Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Evaluation of greenhouse gas emissions from hog manure application in a Canadian cow–calf production system using whole-farm models

Aklilu W. Alemu A D , Kim H. Ominski A , Mario Tenuta B , Brian D. Amiro B and Ermias Kebreab C
+ Author Affiliations
- Author Affiliations

A Department of Animal Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

B Department of Soil Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

C Department of Animal Science, University of California, Davis, CA, 95616, USA.

D Corresponding author. Email: akliluwake@yahoo.com

Animal Production Science 56(10) 1722-1737 https://doi.org/10.1071/AN14994
Submitted: 8 December 2014  Accepted: 24 February 2015   Published: 27 April 2015

Abstract

The development of beneficial management practices is a key strategy to reduce greenhouse gas (GHG) emissions from animal agriculture. The objective of the present study was to evaluate the impact of time and amount of hog manure application on farm productivity and GHG emissions from a cow–calf production system using two whole-farm models. Detailed model inputs (climate, soil and manure properties, farm operation data) were collected from a 3-year field study that evaluated the following three treatments: no application of hog manure on grassland (baseline); a single application of hog manure on grassland in spring (single); and two applications of hog manure as fall and spring (split). All three treatments were simulated in a representative cow–calf production system at the farm-gate using the following whole-farm models: a Coupled Components Model (CCM) that used existing farm component models and the Integrated Farm System Model (IFSM). Annual GHG intensities for the baseline scenario were 17.7 kg CO2-eq/kg liveweight for CCM and 18.1 kg CO2-eq/kg liveweight for IFSM. Of the total farm GHG emissions, 73–77% were from enteric methane production. The application of hog manure on grassland showed a mean emission increase of 7.8 and 8.4 kg CO2-eq/kg liveweight above the baseline for the single and split scenarios, respectively. For the manured scenarios, farm GHG emissions were mainly from enteric methane (47–54%) and soil nitrous oxide (33–41%). Emission estimates from the different GHG sources in the farm varied between models for the single and split application scenarios. Although farm productivity was 3–4% higher in the split than in single application (0.14 t liveweight/ha), the environmental advantage of applying manure in a single or split application was not consistent between models for farm emission intensity. Further component and whole-farm assessments are required to fully understand the impact of timing and the amount of livestock manure application on GHG emissions from beef production systems.

Additional keywords: beef cattle, emissions intensity, single application, split application.


References

Abdalla M, Jones M, Yeluripati J, Smith P, Burke J, Williams M (2010) Testing DayCent and DNDC model simulations of N2O fluxes and assessing the impacts of climate change on the gas flux and biomass production from a humid pasture. Atmospheric Environment 44, 2961–2970.
Testing DayCent and DNDC model simulations of N2O fluxes and assessing the impacts of climate change on the gas flux and biomass production from a humid pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXotlSltbk%3D&md5=5aeac12b1f3e24134de3caf94772f010CAS |

Adams BW, Richman J, Poulin-Klein L, France K, Moisey D, McNeil RL (2013) ‘Rangeland plant communities and range health assessment guidelines for the mixed grass natural subregion of Alberta. Second approximation. Lethbridge, Pub. No. T/03940.’ (Rangeland Management Branch, Policy Division, Alberta Environment and Sustainable Resource Development: Lethbridge, AB, Canada )

Adom F, Maes A, Workman C, Clayton-Nierderman Z, Thoma G, Shonnard D (2012) Regional carbon footprint analysis of dairy feeds for milk production in the USA. The International Journal of Life Cycle Assessment 17, 520–534.
Regional carbon footprint analysis of dairy feeds for milk production in the USA.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XmslWlsbc%3D&md5=3b566140a92ec26427ca0a712171afa9CAS |

Agriculture and Agri-Food Canada (2011) Sustainable management on nutrients on the landscape for in-field livestock winter feeding system. Available at http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1294669298001&lang=eng [Verified 15 May 2012]

Alberta Agriculture, Food and Rural Development (2003) ‘CowBytes©, beef cattle ration balancer (V. 4. 6. 8).’ (Agriculture and Rural Development: Alberta, Canada)

Alemu AW, Ominski KH, Kebreab E (2011) Estimation of enteric methane emissions trends (1990–2008) from Manitoba beef cattle using empirical and mechanistic models. Canadian Journal of Animal Science 91, 305–321.
Estimation of enteric methane emissions trends (1990–2008) from Manitoba beef cattle using empirical and mechanistic models.Crossref | GoogleScholarGoogle Scholar |

Allen A, Jarvis S, Headon D (1996) Nitrous oxide emissions from soils due to inputs of nitrogen from excreta return by livestock on grazed grassland in the UK. Soil Biology & Biochemistry 28, 597–607.
Nitrous oxide emissions from soils due to inputs of nitrogen from excreta return by livestock on grazed grassland in the UK.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XjvF2itrY%3D&md5=28ee782013e1d7e255ff0da234018279CAS |

Bannink A, Kogut J, Dijkstra J, France J, Kebreab E, Van Vuuren AM, Tamminga S (2006) Estimation of the stoichiometry of volatile fatty acid production in the rumen of lactating cows. Journal of Theoretical Biology 238, 36–51.
Estimation of the stoichiometry of volatile fatty acid production in the rumen of lactating cows.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXht1Oms7jN&md5=7f4767a698d586c410f44b7d039c6c79CAS | 16111711PubMed |

Basarab JA, Okine EK, Baron VS, Marx T, Ramsey P, Ziegler K, Lyle K (2005) Methane emissions from enteric fermentation in Alberta’s beef cattle population. Canadian Journal of Animal Science 85, 501–512.
Methane emissions from enteric fermentation in Alberta’s beef cattle population.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xot1GqsbY%3D&md5=7869f5c605cbae23d7613041aca54a93CAS |

Basarab J, Baron V, López-Campos Ó, Aalhus J, Haugen-Kozyra K, Okine E (2012) Greenhouse gas emissions from calf- and yearling-fed beef production systems, with and without the use of growth promotants. Animals 2, 195–220.
Greenhouse gas emissions from calf- and yearling-fed beef production systems, with and without the use of growth promotants.Crossref | GoogleScholarGoogle Scholar |

Beauchemin KA, McAllister TA, McGinn SM (2009) Dietary mitigation of enteric methane from cattle. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 4, 18–27.
Dietary mitigation of enteric methane from cattle.Crossref | GoogleScholarGoogle Scholar |

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.
Life cycle assessment of greenhouse gas emissions from beef production in Western Canada: a case study.Crossref | GoogleScholarGoogle Scholar |

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 166–167, 663–677.
Mitigation of greenhouse gas emissions from beef production in western Canada: evaluation using farm-based life cycle assessment.Crossref | GoogleScholarGoogle Scholar |

Beaulieu MS (2004) ‘Manure management in Canada. Catalogue no. 21-021-MIE-No. 002.’ (Statistics Canada, Farm Environmental Management in Canada, Agricultural Division: Ottawa, Canada) Available at http://publications.gc.ca/collections/Collection/Statcan/21-021-M/21-021-MIE2004001.pdf [Verified 3 March 2012]

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.
The effect of future climate scenarios on the balance between productivity and greenhouse gas emissions from sheep grazing systems.Crossref | GoogleScholarGoogle Scholar |

Bernier JN, Undi M, Plaizier JC, Wittenberg KM, Donohoe GR, Ominski KH (2012) Impact of prolonged cold exposure on dry matter intake and enteric methane emissions of beef cows overwintered on low-quality forage diets with and without supplemented wheat and corn dried distillers grain with solubles (DDGS). Canadian Journal of Animal Science 92, 493–500.
Impact of prolonged cold exposure on dry matter intake and enteric methane emissions of beef cows overwintered on low-quality forage diets with and without supplemented wheat and corn dried distillers grain with solubles (DDGS).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtV2ntbk%3D&md5=6524092591824a4deabe990b3488e122CAS |

Bork EW, Blonski LJ (2012) Short-term native grassland compositional responses following liquid hog manure application. Canadian Journal of Plant Science 92, 55–65.
Short-term native grassland compositional responses following liquid hog manure application.Crossref | GoogleScholarGoogle Scholar |

Bouwman AF, Stebfest E, van Kessel C (2010) Nitrous oxide emissions from the nitrogen cycle in arable agriculture. In ‘Nitrous oxide and climate change’. (Ed. K Smith) pp. 85–106. (Earthscan LLC: Washington, DC)

Capper JL (2011) Replacing rose-tinted spectacles with a high-powered microscope: the historical vs. modern carbon footprint of animal agriculture. Animal Frontiers 1, 26–32.
Replacing rose-tinted spectacles with a high-powered microscope: the historical vs. modern carbon footprint of animal agriculture.Crossref | GoogleScholarGoogle Scholar |

Casey JW, Holden NM (2006a) Quantification of GHG emissions from sucker-beef production in Ireland. Agricultural Systems 90, 79–98.
Quantification of GHG emissions from sucker-beef production in Ireland.Crossref | GoogleScholarGoogle Scholar |

Casey JW, Holden NM (2006b) Greenhouse gas emissions from conventional, agri-environmental scheme, and organic Irish suckler-beef units. Journal of Environmental Quality 35, 231–239.
Greenhouse gas emissions from conventional, agri-environmental scheme, and organic Irish suckler-beef units.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtFGitr0%3D&md5=d862a8760351bda535d422574f12926bCAS | 16397099PubMed |

Chadwick DR (1997) Nitrous oxide and ammonia emission from grassland following applications of slurry: potential abatement practices. In ‘Gaseous nitrogen emission from grassland’. (Eds SC Jarvis, BF Pain) pp. 257–264. (CAB International: Wallingford, UK)

Chadwick D, Pain B, Brookman S (2000) Nitrous oxide and methane emissions following application of animal manures to grassland. Journal of Environmental Quality 29, 277–287.
Nitrous oxide and methane emissions following application of animal manures to grassland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXot1eisQ%3D%3D&md5=e634bc289eeee746ff84b6ffec132c89CAS |

Chianese DS, Rotz CA, Richard TL (2009a) Simulation of nitrous oxide emissions from dairy farms to assess greenhouse gas reduction strategies. Transactions of the ASABE 52, 1325–1335.
Simulation of nitrous oxide emissions from dairy farms to assess greenhouse gas reduction strategies.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXht1Wru7bK&md5=5078acb222e8b6ac29072c47ce01f893CAS |

Chianese DS, Rotz CA, Richard TL (2009b) Simulation of carbon dioxide emissions from dairy farms to assess greenhouse gas reduction strategies. Transactions of the ASABE 52, 1301–1312.
Simulation of carbon dioxide emissions from dairy farms to assess greenhouse gas reduction strategies.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXht1Wru7bO&md5=62e37be6c06ba9096c6f98df9cd0130aCAS |

Coppi L (2012) Nitrogen and phosphorus in soil and groundwater following repeated nitrogen-based swine slurry applications to a tame grassland on coarse textured soil. PhD Thesis, University of Manitoba, Canada. Available at http://mspace.lib.umanitoba.ca/handle/1993/14417. [Verified 13 September 2014]

Crosson P, Shalloo L, O’Brien D, Lanigan GL, 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 | GoogleScholarGoogle Scholar |

Del Grosso SJ, Parton WJ, Mosier AR, Walsh MK, Ojima DS, Thornton PE (2006) DAYCENT national-scale simulations of nitrous oxide emissions from cropped soils in the United States. Journal of Environmental Quality 35, 1451–1460.
DAYCENT national-scale simulations of nitrous oxide emissions from cropped soils in the United States.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xns1Cktbc%3D&md5=d70a40d5d02a4d6a0b965a5643180688CAS | 16825465PubMed |

Del Grosso SJ, Ojima DS, Parton WJ, Stehfest E, Heistemann M, DeAgelo B, Rose S (2009) Global scale DAYCENT model analysis of greenhouse gas emissions and mitigation strategies for cropped soils. Global and Planetary Change 67, 44–50.
Global scale DAYCENT model analysis of greenhouse gas emissions and mitigation strategies for cropped soils.Crossref | GoogleScholarGoogle Scholar |

Dijkstra J, Neal HD, Beever DE, France J (1992) Simulation of nutrient digestion, absorption and outflow in the rumen: model description. Journal of Nutrition 122, 2239–2256.
Simulation of nutrient digestion, absorption and outflow in the rumen: model description.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XmsFSnu7Y%3D&md5=64009eb3828389bc96c7dd862c416df3CAS | 1331382PubMed |

Dyer JA, Desjardins RL (2006) An integrated index of electrical energy use in Canadian agriculture with implications for greenhouse gas emissions. Biosystems Engineering 95, 449–460.
An integrated index of electrical energy use in Canadian agriculture with implications for greenhouse gas emissions.Crossref | GoogleScholarGoogle Scholar |

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

Ellis S, Yamulki S, Dixon E, Harrison R, Jarvis SC (1998) Denitrification and N2O emission from a UK pasture soil following the early spring application of cattle slurry and mineral fertilizer. Plant and Soil 202, 15–25.
Denitrification and N2O emission from a UK pasture soil following the early spring application of cattle slurry and mineral fertilizer.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXmt1Gjsb8%3D&md5=5bedb88b4dfc9a0f2f11313787bd018bCAS |

Environment Canada (2012) Precipitation product samples. Available at http://www.ec.gc.ca/natchem/default.asp?lang=En&n=B385159B-1. [Verified 11 April 2012]

Environment Canada (2014) National inventory report 1990–2012 (Parts 1, 2 and 3): greenhouse gas sources and sinks in Canada. The Canadian Government’s Submission to the UN Framework Convention on Climate Change. Greenhouse Gas Division. Environment Canada, Gatineau, QC. Available at http://www.ec.gc.ca/ges-ghg/ [Verified 5 September 2014]

Flessa H, Ruser R, Dörsch P, Kamp T, Jimenez MA, Munch JC, Beese F (2002) Integrated evaluation of greenhouse gas emissions (CO2, CH4, N2O) from two farming systems in southern Germany. Agriculture, Ecosystems & Environment 91, 175–189.
Integrated evaluation of greenhouse gas emissions (CO2, CH4, N2O) from two farming systems in southern Germany.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xms1KgsLc%3D&md5=eaa05bffc0e6bda76cb572e96e30e4f1CAS |

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 & Environment 142, 222–230.
Whole-farm systems modelling of greenhouse gas emissions from pastoral suckler beef cow production systems.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtValt7zE&md5=c605fc01f0c3a372cffa73683719a122CAS |

Gerber PJ, Steinfeld H, Henderson B, Mottet A, Opio C, Dijkman J, Falcucci A, Tempio G (2013) ‘Tackling climate change through livestock. A global assessment of emissions and mitigation opportunities.’ (Food and Agriculture Organization of the United Nations (FAO): Rome). Available at http://www.fao.org/docrep/018/i3437e/i3437e.pdf. [Verified 25 June 2014]

Hermansen JE, Kristensen T (2011) Management options to reduce the carbon footprint of livestock products. Animal Frontiers 1, 33–39.
Management options to reduce the carbon footprint of livestock products.Crossref | GoogleScholarGoogle Scholar |

Hünerberg M, Little SM, Beauchemin KA, McGinn SM, O’Connor D, Okine EK, Harstad OM, Kröbel R, McAllister TA (2014) Feeding high concentrations of corn dried distillers’ grains decreases methane, but increases nitrous oxide emissions from beef cattle production. Agricultural Systems 127, 19–27.
Feeding high concentrations of corn dried distillers’ grains decreases methane, but increases nitrous oxide emissions from beef cattle production.Crossref | GoogleScholarGoogle Scholar |

Intergovernmental Pannel on Climate Change (IPCC) (2006) Guidelines for national greenhouse gas inventories. In ‘Intergovernmental Panel on Climate Change’. (Eds S Eggleston, L Buendia, K Miwa, TK Ngara, H Tanabe) (Prepared by the National Greenhouse Gas Inventories Programme, IGES: Japan)

ISO (2006a) ‘Environmental management: life cycle assessment: principles and framework. (ISO 14040:2006).’ (European Committee for Standardization: Brussels)

ISO (2006b) ‘Environmental management: life cycle assessment: requirements and guidelines. (ISO 14044:2006).’ (European Committee for Standardization: Brussels)

Janzen HH, Angers DA, Boehm M, Bolinder M, Desjardins RL, Dyer JA, Ellert BH, Gibb DJ, Gregorich EG, Helgason BL, Lemke R, Massé D, McGinn SM, McAllister TA, Newlands N, Pattey E, Rochette P, Smith W, VandenBygaart AJ, Wang H (2006) A proposed approach to estimate and reduce net greenhouse gas emissions from whole farms. Canadian Journal of Soil Science 86, 401–418.
A proposed approach to estimate and reduce net greenhouse gas emissions from whole farms.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhvFKis74%3D&md5=27e018eff0b244008d95b9a968a11252CAS |

Johnson DE, Phetteplace HW, Seidl AF (2002) Methane, nitrous oxide and carbon dioxide emissions from ruminant livestock production systems. In ‘Greenhouse gases and animal agriculture’. (Eds J Takahashi, BA Young) pp. 77–86. (Elsevier: Amsterdam, The Netherlands)

Johnson DE, Phetteplace HW, Seidl AF, Schneider UA, McCarl BA (2003) Management variations for US beef production systems: effects on greenhouse gas emissions and profitability. In ‘The 3rd international methane and nitrous oxide mitigation conference’. pp. 953–961. (Coal Institute: Beijing, China) Available at http://www.coalinfo.net.cn/coalbed/meeting/2203/papers/agriculture/index.html [Verified 10 October 2014]

Jungnitsch PF, Schoenau JJ, Lardner HA, Jefferson PG (2011) Winter feeding beef cattle on the western Canadian prairies: Impacts on soil nitrogen and phosphorus cycling and forage growth. Agriculture, Ecosystems & Environment 141, 143–152.
Winter feeding beef cattle on the western Canadian prairies: Impacts on soil nitrogen and phosphorus cycling and forage growth.Crossref | GoogleScholarGoogle Scholar |

Kebreab E, Mills JAN, Crompton LA, Bannink A, Dijkstra J, Gerrits WJJ, France J (2004) An integrated mathematical model to evaluate nutrient partition in dairy cattle between animal and environment. Animal Feed Science and Technology 112, 131–154.
An integrated mathematical model to evaluate nutrient partition in dairy cattle between animal and environment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXmvFymtA%3D%3D&md5=4b0cf9e0080e3e95d6e167e5e6f77521CAS |

Kelln B, Lardner HA, McKinnon JJ, Campbell JR, Larson K, Damiran D (2011) Effect of winter feeding system on beef cow performance, reproductive efficiency, and system cost. The Professional Animal Scientist 27, 410–421.

Kelln B, Lardner H, Schoenau J, King T (2012) Effects of beef cow winter feeding systems, pen manure and compost on soil nitrogen and phosphorous amounts and distribution, soil density, and crop biomass. Nutrient Cycling in Agroecosystems 92, 183–194.
Effects of beef cow winter feeding systems, pen manure and compost on soil nitrogen and phosphorous amounts and distribution, soil density, and crop biomass.Crossref | GoogleScholarGoogle Scholar |

Kennedy PM, Milligan LP (1978) Effects of cold exposure on digestion, microbial synthesis and nitrogen transformation in sheep. British Journal of Nutrition 39, 105–117.
Effects of cold exposure on digestion, microbial synthesis and nitrogen transformation in sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1cXhtleqsbw%3D&md5=779424564ba7a94edc11979993409663CAS | 619963PubMed |

Knudsen MT, Yu-Hui Q, Yan L, Halberg N (2010) Environmental assessment of organic soybean (Glycine max) imported from China to Denmark: a case study. Journal of Cleaner Production 18, 1431–1439.
Environmental assessment of organic soybean (Glycine max) imported from China to Denmark: a case study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtVamtbjE&md5=52de6939cbea790ab78821e0c1d351b5CAS |

Li CS, Frolking S, Frolking TA (1992) A model of nitrous oxide evolution from soil driven by rainfall events: 1. model structure and sensitivity. Journal of Geophysical Research 97, 9759–9776.
A model of nitrous oxide evolution from soil driven by rainfall events: 1. model structure and sensitivity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXkt1GktQ%3D%3D&md5=c42d0c85bdebe5c55df41fcea67046d7CAS |

Li CS, Farahbakshazad N, Jaynes DB, Dinnes DL, Salas W, McLaughlin D (2006) Modeling nitrate leaching with a biogeochemical model modified based on observations in a row-crop field in Iowa. Ecological Modelling 196, 116–130.
Modeling nitrate leaching with a biogeochemical model modified based on observations in a row-crop field in Iowa.Crossref | GoogleScholarGoogle Scholar |

Li CS, 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.
Manure-DNDC: a biogeochemical process model for quantifying greenhouse gas and ammonia emissions from livestock manure systems.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XpvVyqtLc%3D&md5=13dfee4a347350122ee19ed0591807f1CAS |

Little S, Linderman J, Maclean K, Janzen H (2008) ‘Holos: a tool to estimate and reduce greenhouse gases from farms. Methodology and algorithms for versions 1.1.x.’ Cat. No. A52-136/2008E-PDF (Agriculture and Agri-Food Canada: Lethbridge, AB, Canada)

Ludington D, Johnson EL (2003) ‘Dairy farm energy audit summary.’ (FlexTech Services, New York State Energy Research and Development Authority, Albany, NY). Available at http://www.nyserda.ny.gov/Publications/Research-and-Development/~/media/Files/ Publications/Energy/Audit/Reports/dairy-farm-energy.ashx [Verified 2 December 2011]

Lupo CD, Clay DE, Benning JL, Stone JJ (2013) Life-cycle assessment of the beef cattle production system for the Northern Great Plains, USA. Journal of Environmental Quality 42, 1386–1394.
Life-cycle assessment of the beef cattle production system for the Northern Great Plains, USA.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhsVygt73K&md5=520fbd0844c66ccf956e7e3c1222a6f9CAS | 24216416PubMed |

MacNeil MD, Newman S, Enns RM, Stewart-Smith J (1994) Relative economic values for Canadian beef production using specialized sire and dam lines. Canadian Journal of Animal Science 74, 4ll–417.
Relative economic values for Canadian beef production using specialized sire and dam lines.Crossref | GoogleScholarGoogle Scholar |

Manitoba Agricultural Review (2001) Agriculture statistics. (Program and Policy Analysis Branch, Manitoba Agriculture and Food: Winnipeg, Canada) Available at http://digitalcollection.gov.mb.ca/awweb/pdfopener?smd=1&did=10622&md=1 [Verified 10 September 2012]

Manitoba Agriculture, Food and Rural Development (2013) ‘Guidelines for estimating beef backgrounding costs‘. Available at http://www.gov.mb.ca/agriculture/business-and-economics/financial-management/pubs/cop_beef_backgrounding.pdf [Verified 12 February 2014]

Manitoba Management Plus Program (MMPP) (2012) MMPP variety yield. Available at http://www.mmpp.com/mmpp.nsf/mmpp_index. html [Verified 11 November 2012]

McCartney D (2011) ‘Country pasture/forage resource profiles.’ (Agriculture and Agric.-Food Canada, Lacombe, Alberta). Available at http://www.fao.org/ag/AGP/AGPC/doc/Counprof/Canada/Canada.html [Verified 13 May 2012]

McCaughey WP, Wittenberg K, Corrigan D (1999) Impact of pasture type on methane production by lactating beef cows. Canadian Journal of Animal Science 79, 221–226.
Impact of pasture type on methane production by lactating beef cows.Crossref | GoogleScholarGoogle Scholar |

Mc Geough EJ, Little SM, Janzen HH, McAllister TA, McGinn SM, Beauchemin KA (2012) Life-cycle assessment of greenhouse gas emissions from dairy production in eastern Canada: a case study. Journal of Dairy Science 95, 5164–5175.
Life-cycle assessment of greenhouse gas emissions from dairy production in eastern Canada: a case study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xht1emsbnK&md5=cd2ad3b2792bd5087a7b79fed0532811CAS | 22916922PubMed |

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 F (2003) Alternative approaches to predicting methane emissions from dairy cows. Journal of Animal Science 81, 3141–3150.

Myhre G, Shindell D, Breon F-M, Collins W, Fuglestvedt J, Huang J, Koch D, Lamarque J-F, 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. 661–731. (Cambridge University Press: Cambridge, UK)

Nagy CN (2001) Energy and greenhouse gas emission coefficients for inputs used in agriculture. In ‘Report to prairie adaptation research collaborative (PARC)’. Centre for Studies in Agriculture, Law and the Environment, Saskatoon, Canada. Available at http://www.parc.ca/ [Verified 12 September 2014]

Narasimhalu P, Kong D, Choo TM (1998) Straw yields and nutrients of seventy-five Canadian barley cultivars. Canadian Journal of Animal Science 78, 127–134.
Straw yields and nutrients of seventy-five Canadian barley cultivars.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXjslSmsbs%3D&md5=8ac5f572181030de21167e919c2652ffCAS |

O’Mara FP (2011) The significance of livestock as a contributor to global greenhouse emissions today and in the near future. Animal Feed Science and Technology 166–167, 7–15.
The significance of livestock as a contributor to global greenhouse emissions today and in the near future.Crossref | GoogleScholarGoogle Scholar |

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.
Comparative life cycle environmental impacts of three beef production strategies in the upper midwestern United States.Crossref | GoogleScholarGoogle Scholar |

Petersen SO, Sommer SG, Béline F, Burton C, Dach J, Dourmad JY, Leip A, Misselbrook T, Nicholson F, Poulsen HD, Provolo G, Sørensen P, Vinnerås B, Weiske A, Bernal MP, Böhm R, Juhász C, Mihelic R (2007) Recycling of livestock manure in a whole-farm perspective. Livestock Science 112, 180–191.
Recycling of livestock manure in a whole-farm perspective.Crossref | GoogleScholarGoogle Scholar |

Phetteplace HW, Johnson DE, Seidl AF (2001) Greenhouse gas emissions from simulated beef and dairy livestock systems in the United States. Nutrient Cycling in Agroecosystems 60, 99–102.
Greenhouse gas emissions from simulated beef and dairy livestock systems in the United States.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xkt1Shsw%3D%3D&md5=09800a5ba24ad7e8661aeded37436101CAS |

Reijs J (2007) Improving slurry by diet adjustments. A novelty to reduce nitrogen losses from grassland based dairy farms. PhD Thesis, Wageningen University, Wageningen, The Netherlands.

Rochette P, van Bochove E, Prevost D, Angers DA, Cote D, Bertrand N (2000) Soil carbon and nitrogen dynamics following application of pig slurry for the 19th consecutive year: II. Nitrous oxide fluxes and mineral nitrogen. Soil Science Society of America Journal 64, 1396–1403.
Soil carbon and nitrogen dynamics following application of pig slurry for the 19th consecutive year: II. Nitrous oxide fluxes and mineral nitrogen.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmsF2iu7g%3D&md5=527b2333ddd149d8bcdaa8de2373c377CAS |

Rochette P, Angers DA, Chantigny MH, Bertrand N, Cote D (2004) Carbon dioxide and nitrous oxide emission following fall and spring applications of pig slurry to an agricultural soil. Soil Science Society of America Journal 68, 1410–1420.
Carbon dioxide and nitrous oxide emission following fall and spring applications of pig slurry to an agricultural soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXlvVKitrg%3D&md5=a4cb2136a306040d33c176129ec90a67CAS |

Rochette P, Guilmette D, Chantigny MH, Angers DA, MacDonald JD, Bertrand N, Parent L-É, Côte’ D, Gasser MO (2008) Ammonia volatilization following application of pig slurry increases with slurry interception by grass foliage. Canadian Journal of Soil Science 88, 585–593.
Ammonia volatilization following application of pig slurry increases with slurry interception by grass foliage.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtlaktr7F&md5=c9a9371f63d252474088501f18fd363dCAS |

Rodhe L, Pell M, Yamulki S (2006) Nitrous oxide, methane and ammonia emissions following slurry spreading on grassland. Soil Use and Management 22, 229–237.
Nitrous oxide, methane and ammonia emissions following slurry spreading on grassland.Crossref | GoogleScholarGoogle Scholar |

Rotz CA (2003) How to maintain forage quality during harvest and storage. In ‘Western Canadian Dairy Seminar 2003’. pp. 227–236. (Advanced Dairy Technology: Canada) Available at http://www.wcds.ca/proc/2003/ [Verified 12 August 2012]

Rotz CA, Buckmaster DR, Comerford JW (2005) A beef herd model for simulating feed intake, animal performance and manure excretion in farm systems. Journal of Animal Science 83, 231–242.

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.
The carbon footprint of dairy production systems through partial life cycle assessment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXitlOis7o%3D&md5=a40948a0d78b18ec6bcc26f08de758efCAS | 20172247PubMed |

Rotz CA, Corson MS, Chianese DS, Montes F, Hafner SD, Jarvis R, Coiner CU (2011a) ‘The integrated farm system model. Reference manual, Version 3.4.’ (Pasture Systems and Watershed Management Research Unit, Agricultural Research Service, USDA: PA, USA)

Rotz CA, Kleinman PJA, Dell CJ, Veith TL, Beegle DB (2011b) Environmental and economic comparisons of manure application methods in farming systems. Journal of Environmental Quality 40, 438–448.
Environmental and economic comparisons of manure application methods in farming systems.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXjsVWqtb0%3D&md5=a85ea5f92b83865f350b70e33903bb70CAS | 21520751PubMed |

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 |

Schils RLM, Olesen JE, del Prado A, Soussana JF (2007) A review of farm level modelling approaches for mitigating greenhouse gas emissions from ruminant livestock systems. Livestock Science 112, 240–251.
A review of farm level modelling approaches for mitigating greenhouse gas emissions from ruminant livestock systems.Crossref | GoogleScholarGoogle Scholar |

Shaffer MJ, Halvorson AD, Pierce FJ (1991) Nitrate leaching and economic analysis package (NLEAP): model description and application. In ‘Managing nitrogen for groundwater quality and farm profitability’. (Eds RF Follett, DR Deeney, RM Cruse) pp. 285–298. (Soil Science Society of America Journal: Madison, WI)

Sherlock RR, Sommer SG, Khan RZ, Wood CW, Guertal EA, Freney JR, Dawson CO, Cameron KC (2002) Ammonia, methane and nitrous oxide emission from pig slurry applied to a pasture in New Zealand. Journal of Environmental Quality 31, 1491–1501.
Ammonia, methane and nitrous oxide emission from pig slurry applied to a pasture in New Zealand.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XnsFems7s%3D&md5=9d7d17f2810fabffca79470aeac725b2CAS | 12371166PubMed |

Smith P, Martino D, Cai Z, Gwary D, Janzen H, Kumar P, McCarl B, Ogle S, O’Mara F, Rice C, Scholes B, Sirotenko O (2007) Agriculture. In ‘Climate change 2007: mitigation. Contribution of Working Group III to the fourth assessment report of the Intergovernmental Panel on Climate Change’. (Eds B Metz, OR Davidson, PR Bosch, R Dave, LA Meyer) pp. 499–540. (Cambridge University Press: Cambridge, UK)

Smith WN, Grant BB, Desjardins RL, Rochette P, Drury CF, Li C (2008) Evaluation of two process-based models to estimate soil N2O emissions in eastern Canada. Canadian Journal of Soil Science 88, 251–260.
Evaluation of two process-based models to estimate soil N2O emissions in eastern Canada.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmvV2lsbc%3D&md5=b8d7b9db7fbdef12904df5728f9a3625CAS |

Sommer SG, Petersen SO, Møller HB (2004) Algorithms for calculating methane and nitrous oxide emissions from manure management. Nutrient Cycling in Agroecosystems 69, 143–154.
Algorithms for calculating methane and nitrous oxide emissions from manure management.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXksVGmsrk%3D&md5=b77fae01f007d837f9662a472726a9a9CAS |

Takahashi T, Suzuki Y, Horiguchi K (2002) Effect of heat exposure on methane emission from expiratory gas in sheep fed with high concentrate diets. In ‘Proceeding of the 1st international conference on greenhouse gases and animal agriculture’. (Eds J Takahashi, BA Young, CR Soliva, M Kreuzer) pp. 7–11. (Elsevier: Obihiro, Japan)

Tenuta M, Mkhabela M, Tremorin D, Coppi L, Phipps G, Flaten D, Ominski K (2010) Nitrous oxide and methane emission from a coarse-texture grassland soil receiving hog slurry. Agriculture, Ecosystems & Environment 138, 35–43.
Nitrous oxide and methane emission from a coarse-texture grassland soil receiving hog slurry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXmslektbo%3D&md5=88c9d7fd84027660003ac3c05bc50818CAS |

Tremorin DA (2009) Greenhouse gas emissions from grassland pasture fertilized with liquid hog manure. MSc Thesis, University of Manitoba, Canada.

Tri-Provincial Manure Application and Use Guidelines (2006) Manitoba version. Prepared by Prairie Provinces Committee on Livestock Development and Manure Management Committee. Available at http://www.gov.mb.ca/agriculture/livestock/beef/pdf/baa08s01a.pdf [Verified 20 March 2014]

Velthof G, Kuikman P, Oenema O (2003) Nitrous oxide emission from animal manures applied to soil under controlled conditions. Biology and Fertility of Soils 37, 221–230.
Nitrous oxide emission from animal manures applied to soil under controlled conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXjtFKntrY%3D&md5=16a87498e5ffa8eebd4afea0c8b1ed36CAS |

Vergé XPC, Dyer JA, Desjardins RL, Worth D (2007) Greenhouse gas emissions from the Canadian dairy industry in 2001. Agricultural Systems 94, 683–693.
Greenhouse gas emissions from the Canadian dairy industry in 2001.Crossref | GoogleScholarGoogle Scholar |

Vergé XPC, Dyer JA, Desjardins RL, Worth D (2008) Greenhouse gas emissions from the Canadian beef industry. Agricultural Systems 98, 126–134.
Greenhouse gas emissions from the Canadian beef industry.Crossref | GoogleScholarGoogle Scholar |

Waldner CL, Kennedy RI, Rosengren L, Clark EG (2009) A field study of culling and mortality in beef cows from western Canada. The Canadian Veterinary Journal. La Revue Veterinaire Canadienne 50, 491–499.

Wang M (2007) ‘GREET version 1.8a.’ (Argonne National Laboratory) Available at http://www. transportation.anl.gov/publications/transforum/v8/v8n2/greet_18b.html. [Verified 10 June 2012]

White TA, Snow VO, King WMcG (2010) Intensification of New Zealand beef farming systems. Agricultural Systems 103, 21–35.
Intensification of New Zealand beef farming systems.Crossref | GoogleScholarGoogle Scholar |

Whitman T, Yanni SF, Whalen JK (2011) Life cycle assessment of corn stover production for cellulosic ethanol in Quebec. Canadian Journal of Soil Science 91, 997–1012.
Life cycle assessment of corn stover production for cellulosic ethanol in Quebec.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XislWiuro%3D&md5=998a2714fa7f8b04b43a33c027d6ebaaCAS |

Wiens MJ, Entz MH, Wilson C, Ominski KH (2008) Energy requirements for transport and surface application of liquid pig manure in Manitoba, Canada. Agricultural Systems 98, 74–81.
Energy requirements for transport and surface application of liquid pig manure in Manitoba, Canada.Crossref | GoogleScholarGoogle Scholar |

Wilson C, Undi M, Tenuta M, Wittenberg KM, Flaten D, Krause DO, Entz MH, Holley R, Ominski KH (2010) Pasture productivity, cattle productivity and metabolic status following fertilization of a grassland with liquid hog manure: a three-year study. Canadian Journal of Animal Science 90, 233–243.
Pasture productivity, cattle productivity and metabolic status following fertilization of a grassland with liquid hog manure: a three-year study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtVKisbjF&md5=e660e79986b187afb9280f8daf607576CAS |

Wilson C, Undi M, Tenuta M, Tremorin D, Coppi L, Flaten D, Wittenberg KM, Ominski KH (2011) Utilization of liquid hog manure to fertilize grasslands in southeast Manitoba: impact of application timing and forage harvest strategy on nutrient utilization and accumulation. Nutrient Cycling in Agroecosystems 91, 155–171.
Utilization of liquid hog manure to fertilize grasslands in southeast Manitoba: impact of application timing and forage harvest strategy on nutrient utilization and accumulation.Crossref | GoogleScholarGoogle Scholar |

Yamulki S, Jarvis SC, Owen P (1999) Methane emission and uptake from soils as influenced by excreta deposition from grazing animals. Journal of Environmental Quality 28, 676–682.
Methane emission and uptake from soils as influenced by excreta deposition from grazing animals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXhvFyrtLk%3D&md5=ce4fcb1c2b013c6b245c35024dcae561CAS |