (GHG) emissions is agriculture. The objective of the current study was to evaluate the impact of stocking intensities of beef cattle production systems on technical and economic performance and GHG emissions. A bioeconomic model of Irish suckler beef production systems was used to generate scenarios and to evaluate their technical and economic performance. To model the impact of each scenario on GHG emissions, the output of the bioeconomic model was used as an inventory analysis in a life-cycle assessment model and various GHG emission factors were integrated with the production profile. All the estimated GHG emissions were converted to their 100-year global warming potential carbon dioxide equivalent (CO2e). The scenarios modelled were bull/heifer and steer/heifer suckler beef production systems at varying stocking intensities. According to policy constraints, stocking intensities were based on the excretion of organic nitrogen (N), which varied depending on animal category. Stocking intensity was increased by increasing fertilizer N application rates. Carcass output and profitability increased with increasing stocking intensity. At a stocking intensity of 150 kg N/ha total emissions were lowest when expressed per kg of beef carcass (20·1 kg CO2e/kg beef) and per hectare (9·2 tCO2e/ha) in the bull/heifer system. Enteric fermentation was the greatest source of GHG emissions and ranged from 0·49 to 0·47 of total emissions with increasing stocking intensity for both production systems. The current study shows that increasing stocking intensity via increased fertilizer N application rates leads to increased profitability on beef farms with only modest increases in GHG emissions.


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Baudracco, J., Lopez-Villalobos, N., Romero, L. A., Scandolo, D., Maceil, M., Comeron, E. A., Holmes, C. W. & Barry, T. N. (2011). Effects of stocking rate on pasture production, milk production and reproduction of supplemented crossbred Holstein–Jersey dairy cows grazing lucerne pasture. Animal Feed Science and Technology 168, 131143.
Beauchemin, K. A., Janzen, H. H., Little, S. M., Mcallister, T. A. & Mcginn, S. M. (2010). Life cycle assessment of greenhouse gas emissions from beef production in western Canada: a case study. Agricultural Systems 103, 371379.
Breen, J., Donnellan, T., Hanrahan, K., Gillespie, P., Miller, C. & O'Donoghue, C. (2010 a). Economic issues associated with greenhouse gas emission reductions in Ireland (abstract). In A Climate for Change. Opportunities for Carbon-Efficient Farming. International Conference organised by the Teagasc, GHG working group. Dublin, 24–25 June, 2010, p. 9. Carlow, Ireland: Teagasc.
Breen, J. P., Donnellan, T. & Westhoff, P. (2010 b). Food for thought: EU climate change policy presents new challenges for agriculture. EuroChoices 9, 2429.
Burney, J. A., Davis, S. J. & Lobell, D. B. (2010). Greenhouse gas mitigation by agricultural intensification. Proceedings of the National Academy of Science USA 107, 1205212057.
Carbon Trust (2010). Footprint Expert™. Model Framework, Reference Database and Calculators. Footprint Expert v.3.1 July 2010. London: Carbon Trust Footprinting Company.
Casey, J. W. & Holden, N. M. (2006). Greenhouse gas emissions from conventional, agri-environmental scheme, and organic Irish suckler-beef units. Journal of Environmental Quality 35, 231239.
Clarke, A. M., Drennan, M. J., Mcgee, M., Kenny, D. A., Evans, R. D. & Berry, D. P. (2009). Intake, growth and carcass traits in male progeny of sires differing in genetic merit for beef production. Animal 3, 791801.
Connolly, L., Kinsella, A., Quinlan, G. & Moran, B. (2006). National Farm Survey 2005. Athenry, Co. Galway, Ireland: Teagasc. Available from:'05.pdf (verified 1 May 2013).
Crosson, P. (2008). The impact of cow genotype on the profitability of grassland-based suckler beef production in Ireland. In Biodiversity and Animal Feed: Future Challenges for Grassland Production. Proceedings of the 22nd Annual Meeting of the European Grassland Federation, Uppsala, Sweden, 9–12 June 2008 (Eds Hopkins, N., Gustafsson, T., Bertilsson, J., Dalin, G., Nilsdotter-Linde, N. & Spörndly, E.), pp. 771773. Grassland Science in Europe vol. 13. Uppsala, Sweden: SLU.
Crosson, P. & Mcgee, M. (2011). Suckler beef production in Ireland: challenges and opportunities. In Proceedings of the National Beef Conference, 5th April 2011, Kilkenny, Ireland. pp. 2942. Carlow, Ireland: Teagasc. Available from: (verified 22 April 2013).
Crosson, P., O'Kiely, P., O'Mara, F. P. & Wallace, M. (2006). The development of a mathematical model to investigate Irish beef production systems. Agricultural Systems 89, 349370.
Crosson, P., O'Kiely, P., O'Mara, F. & Wallace, M. (2007). Optimal beef production system in differing concentrate price and grass utilisation scenarios. In Proceedings of the Agricultural Research Forum 2007. p. 51. Carlow, Ireland: Teagasc. Available from: (verified 22 April 2013).
Crosson, P., Shalloo, L., O'Brien, D., Lanigan, G. J., Foley, P. A., Boland, T. M. & Kenny, D. A. (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, 2945.
Dalgaard, T., Halberg, N. & Porter, J. R. (2001). A model for fossil energy use in Danish agriculture used to compare organic and conventional farming. Agriculture, Ecosystems and Environment 87, 5165.
De Klein, C. A. M. & Eckard, R. J. (2008). Targeted technologies for nitrous oxide abatement from animal agriculture. Australian Journal of Experimental Agriculture 48, 1420.
Drennan, M. J. & Mcgee, M. (2009). Performance of spring-calving beef suckler cows and their progeny to slaughter on intensive and extensive grassland management systems. Livestock Science 120, 112.
Drennan, M. J., Mcgee, M. & Keane, M. G. (2005). Post-weaning performance and carcass characteristics of steer progeny from different suckler cow breed types. Irish Journal of Agriculture and Food Research 44, 195204.
Ecoinvent (2010). Ecoinvent 2.0 Database. St-Gallen, Switzerland: Centre for Life Cycle Inventories. Retrieved from: (verified 5 July 2011).
Environmental Protection Agency (EPA) (1990). Methane emissions and opportunities for control. In Workshop Results of Intergovernmental Panel on Climate Change, EPA/400/9-90/007. Washington, D.C.: US EPA.
Environmental Protection Agency (EPA) (2011). Ireland's Greenhouse Gas Emissions Projections 2010–2020. Wexford, Ireland: EPA.
Environmental Protection Agency (EPA) (2013). Ireland's Greenhouse Gas Emissions in 2011. 15 April 2013. Wexford, Ireland: EPA. Available from: (verified 1 May 2013).
Fales, S. L., Muller, L. D., Ford, S. A., O'Sullivan, M., Hoover, R. J., Holden, L. A., Lanyon, L. E. & Buckmaster, D. R. (1995). Stocking rate affects production and profitability in a rotationally grazed pasture system. Journal of Production Agriculture 8, 8896.
Foley, P. A., Crosson, P., Lovett, D. K., Boland, T. M., O'Mara, F. P. & Kenny, D. A. (2011). Whole-farm systems modelling of greenhouse gas emissions from pastoral suckler beef cow production systems. Agriculture, Ecosystems and Environment 142, 222230.
Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M. & Van Dorland, R. (2007). Changes in atmospheric constituents and in radiative forcing. In Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Eds Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M. & Miller, H. L.), pp. 129234. Cambridge, UK & New York: Cambridge University Press.
French, P., O'Donovan, M., Horan, B. & Shalloo, L. (2010). What is the optimum stocking rate to maximize profitability of grass based milk production? Irish Grassland Association Journal 44, 1622.
Hennessy, T., Kinsella, A., Moran, B. & Quinlan, G. (2012). National Farm Survey 2011. Athenry, Co. Galway, Ireland: Teagasc.
Horan, B., Mccarthy, B. & Brennan, A. (2012). The Effect of Stocking Rate and Calving Date on the Characteristics of Milk Production Systems Post Milk Quotas. Moorepark, Fermoy, Ireland: Teagasc. Available under ‘Curtins – a Review’ at: (verified 22 April 2013).
Howley, M., O'Leary, F. & O'Gallachoir, B. (2007). Energy in Ireland 1990–2006. 2007 Report. Dublin, Ireland: Sustainable Energy Ireland. Available from: (verified 22 April 2013).
Hyde, B., Carton, O. & Murphy, W. (2008). Farm Facility Survey 2003. Report prepared for the Department of Agriculture by Teagasc Johnstown Castle, Co. Wexford, Ireland. Wexford, Ireland: Teagasc.
Intergovernmental Panel on Climate Change (IPCC) (2006). Guidelines for National Greenhouse Gas Inventories (Eds Eggleston, H. S., Buendia, L., Miwa, K., Ngara, T. & Tanabe, K.). Prepared by the National Greenhouse Gas Inventories Programme. Kanagawa, Japan: IGES.
International Organisation of Standardisation (ISO) (2006). Environmental Management – Life Cycle Assessment: Principles and Framework. (ISO 14040:2006). Geneva, Switzerland: ISO.
Jarrige, R. (1989). Ruminant Nutrition. Recommended Allowances and Feed Tables. London: John Libbey Eurotext.
Kennedy, E., O' Donovan, M., Murphy, J. P., O'Mara, F. P. & Delaby, L. (2006). The effect of initial spring grazing date and subsequent stocking rate on the grazing management, grass dry matter intake and milk production of dairy cows in summer. Grass and Forage Science 61, 375384.
Kennedy, E., O' Donovan, M., Murphy, J. P., Delaby, L. & O'Mara, F. P. (2007). Effect of spring grazing date and stocking rate on sward characteristics and dairy cow production during midlactation. Journal of Dairy Science 90, 20352046.
Lothe, K., Fuchs, C. & Zeddies, J. (1997). Reductions of emissions in farming systems in Germany. In Climate Change Mitigation and European Land Use Policies (Eds Adger, W. N., Pettenella, D. & Whitby, M.), pp. 159169. Wallingford, UK: CAB International.
Luo, J., De Klein, C. A. M., Ledgard, S. F. & Saggar, S. (2010). Management options to reduce nitrous oxide emissions from intensively grazed pastures: a review. Agriculture, Ecosystems and Environment 136, 282291.
Macdonald, K. A., Penno, J. W., Nicholas, P. K., Lile, J. A., Coulter, M. & Lancaster, J. A. S. (2001). Farm systems-impact of stocking rate on dairy farm efficiency. Proceedings of the New Zealand Grassland Association 63, 223227.
Macdonald, K. A., Penno, J. W., Lancaster, J. A. S. & Roche, J. R. (2008). Effect of stocking rate on pasture production, milk production and reproduction of dairy cows in pasture-bases systems. Journal of Dairy Science 91, 21512163.
Microsoft Corporation (2000). Microsoft Excel. Redmond, WA, USA: Microsoft Corporation. Available from: (verified 23 April 2013).
Mcgettigan, M., Duffy, P. & Hyde, B. (2009). Ireland Informative Inventory Report 2009. Air pollutant emissions in Ireland 1990–2007. Reported to the Secretariat of the UNECE Convention on Long Range Transboundary Air Pollution. Wexford, Ireland: EPA.
Mcgettigan, M., Duffy, P., Hyde, B., Hanley, E., O'Brien, P., Ponzi, J. & Black, K. (2010). Ireland National Inventory Report 2010. Greenhouse Gas Emissions 1990–2008. Reported to The United Nations Framework Convention on Climate Change. Wexford, Ireland: Environmental Protection Agency.
Murphy, B. M., Drennan, M. J., O' Mara, F. P. & Mcgee, M. (2008 a). Performance and feed intake of five beef suckler cow genotypes and pre-weaning growth of their progeny. Irish Journal of Agricultural and Food Research 47, 1325.
Murphy, B. M., Drennan, M. J., O' Mara, F. P. & Mcgee, M. (2008 b). Post-weaning growth, ultrasound and skeletal measurements, muscularity scores and carcass traits and composition of progeny of five beef suckler cow genotypes. Irish Journal of Agricultural and Food Research 47, 2740.
Neufeldt, H., Schafer, M., Angenendt, E., Li, C., Kaltschmitt, M. & Zeddies, J. (2006). Disaggregated greenhouse gas emission inventories from agriculture via a coupled economic-ecosystem model. Agriculture, Ecosystems and Environment 112, 233240.
Nguyen, T. L. T., Hermansen, J. E. & Mogensen, L. (2010). Environmental consequences of different beef production systems in the EU. Journal of Cleaner Production 18, 756766.
OECD/FAO (2012). OECD/FAO Agricultural Outlook 2012–2021. Paris, France & Rome: OECD Publishing and FAO. Available from: (verified 23 April 2013).
O'Mara, F. P., Caffery, P. J. & Drennan, M. J. (1997). Net energy values of grass silage determined from comparative feeding trials. Irish Journal of Agricultural and Food Research 36, 110.
Pelletier, N., Pirog, R. & Rasmussen, R. (2010). Comparative life cycle environmental impacts of three beef production strategies in the Upper Midwestern United States. Agricultural Systems 103, 380389.
Peters, G. M., Rowley, H. V., Wiedemann, S., Tucker, R., Short, M. D. & Schulz, M. (2010). Red meat production in Australia: life cycle assessment and comparison with overseas studies. Environmental Science and Technology 44, 13271332.
Pre Consultants (2012). SimaPro 7.2 method. In Database Manual. Amersfoort, The Netherlands: Pré Consultants B.V.
Rotz, C. A., Mertens, D. R., Buckmaster, D. R., Allen, M. S. & Harrison, J. H. (1999). A dairy herd model for use in whole farm simulations. Journal of Dairy Science 82, 28262840.
Roy, P., Orikasa, T., Thammawong, M., Nakamura, N., Xu, Q. & Shiina, T. (2012). Life cycle of meats: an opportunity to abate the greenhouse gas emission from meat industry in Japan. Journal of Environmental Management 93, 218224.
Schulte, R. & Donnellan, T. (Eds) (2012). A Marginal Abatement Cost Curve for Irish Agriculture. Teagasc submission to the National Climate Policy Development Consultation. Carlow, Ireland: Teagasc.
Schulte, R. P. O., Lanigan, G. & Gibson, M. (Eds) (2011). Irish Agriculture, Greenhouse Gas Emission and Climate Change, Opportunities, Obstacles and Proposed Solutions. Teagasc working group on greenhouse gas emissions. Carlow, Ireland: Teagasc.
Shalloo, L., O' Donnell, S. & Horan, B. (2007). Profitable dairying in an increased EU milk quota scenario. In Exploiting the Freedom to Milk: Proceedings of the National Dairy Conferences 2007, 21–22 November 2007, Kilkenny and Mayo, pp. 2044. Carlow, Ireland: Teagasc.
Steen, R. W. J. (1995). The effect of plane of nutrition and slaughter weight on growth and food efficiency in bulls, steers and heifers of three breed crosses. Livestock Production Science 42, 111.
Stewart, A. A., Little, S. M., Ominski, K. H., Wittenberg, K. M. & Janzen, H. H. (2009). Evaluating greenhouse gas mitigation practices in livestock systems: an illustration of a whole-farm approach. Journal of Agricultural Science, Cambridge 147, 367382.
Tilman, D., Balzer, C., Hill, J. & Befort, B. L. (2010). Global food demand and the sustainable intensification of agriculture. Proceedings of the National Academy of Sciences USA 108, 2026020264.
Veysset, P., Lherm, M. & Bebin, D. (2010). Energy consumption, greenhouse gas emissions and economic performance assessments in French Charolais suckler cattle farms: model-based analysis and forecasts. Agricultural Systems 103, 4150.
Weissbach, F. & Peters, G. (1983). Quantity, chemical composition and feed value of silage effluent. Feldwirtschaft 24, 7881.
White, T. A., Snow, V. O. & King, W. M. C. G. (2010). Intensification of New Zealand beef farming systems. Agricultural Systems 103, 2135.
Wims, C. M., Deighton, M. H., Lewis, E., O'Loughlin, B., Delaby, L., Boland, T. M. & O'Donovan, M. (2010). Effect of pregrazing herbage mass on methane production, dry matter intake, and milk production of grazing dairy cows during the mid-season period. Journal of Dairy Science 93, 49764985.
Wood, S. & Cowie, A. (2004). A Review of Greenhouse Gas Emission Factors for Fertiliser Production. For IEA Bioenergy Task 38. Research and Development Division, State Forests of New South Wales, Cooperative Research Centre for Greenhouse Gas Accounting. Paris, France: IEA. Available from: (verified 21 December 2012).
Yan, T., Agnew, R. E., Gordon, F. J. & Porter, M. G. (2000). Prediction of methane energy output in dairy and beef cattle offered grass silage-based diets. Livestock Production Science 64, 253263.
Yan, T., Frost, J. P., Keady, T. W., Agnew, R. E. & Mayne, C. S. (2007). Prediction of nitrogen excretion in faeces and urine of beef cattle offered diets containing grass silage. Journal of Animal Science 85, 19821989.
Yan, T., Porter, M. G. & Mayne, C. S. (2009). Prediction of methane emission from beef cattle using data measured in indirect open-circuit respiration calorimeters. Animal 3, 14551462.


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