How can grass-based dairy farmers reduce the carbon footprint of milk?
D. O’Brien A B , A. Geoghegan A , K. McNamara A and L. Shalloo A
+ Author Affiliations
- Author Affiliations
A Livestock Systems Research Department, AGRIC, Teagasc, Moorepark, Fermoy, County Cork, Ireland.
B Corresponding author. Email: donal.mobrien@teagasc.ie
Animal Production Science 56(3) 495-500 https://doi.org/10.1071/AN15490
Submitted: 27 August 2015 Accepted: 6 November 2015 Published: 9 February 2016
Abstract
The Irish dairy industry aims to increase milk production from grass-based farms following the removal of the EU milk-quota system, but is also required to minimise greenhouse gas (GHG) emissions to meet European reduction targets. Consequently, the sector is under increasing pressure to reduce GHG emissions per unit of milk, or carbon footprint (CF). Therefore, the goal of the present study was to determine the main sources of the CF of grass-based milk production and to identify mitigation strategies that can be applied to reduce farm footprints. In total, the CF of milk was estimated for 62 grass-based dairy farms in 2014. The method used to quantify GHG emissions was a life cycle assessment (LCA), independently certified to comply with the British standard for LCA (PAS 2050). The LCA method was applied to calculate annual on- and off-farm GHG emissions associated with dairy production until milk was sold from the farm in CO2-equivalent (CO2-eq). Annual GHG emissions computed using LCA were allocated to milk on the basis of the economic value of dairy products and expressed per kilogram of fat- and protein-corrected milk to estimate CF. Enteric methane was the main source of the CF of milk (46%), followed by emissions from inorganic N fertilisers (16%), manure (16%) and concentrate feedstuffs (8%). The mean CF of milk from the 62 farms was 1.26 kg of CO2-eq per kilogram of fat- and protein-corrected milk, but varied from 0.98 kg to 1.67 kg as measured using the 95% confidence interval. The CF of milk was correlated with numerous farm attributes, particularly N-fertiliser, the percentage of grazed grass in the diet, and production of milk solids. Grass-based dairy farmers can significantly improve these farm attributes by increasing herd genetic merit, extending the length of the grazing season and optimising N fertiliser use and, thereby, reduce the CF of milk.
Additional keywords: climate change, cow, mitigation, pasture.
References
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.| The effect of improving cow productivity, fertility, and longevity on the global warming potential of dairy systems.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXnvFahtr8%3D&md5=8fbab5230a1a8bcd671fe51b817d4c74CAS | 21700056PubMed |
Berry DP, Shalloo L, Cromie AR, Veerkamp RF, Dillon P, Am PR, Kearney JF, Evans RD, Wickham B (2007) The economic breeding index: a generation on. Technical report to the Irish Cattle Breeding Federation. Irish Cattle Breeding Federation, Shinagh house, Bandon, Co. Cork, Ireland. Available at http://www.icbf.com/publications/files/economic_breeding_index.pdf {Verified 19 June 2015]
Beukes PC, Gregorini P, Romera AJ, Levy G, Waghorn GC (2010) Improving production efficiency as a strategy to mitigate greenhouse gas emissions on pastoral dairy farms in New Zealand. Agriculture, Ecosystems & Environment 136, 358–365.
| Improving production efficiency as a strategy to mitigate greenhouse gas emissions on pastoral dairy farms in New Zealand.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXisFenurY%3D&md5=ce69dffbe2be8828da9ea26cbeb7ab56CAS |
BSI (2011) ‘PAS 2050:2011: specification for the assessment of life cycle greenhouse gas emissions of goods and services.’ (British Standards Institute: London)
Capper JL, Cady RA, Bauman DE (2009) The environmental impact of dairy production: 1944 compared with 2007. Journal of Animal Science 87, 2160–2167.
| The environmental impact of dairy production: 1944 compared with 2007.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXms1eis7o%3D&md5=3ce40cb76fa9623532ebe560a01ab185CAS | 19286817PubMed |
Carbon Trust (2013) ‘Carbon-footprinting software: footprint expert.’ (The Carbon Trust, Dorset House, Stamford Street: London.) Available at http://www.carbontrust.com/software [Verified 5 July 2015]
Christie KM, Rawnsley RP, Eckard RJ (2011) A whole farm systems analysis of greenhouse gas emissions of 60 Tasmanian dairy farms. Animal Feed Science and Technology 166–167, 653–662.
| A whole farm systems analysis of greenhouse gas emissions of 60 Tasmanian dairy farms.Crossref | GoogleScholarGoogle Scholar |
DairyCo (2012) ‘Greenhouse gas emissions on British dairy farms. DairyCo Carbon footprinting study: Year one.’ (Agriculture & Horticulture Development Board. Kenilworth, Warwickshire, UK)
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.
| Greenhouse gas mitigation in animal production: towards an integrated life cycle sustainability assessment.Crossref | GoogleScholarGoogle Scholar |
Duffy P, Hanley E, Hyde B, O’Brien P, Ponzi J, Cotter E, Black K (2014) Ireland national inventory report 2012. Greenhouse gas emissions 1990–2012 reported to the United Nations framework convention on climate change. Environmental Protection Agency, Johnstown Castle Estate, Co. Wexford, Ireland.
Hennessy T, Moran B (2015) ‘National farm survey 2014.’ (Teagasc Agricultural Economics and Farm Surveys Department: Athenry, Co. Galway, Ireland)
ICBF (2015) ‘Dairy herd plus.’ (Irish Cattle Breeding Federation: Shinagh, Bandon, Co. Cork, Ireland) Available at http://www.icbf.com/?page_id=149 [Verified 14 April 2015]
IDF (2010) ‘A common carbon footprint for dairy. The IDF guide to standard lifecycle assessment methodology for the dairy industry.’ Bulletin of the International Dairy Federation 445. (IDF: Brussels)
IPCC (2006) ‘2006 Intergovernmental Panel on Climate Change guidelines for national greenhouse inventories.’ Prepard by the national greenhouse gas inventories program. (Eds HS Eggleston, L Buendia, K Miwa, T Ngara, K Tanabe) (Institute for Global Environmental Strategies: Hayama, Japan)
Leip A, Weiss F, Wassenaar T, Perez I, Fellmann T, Loudjani P, Tubiello F, Grandgirard D, Monni S, Biala K (2010) Evaluation of the livestock’s sector contribution to the EU greenhouse gas emissions (GGELS). Final report. European Commission, Joint Research Center, Ispra, Italy.
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.
| Greenhouse gas emissions from pastoral based dairying systems: the effect of uncertainty and management change under two contrasting production systems.Crossref | GoogleScholarGoogle Scholar |
Martin C, Morgavi DP, Doreau M (2010) Methane mitigation in ruminants: from microbe to the farm scale. Animal 4, 351–365.
| Methane mitigation in ruminants: from microbe to the farm scale.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhslWgs7k%3D&md5=eb26a3959e2a2f59e9df73f746e4d771CAS | 22443940PubMed |
Myhre G, Shindell D, Bréon FM, Collins W, Fuglestvedt J, Huang J, Koch D, Lamarque JF, Lee D, Mendoza B, Nakajima T, Robock A, Stephens G, Takemura T, Zhang H (2013) Anthropogenic and natural radiative forcing. In ‘Climate change 2013: the physical science basis’. Contribution of Working Group I to the fifth assessment report of the Intergovernmental Panel on Climate Change. (Eds TF Stocker, D Qin, GK Plattner, M Tignor, SK Allen, J Boschung, A Nauels, Y Xia, V Bex, PM Midgley) pp. 712–716. (Cambridge University Press: Cambridge, UK)
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.
| The influence of strain of Holstein–Friesian cow and feeding system on greenhouse gas emissions from pastoral dairy farms.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtVOht77M&md5=6f9f6e956f0ef5823d2889d9876ec555CAS | 20630255PubMed |
O’Brien D, Brennan P, Humphreys J, Ruane E, Shalloo L (2014) An appraisal of carbon footprint of milk from commercial grass-based dairy farms in Ireland according to a certified life cycle assessment methodology. The International Journal of Life Cycle Assessment 19, 1469–1481.
| An appraisal of carbon footprint of milk from commercial grass-based dairy farms in Ireland according to a certified life cycle assessment methodology.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXhtVGru7rL&md5=38c72f1fe9293c2e187e7ec6786977acCAS |
O’Mara FP (2012) The role of grasslands in food security and climate change. Annals of Botany 110, 1263–1270.
| The role of grasslands in food security and climate change.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC38bptlClsQ%3D%3D&md5=80453162cd8ecb53e56ab0921752a395CAS | 23002270PubMed |
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 & Environment 112, 207–220.
| Modelling greenhouse gas emissions from European conventional and organic dairy farms.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xktl2lug%3D%3D&md5=9d518464c5f988e70e503923dee9d107CAS |
Opio C, Gerber P, Mottet A, Falcucci A, Tempio G, Macleod M, Vellinga T, Henderson B, Steinfeld H (2013) ‘Greenhouse gas emissions from ruminant supply chains: a global life cycle assessment.’ (Food and Agriculture Organization of the United Nations: Rome)
Ramsbottom G, Cromie AR, Horan B, Berry DP (2012) Relationship between dairy cow genetic merit and profit on commercial spring calving dairy farms. Animal 6, 1031–1039.
| Relationship between dairy cow genetic merit and profit on commercial spring calving dairy farms.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3s%2FitVGmsg%3D%3D&md5=2e05b914c0b26247ab76b55ce3f9f58aCAS | 23031462PubMed |
SAS (2008) ‘SAS user guide version 9.1.3.’ (Statistical Analysis Systems Institute: Cary, NC)
Schils RLM, Verhagen A, Aarts HFM, Šebek LBJ (2005) A farm level approach to define successful mitigation strategies for GHG emissions from ruminant livestock systems. Nutrient Cycling in Agroecosystems 71, 163–175.
| A farm level approach to define successful mitigation strategies for GHG emissions from ruminant livestock systems.Crossref | GoogleScholarGoogle Scholar |
Soussana JF, Tallec T, Blanfort V (2010) Mitigating the greenhouse gas balance of ruminant production systems through carbon sequestration in grasslands. Animal 4, 334–350.
| Mitigating the greenhouse gas balance of ruminant production systems through carbon sequestration in grasslands.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhslWgs70%3D&md5=dc07c51e8146da8bceb7f3e19e3b4039CAS | 22443939PubMed |
Thoma G, Popp J, Shonnard D, Nutter D, Matlock M, Ulrich R, Kellogg W, Kim DS, Neiderman Z, Kemper N, Adom F, East C (2013) Regional analysis of greenhouse gas emissions from USA dairy farms: a cradle to farm-gate assessment of the American dairy industry circa 2008. International Dairy Journal 31, S29–S40.
| Regional analysis of greenhouse gas emissions from USA dairy farms: a cradle to farm-gate assessment of the American dairy industry circa 2008.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhslSlsr3N&md5=0e7ea50e08e38033beb11b0232cffad7CAS |
Yan MJ, Humphreys J, Holden NM (2011) An evaluation of life cycle assessment of European milk production. Journal of Environmental Management 92, 372–379.
| An evaluation of life cycle assessment of European milk production.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhs1WktLfK&md5=633d9b9d31c62a7cbfc5d04c05c3b075CAS | 21055870PubMed |
Yan MJ, Humphreys J, Holden NM (2013) Life cycle assessment of milk production from commercial dairy farms: the influence of management tactics. Journal of Dairy Science 96, 4112–4124.
| Life cycle assessment of milk production from commercial dairy farms: the influence of management tactics.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXnt1altLw%3D&md5=84951092362f4751ca4e6db3612bd0d7CAS | 23660142PubMed |
Zehetmeier M, Hoffmann H, Sauer J, Hofmann G, Dorfner G, O’Brien D (2014) A dominance analysis of greenhouse gas emissions, beef output and land use of German dairy farms. Agricultural Systems 129, 55–67.
| A dominance analysis of greenhouse gas emissions, beef output and land use of German dairy farms.Crossref | GoogleScholarGoogle Scholar |
