Greenhouse gas emissions from beef production systems in Denmark and Sweden

The purpose of the study was to define and describe typical beef production systems in Denmark and Sweden and estimate greenhouse gas (GHG) emissions including contribution from soil carbon changes and land use change (LUC) in a life cycle perspective (LCA). Five typical Danish (DK) and four typical Swedish (SE) systems were identified; hereof three systems with beef from beef breed cattle and six systems with beef from bull calves derived from dairy production system (including steers). The beef breed systems include an extensive system (DK) and two intensive systems (SE, DK). In the systems with beef from dairy bull calves, the bull calves were slaughtered at different ages; 9.0 months (SE), 9.4 months (DK), 11.5 months (DK), 19.0 months (SE) and at 25.0 months in the two systems with steers (DK, SE). Feed use and carbon footprint (CF) per kg meat were positively correlated. Beef from dairy bull calves slaughtered between 9.0 and 19.0 months had the lowest CF (8.9-11.5 kg CO2/kg carcass) and feed use (7.3-11.1 kg DM/kg carcass). The steer systems had a CF of 16.6-17.0 kg CO2/kg carcass and feed use of 13.2-15.5 kg DM/kg carcass. The highest CF and feed use were seen for beef breed systems at 23.1-29.7 kg CO2/kg carcass and 20.9-29.8 kg DM/kg carcass, respectively. The GHG contribution from LUC was positively correlated to the use of arable land. Beef from dairy bull calves had the lowest LUC contribution (13-1.6 kg CO2/kg carcass) from a land use of 9.4-11.5 m(2)/kg carcass. The highest LUC contribution (2.5-3.5 kg CO2/kg carcass) and land use of 17.3-24.7 m(2)/kg carcass was seen for beef from beef breed systems, the Swedish dairy bull calf slaughtered at 19 month, and the Danish steer. Besides arable land, the beef breed systems also used permanent pastures that were assumed not to contribute to LUC. Carbon (C) sequestration from crop residues and use of manure had a mitigating effect on GHG emission in all beef systems. The lowest C sequestration was seen for systems with beef from dairy bull calves slaughtered between 9 and 19 months, making up 0.2-0.9 kg CO2/kg carcass, and the highest C sequestration was for the steer production and the beef breed systems, contributing between 23 and 4.8 kg CO2/kg carcass. The present study supports the hypothesis that feed use per kg carcass weight is a main driver for variation in greenhouse gas emission, land use change and soil carbon changes for beef meat sourced from different beef production systems. For the carbon footprint per kg carcass there was a positive correlation with feed use and therefore also the lowest carbon footprint per kg carcass in systems with the lowest feed intake, such as bull calves from dairy production. (C) 2015 Elsevier B.V. All rights reserved.