Quantification and control of the greenhouse gas emissions from a dairy cow system Chun-Youl Baek a , Kun-Mo Lee b, * , Kyu-Hyun Park c a Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology, Japan b Department of Environmental Engineering, Eco-product Research Institute, Ajou University, Suwon, Republic of Korea c Kangwon National University, Agriculture and Life Sciences, Republic of Korea article info Article history: Received 9 August 2013 Received in revised form 27 January 2014 Accepted 4 February 2014 Available online 12 February 2014 Keywords: GHG emissions Gross energy LCA Dairy cow Feedstuff Uncertainty analysis abstract One of the major objectives of this research was to develop a tool that allows the control of greenhouse gas (GHG) emissions from a dairy cow system by considering variables such as feed composition, growth phase, enteric fermentation, and manure management. Of these, feed composition is the most influential and controllable variable. Therefore, any abatement measure applied for the reduction of GHG emissions from a dairy cow system must include the control of the feed composition. Thus, feedstuffs with lower GHG emission factors and gross energy values should be used. In addition, we developed a GHG emission quantification procedure for dairy cow systems based on a life cycle assessment (LCA) approach incorporating the IPCC’s GHG emission calculation equations, and set up a relationship between the feed composition and corresponding GHG emissions. Finally, a comparative assessment of the alternative feed compared to the original feed was performed to quantify the reduction of GHG emissions from the dairy cow system in order to select the most desirable feed composition. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Global greenhouse gas (GHG) emissions in 2050 are expected to increase by 50% compared with that in 2011 (Marchal et al., 2011). In particular, emissions of methane (CH 4 ) and nitrous oxide (N 2 O) from the livestock sector accounted for 14.5w18% of the global GHG emissions in 2005 (Steinfeld et al., 2006; Gerber et al., 2010). Nitrogen emission (a fraction of which becomes transformed into N 2 O, in both terrestrial and aquatic ecosystems) increased from 156 Tg N yr -1 1 in 1995 to 187 Tg N yr 1 in 2005, mainly because crop production increased by about 20% and meat production by 26% over the 10 years period (Smith et al., 2010). One of the major sources of GHG emissions from the livestock sector is the dairy cow production. Feed production and processing, and enteric fermen- tation from ruminants are reported as the two main sources of emissions, representing 45 and 39 percent of the sector emissions, respectively (Gerber et al., 2013). Most of GHG emissions from the dairy cow production is due to the feed, which is composed of different feedstuffs. Thus, proper control of the feed composition is essential to the abatement of GHG emission from the dairy cow production system. Life Cycle Assessment (LCA, ISO 14044, 2006) has been used widely by many researchers to assess the environmental impact of the dairy cow systems. (Haas et al., 2001; Cederberg and Mattsson, 2000; Ogino et al., 2004; Halberg et al., 2005; Thomassen et al., 2008). The research topics are diverse: they range from the iden- tification of the factors affecting the environmental impact for different types of farms (Haas et al., 2001; Halberg et al., 2005) to the comparative studies of the environmental impact of the key issues in the feedstuff production such as pesticide and fertilizer. (Cederberg and Mattsson, 2000). Recently, research on the quan- tification of GHG emissions from livestock increases substantially. In particular, GHG emissions from the enteric fermentation and manure treatment stages based on the tier 2 method of the IPCC became major research topics. (De Boer, 2003; Casey and Holden, 2006; Heller and Keoleian, 2011; Asselin-Balençon et al., 2012; Thoma et al., 2012). Most of these research works focused on comparison of the environmental impact based on different types of dairy cow farm. (Casey and Holden, 2006; Heller and Keoleian, 2011). Quantification of GHG emissions in these papers were based on two approaches. First is the use of local GHG emission factors in * Corresponding author. Tel.: þ82 31 219 2405. E-mail address: kunlee@ajou.ac.kr (K.-M. Lee). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2014.02.010 0959-6526/Ó 2014 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 70 (2014) 50e60