Abberton, MT, Marshall, AH, Humphreys, MW, Macduff, JH, Collins, RP, Marley, CL, Donald, LS 2008. Genetic improvement of forage species to reduce the environmental impact of temperate livestock grazing systems. Advances in Agronomy 98, 311–355.
Alexandratos, N, Bruinsma, J 2012. World agriculture towards 2030/2050: the 2012 revision. ESA Working Paper No. 12-03, FAO, Rome.
Amani, P, Schiefer, G 2011. Review on suitability of available LCIA methodologies for assessing environmental impact of the food sector. International Journal on Food System Dynamics 2, 194–206.
Arsenault, N, Tyedmers, P, Fredeen, A 2009. Comparing the environmental impacts of pasture-based and confinement-based dairy systems in Nova Scotia (Canada) using life cycle assessment. International Journal of Agricultural Sustainability 7, 19–41.
Basset-Mens, C, van der Werf, HMG 2005. Scenario-based environmental assessment of farming systems: the case of pig production in France. Agriculture, Ecosystems and Environment 105, 127–144.
Basset-Mens, C, Kelliher, F, Ledgard, S, Cox, N 2009. Uncertainty of global warming potential for milk production on a New Zealand farm and implications for decision making. The International Journal of Life Cycle Assessment 14, 630–638.
Beauchemin, KA, Janzen, HH, 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.
Beauchemin, KA, Janzen, HH, Little, SM, McAllister, TA, McGinn, SM 2011. Mitigation of greenhouse gas emissions from beef production in western Canada – evaluation using farm-based life cycle assessment. Animal Feed Science and Technology 166-67, 663–677.
Belflower, JB, Bernard, JK, Gattie, DK, Hancock, DW, Risse, LM, Alan Rotz, C 2012. A case study of the potential environmental impacts of different dairy production systems in Georgia. Agricultural Systems 108, 84–93.
Bell, MJ, Eckard, RJ, Cullen, BR 2012. The effect of future climate scenarios on the balance between productivity and greenhouse gas emissions from sheep grazing systems. Livestock Science 147, 126–138.
Bell, MJ, Wall, E, Russell, G, Simm, G, Stott, AW 2011. The effect of improving cow productivity, fertility, and longevity on the global warming potential of dairy systems. Journal of Dairy Science 94, 3662–3678.
Bindi, M, Olesen, JE 2011. The responses of agriculture in Europe to climate change. Regional Environmental Change 11, 151–158.
Bouwman, L, Goldewijk, KK, Van Der Hoek, KW, Beusen, AHW, Van Vuuren, DP, Willems, J, Rufino, MC, Stehfest, E 2011. Exploring global changes in nitrogen and phosphorus cycles in agriculture induced by livestock production over the 1900–2050 period. Proceedings of the National Academy of Sciences. doi:10.1073/pnas.1012878108.
Bryant, JR, Snow, VO 2008. Modelling pastoral farm agro-ecosystems: a review. New Zealand Journal of Agricultural Research 51, 349–363.
Casey, JW, Holden, NM 2006. Quantification of GHG emissions from sucker-beef production in Ireland. Agricultural Systems 90, 79–98.
Chardon, X, Rigolot, C, Baratte, C, Espagnol, S, Raison, C, Martin-Clouaire, R, Rellier, J-P, Le Gall, A, Dourmad, JY, Piquemal, B, Leterme, P, Paillat, JM, Delaby, L, Garcia, F, Peyraud, JL, Poupa, JC, Morvan, T, Faverdin, P 2012. MELODIE: a whole-farm model to study the dynamics of nutrients in dairy and pig farms with crops. Animal 6, 1711–1721.
Chatskikh, D, Olesen, JE, Berntsen, J, Regina, K, Yamulki, S 2005. Simulation of effects of soils, climate and management on N2O emission from grasslands. Biogeochemistry 76, 395–419.
Colomb, V, Bernoux, M, Bockel, L, Chotte, JL, Martin, S, Martin-Phipps, C, Mousset, J, Tinlot, M, Touchemoulin, O 2012. Review of GHG calculators in agriculture and forestry sectors. A Guideline and Appropriate Choice and Use of Landscape Based Tools. Retrieved October 2, 2012, from http://www.fao.org/fileadmin/templates/ex_act/pdf/Review_existingGHGtool_FR.pdf
Cowie, A, Eckard, R, Eady, S 2012. Greenhouse gas accounting for inventory, emissions trading and life cycle assessment in the land-based sector: a review. Crop and Pasture Science 63, 284–296.
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, 29–45.
Cullen, BR, Eckard, RJ 2011. Impacts of future climate scenarios on the balance between productivity and total greenhouse gas emissions from pasture based dairy systems in south-eastern Australia. Animal Feed Science and Technology 166–167, 721–735.
De Boer, IJM, Cederberg, C, Eady, S, Gollnow, S, Kristensen, T, Macleod, M, Meul, M, Nemecek, T, Phong, LT, Thoma, G, van der Werf, HMG, Williams, AG, Zonderland-Thomassen, MA 2011. Greenhouse gas mitigation in animal production: towards an integrated life cycle sustainability assessment. Current Opinion in Environmental Sustainability 3, 423–431.
De Klein, CAM, Smith, LC, Monaghan, RM 2006. Restricted autumn grazing to reduce nitrous oxide emissions from dairy pastures in Southland, New Zealand. Agriculture, Ecosystems and Environment 112, 192–199.
De Vries, M, de Boer, IJM 2010. Comparing environmental impacts for livestock products: a review of life cycle assessments. Livestock Science 128, 1–11.
Del Grosso, S, Ojimaa, D, Parton, W, Mosier, A, Peterson, G, Schimel, D 2002. Simulated effects of dryland cropping intensification on soil organic matter and greenhouse gas exchanges using the DAYCENT ecosystem model. Environmental Pollution 116 (supp. 1), S75–S83.
Del Prado, A, Scholefield, D 2008. Use of SIMSDAIRY modelling framework system to compare the scope on the sustainability of a dairy farm of animal and plant genetic-based improvements with management-based changes. The Journal of Agricultural Science 146, 195–211.
Del Prado, A, Misselbrook, T, Chadwick, DR, Newbold, CJ 2011b. Nitrogen co-benefits and trade-offs of novel CH4 mitigation measures applied on livestock systems. In Nitrogen and global change: key findings – future challenges, Edinburgh, UK. Retrieved October 2, 2012, from http://nitrogen.ceh.ac.uk/nitrogen2011/_oral_presentations/S4_4_delPrado.pdf
Del Prado, A, Mas, K, Pardo, G, Gallejones, P 2013. Modelling the interactions between C and N farm balances and GHG emissions from confinement dairy farms in northern Spain. Science of the Total Environment (in press).
Del Prado, A, Chadwick, D, Cardenas, L, Misselbrook, T, Scholefield, D, Merino, P 2010. Exploring systems responses to mitigation of GHG in UK dairy farms. Agriculture Ecosystems and Environment 136, 318–332.
Del Prado, A, Shepherd, A, Wu, L, Topp, C, Moran, D, Tolkamp, B, Chadwick, D 2009. Modelling the effect of climate change on environmental pollution losses from dairy systems in the UK. BC3 Working Paper Series 2009-07. Basque Centre for Climate Change (BC3), Bilbao, Spain.
Del Prado, A, Misselbrook, T, Chadwick, D, Hopkins, A, Dewhurst, RJ, Davison, P, Butler, A, Schröder, J, Scholefield, D 2011a. SIMSDAIRY: a modelling framework to identify sustainable dairy farms in the UK. Framework description and test for organic systems and N fertiliser optimisation. Science of the Total Environment 409, 3993–4009.
Denef, K, Paustian, K, Archibeque, S, Biggar, S, Pape, D 2012. Report of greenhouse gas accounting tools for agriculture and forestry sectors. Interim Report to USDA under Contract No. GS-23F-8182H. Retrieved October 2, 2012, from http://www.commerce.wa.gov/DesktopModules/CTEDPublications/CTEDPublicationsView.aspx?tabID=0&ItemID=7797&MId=944&wversion=Staging
Dijkstra, J, Oenema, O, Bannink, A 2011. Dietary strategies to reducing N excretion from cattle: implications for methane emissions. Current Opinion in Environmental Sustainability 3, 414–422.
Ellis, JL, Bannink, A, France, J, Kebreab, E, Dijkstra, J 2010. Evaluation of enteric methane prediction equations for dairy cows used in whole farm models. Global Change Biology 16, 3246–3256.
Fels-Klerx, HJ, van der Olesen, JE, Madsen, MS, Uiterwijk, M, Goedhart, PW 2012. Climate change increases deoxynivalenol of wheat in north-western Europe. Food Additives and Contaminants 29, 1593–1604.
Fiala, N 2008. Meeting the demand: an estimation of potential future greenhouse gas emissions from meat production. Ecological Economics 67, 412–419.
Firestone, MK, Davidson, EA 1989. Microbiological basis of NO and N2O production and consumption in soil. In Exchange of trace gases between terrestrial ecosystems and the atmosphere (ed. MO Andreae and DS Schimel), pp. 7–21. John Wiley & Sons, Chichester, UK.
Foley, PA, Crosson, P, Lovett, DK, Boland, TM, O'Mara, FP, Kenny, DA 2011. Whole-farm systems modelling of greenhouse gas emissions from pastoral suckler beef cow production systems. Agriculture Ecosystems and Environment 142, 222–230.
Franks, JR, Hadingham, B 2012. Reducing greenhouse gas emissions from agriculture: avoiding trivial solutions to a global problem. Land Use Policy 29, 727–736.
Freer, M, Moore, AD, Donnelly, JR 2012. The GRAZPLAN animal biology model for sheep and cattle and the GrazFeed decision support tool. CSIRO Plant Industry Technical Paper, GPO Box 1600, Canberra, ACT 2601, Australia. Retrieved March 1, 2013, from http://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&ved=0CHoQFjAH&url=http%3A%2F%2Fwww.csiro.au%2F~%2FMedia%2FCSIROau%2FDivisions%2FCSIRO%2520Plant%2520Industry%2FGrazplan%2FTechPaperMay12-Word.docx&ei=t7kwUZ2ZKo6yhAff64DACQ&usg=AFQjCNHuNrv4NHXVT70CkyePkFXR-8Ox9g&sig2=jxNbCyex_JTgwpl5gKKFkw&bvm=bv.43148975,d.ZG4
Freibauer, A, Rounsevell, MDA, Smith, P, Verhagen, J 2004. Carbon sequestration in the agricultural soils of Europe. Geoderma 122, 1–23.
Gibbons, JM, Ramsden, SJ, Blake, A 2006. Modelling uncertainty in greenhouse gas emissions from UK agriculture at the farm level. Agriculture, Ecosystems and Environment 112, 347–355.
Giger-Reverdin, S, Morand-Fehr, P, Tran, G 2003. Literature survey of the influence of dietary fat composition on methane production in dairy cattle. Livestock Production Science 82, 73–79.
Graux, AI, Gaurut, M, Agabriel, J, Baumont, R, Delagarde, R, Delaby, L, Soussana, JF 2011. Development of the pasture simulation model for assessing livestock production under climate change. Agriculture, Agriculture, Ecosystems and Environment 144, 69–91.
Graux, AI, Lardy, R, Bellocchi, G, Soussana, JF 2012. Global warming potential of French grassland-based dairy livestock systems under climate change. Regional Environmental Change 12, 751–763.
Hammer, GL, Van Oosterom, E, McLean, G, Chapman, SC, Broad, I, Harland, P, Muchow, RC 2010. Adapting APSIM to model the physiology and genetics of complex adaptive traits in field crops. Journal of Experimental Botany 61, 2185–2202.
Hensen, A, Groot, TT, van den Bulk, WCM, Vermeulen, AT, Olesen, JE, Schelde, K 2006. Dairy farm CH4 and N2O emissions, from one square meter to the full farm scale. Agriculture, Ecosystems and Environment 112, 146–152.
Hindrichsen, IK, Wettstein, HR, Machmuller, A, Kreuzer, M 2006. Methane emission, nutrient degradation and nitrogen turnover in dairy cows and their slurry at different milk production scenarios with and without concentrate supplementation. Agriculture, Ecosystems and Environment 113, 150–161.
Hutchings, NJ, Sommer, SG, Jarvis, SG 1996. A model of ammonia volatilization from a grazing livestock farm. Atmospheric Environment 30, 589–599.
Hutchings, NJ, Olesen, JE, Petersen, BM, Berntsen, J 2007. Modelling spatial heterogeneity in grazed grassland and its effects on nitrogen cycling and greenhouse gas emissions. Agriculture, Ecosystems and Environment 121, 153–163.
Intergovernmental Panel on Climate Change (IPCC) 2006. IPCC guidelines for national greenhouse gas inventories. IPCC/IGES, Kanagawa, Japan.
Jeppesen, E, Kronvang, B, Olesen, JE, Audet, J, Søndergaard, M, Hoffmann, CC, Andersen, HE, Lauridsen, TL, Liboriussen, L, Larsen, SE 2011. Climate change effects on nitrogen loading from cultivated catchments in Europe: implications for nitrogen retention, ecological state of lakes and adaptation. Hydrobiologia 663, 1–21.
Keating, BA, Carberry, PS, Hammer, GL, Probert, ME, Robertson, MJ, Holzworth, D, Huth, NI, Hargreaves, JNG, Meinke, H, Hochman, Z, McLean, G, Verburg, K, Snow, V, Dimes, JP, Silburn, M, Wang, E, Brown, S, Bristow, KL, Asseng, S, Chapman, S, McCown, RL, Freebairn, DM, Smith, CJ 2003. An overview of APSIM, a model designed for farming systems simulation. European Journal of Agronomy 18, 267–288.
Kebreab, E, France, J, Beever, DE, Castillo, AR 2001. Nitrogen pollution by dairy cows and its mitigation by dietary manipulation. Nutrient Cycling in Agroecosystems 60, 275–285.
Kingston-Smith, AH, Davies, TE, Edwards, JE, Theodorou, MK 2008. From plants to animals; the role of plant cell death in ruminant herbivores. Journal of Experimental Botany 59, 521–532.
Lal, R 2008. Carbon sequestration. Philosophical Transactions of the Royal Society 363, 815–830.
Li, C, Salas, W, Zhang, R, Krauter, C, Rotz, A, Mitloehner, F 2012. Manure-DNDC: a biogeochemical process model for quantifying greenhouse gas and ammonia emissions from livestock manure systems. Nutrient Cycling in Agroecosystems 93, 163–200.
Linn, DM, Doran, JW 1984. Effect of water-filled pore space on carbon dioxide and nitrous oxide production in tilled and nontilled soils. Soil Science Society of America Journal 48, 1267–1272.
Lovett, DK, Shalloo, L, Dillon, P, O'Mara, FP 2006. A systems approach to quantify greenhouse gas fluxes from pastoral dairy production as affected by management regime. Agricultural Systems 88, 156–179.
Lovett, DK, Shalloo, L, Dillon, P, O'Mara, FP 2008. Greenhouse gas emissions from pastoral based dairying systems: the effect of uncertainty and management change under two contrasting production systems. Livestock Science 116, 260–274.
Matthews, RA, Chadwick, DR, Retter, AL, Blackwell, MSA, Yamulki, S 2010. Nitrous oxide emissions from small-scale farmland features of UK livestock farming systems. Agriculture, Ecosystems and Environment 136, 192–198.
McGechan, MB 1990. A review of losses arising during conservation of grass forage: part 2, storage losses. Journal of Agricultural Engineering Research 45, 1–30.
MEA 2005. Millennium ecosystem assessment. Ecosystems and human well-being. Biodiversity synthesis. World Resources Institute, Washington DC.
Mills, JAN, Crompton, LA, Reynolds, CK 2008. Ruminant nutrition regimes to reduce methane and nitrogen emissions. A meta-analysis of current databases. A Project Funded by the Milk Development Council (MDC/07/04/A). Retrieved October 5, 2012, from http://www.dairyco.org.uk/non_umbraco/download.aspx?media=5903.
Mills, JAN, Dijkstra, J, Bannink, A, Cammell, SB, Kebreab, E, France, J 2001. A mechanistic model of whole-tract digestion and methanogenesis in the lactating dairy cow: model development, evaluation, and application. Journal of Animal Science 79, 1584–1597.
Mills, JAN, Kebreab, E, Yates, CM, Crompton, LA, Cammell, SB, Dhanoa, MS, Agnew, RE, France, J 2003. Alternative approaches to predicting methane emissions from dairy cows. Journal of Animal Science 81, 3141–3150.
O'Brien, D, Shalloo, L, Grainger, C, Buckley, F, Horan, B, Wallace, M 2010. The influence of strain of Holstein-Friesian cow and feeding system on greenhouse gas emissions from pastoral dairy farms. Journal of Dairy Science 93, 3390–3402.
O'Brien, D, Shalloo, L, Buckley, F, Horan, B, Grainger, C, Wallace, M 2011. The effect of methodology on estimates of greenhouse gas emissions from grass-based dairy systems. Agriculture, Ecosystems and Environment 141, 39–48.
O'Brien, D, Shalloo, L, Patton, J, Buckley, F, Grainger, C, Wallace, M 2012a. A life cycle assessment of seasonal grass-based and confinement dairy farms. Agricultural Systems 107, 33–46.
O'Brien, D, Shalloo, L, Patton, J, Buckley, F, Grainger, C, Wallace, M 2012b. Evaluation of the effect of accounting method, IPCC v. LCA, on grass-based and confinement dairy systems’ greenhouse gas emissions. Animal 6, 1512–1527.
Olesen, JE, Schelde, K, Weiske, A, Weisbjerg, MR, Asman, WAH, Djurhuus, J 2006. Modelling greenhouse gas emissions from European conventional and organic dairy farms. Agriculture Ecosystems and Environment 112, 207–220.
Pan, G, Smith, P, Pan, W 2009. The role of soil organic matter in maintaining the productivity and yield stability of cereals in China. Agriculture Ecosystems and Environment 129, 344–348.
Payraudeau, S, van der Werf, HMG, Vertès, F 2007. Analysis of the uncertainty associated with the estimation of nitrogen losses from farming systems. Agricultural Systems 94, 416–430.
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, 380–389.
Petersen, SO, Blanchard, M, Chadwick, D, Del Prado, A, Edouard, N, Mosquera-Losada, J, Sommer, SG 2013. Manure management for GHG mitigation. Animal 7 (suppl. 2), 266–282.
Pilgrim, ES, Macleod, CJA, Blackwell, MSA, Bol, R, Hogan, DV, Chadwick, DR, Cardenas, L, Misselbrook, TH, Haygarth, PM, Brazier, RE, Hobbs, P, Hodgson, C, Jarvis, SC, Dungait, J, Murray, P, Firbank, L 2010. Interactions among agricultural production and other ecosystem services delivered from European temperate grassland systems. Advances in Agronomy 109, 117.
Rees, RM, Bingham, IJ, Baddeley, JA, Watson, CA 2005. The role of plants and land management in sequestering soil carbon in temperate arable and grassland ecosytems. Geoderma 128, 130–154.
Rotz, C, Oenema, J, Keulen, H 2006. Whole farm management to reduce nutrient losses from dairy farms: a simulation study. Applied Engineering in Agriculture 22, 773–784.
Rotz, CA, Montes, F, Chianese, DS 2010. The carbon footprint of dairy production systems through partial life cycle assessment. Journal of Dairy Science 93, 1266–1282.
Rotz, CA, Soder, KJ, Skinner, R, Dell, C, Kleinman, P, Schmidt, J, Bryant, R 2009. Grazing can reduce the environmental impact of dairy production systems. Forage and Grazing Lands. Retrieved October 15, 2012, from http://www.plantmanagementnetwork.org/pub/fg/research/2009/impact/ Rotz, CA, Corson, MS, Chianese, DS, Montes, F, Hafner, SD, Jarvis, R, Coiner, CU 2012. Integrated Farm System Model: Reference Manual. USDA Agricultural Research Service. Retrieved October 15, 2012 from http://www.ars.usda.gov/Main/docs.htm?docid=21345
Ruser, R, Flessa, H, Russow, R, Schmidt, G, Buegger, F, Munch, JC 2006. Emission of N2O, N2 and CO2 from soil fertilized with nitrate: effect of compaction, soil moisture and rewetting. Soil Biology and Biochemistry 38, 263–274.
Schils, RLM, Olesen, JE, Del Prado, A, Soussana, JF 2007b. A review of farm level modelling approaches for mitigating greenhouse gas emissions from ruminant livestock systems. Livestock Science 112, 240–251.
Schils, RLM, Verhagen, A, Aarts, HFM, Kuikman, PJ, ŠEbek, LBJ 2006. Effect of improved nitrogen management on greenhouse gas emissions from intensive dairy systems in the Netherlands. Global Change Biology 12, 382–391.
Schils, RLM, de Haan, MHA, Hemmer, JGA, van den Pol-van Dasselaar, A, de Boer, JA, Evers, AG, Holshof, G, van Middelkoop, JC, Zom, RLG 2007a. DairyWise, a whole-farm dairy model. Journal of Dairy Science 90, 5334–5346.
Shalloo, L, Dillon, P, Rath, M, Wallace, M 2004. Description and validation of the Moorepark dairy system model. Journal of Dairy Science 87, 1945–1959.
Smith, P, Olesen, JE 2010. Synergies between the mitigation of, and adaptation to, climate change in agriculture. Journal of Agricultural Science 148, 543–552.
Stackhouse-Lawson, KR, Rotz, CA, Oltjen, JW, Mitloehner, FM 2012. Carbon footprint and ammonia emissions of California beef production systems. Journal of Animal Science 90, 4641–4655.
Steinfeld, H, Gerber, P, Wassenaar, T, Castel, V, De Haan, C 2006. Livestock's long shadow: environmental issues and options. FAO, Rome, Italy.
Thomassen, MA, van Calker, KJ, Smits, MCJ, Iepema, GL, de Boer, IJM 2008. Life cycle assessment of conventional and organic milk production in the Netherlands. Agricultural Systems 96, 95–107.
Thornton, PK 2010. Livestock production: recent trends, future prospects. Philosophical Transactions of the Royal Society B: Biological Sciences 365, 2853–2867.
Tol, RSJ 2005. Adaptation and mitigation: trade-offs in substance and methods. Environmental Science and Policy 8, 572–578.
Van Wijk, MT, Rufino, MC, Enahoro, D, Parsons, D, Silvestri, S, Valdivia, RO, Herrero, M 2012. A review on ffarm household modelling with a focus on climate change adaptation and mitigation. Working Paper No. XX, Copenhagen. Retrieved October 2, 2012, from http://ccafs.cgiar.org/sites/default/files/assets/docs/ilri_household_modelling_review_final.pdf
Vellinga, T, Hoving, I 2011. Maize silage for dairy cows: mitigation of methane emissions can be offset by land use change. Nutrient Cycling in Agroecosystems 89, 413–426.
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, 41–50.
Weightman, RM, Cottrill, BR, Wiltshire, JJJ, Kindred, DR, Sylvester-Bradley, R 2011. Opportunities for avoidance of land-use change through substitution of soybean meal and cereals in European livestock diets with bioethanol coproducts. Global Change Biology Bioenergy 3, 158–170.
Weiske, A, Vabitsch, A, Olesen, JE, Schelde, K, Michel, J, Friedrich, R, Kaltschmitt, M 2006. Mitigation of greenhouse gas emissions in European conventional and organic dairy farming. Agriculture Ecosystems and Environment 112, 221–232.
Weiss, F, Leip, A 2012. Greenhouse gas emissions from the EU livestock sector: a life cycle assessment carried out with the CAPRI model. Agriculture, Ecosystems and Environment 149, 124–134.
White, TA, Snow, VO 2012. A modelling analysis to identify plant traits for enhanced water-use efficiency of pasture. Crop and Pasture Science 63, 63–76.
Wreford, A, Moran, D, Adger, N 2010. Climate change and agriculture: impacts, adaptation and mitigation. OECD Publishing, Paris, France.
Zehetmeier, M, Baudracco, J, Hoffmann, H, Heissenhuber, A 2012. Does increasing milk yield per cow reduce greenhouse gas emissions? A system approach. Animal 6, 154–166.