Resource use and greenhouse gas emissions from grain-finishing beef cattle in seven Australian feedlots: a life cycle assessment

2017 ◽  
Vol 57 (6) ◽  
pp. 1149 ◽  
Author(s):  
Stephen Wiedemann ◽  
Rod Davis ◽  
Eugene McGahan ◽  
Caoilinn Murphy ◽  
Matthew Redding

Grain finishing of cattle has become increasingly common in Australia over the past 30 years. However, interest in the associated environmental impacts and resource use is increasing and requires detailed analysis. In this study we conducted a life cycle assessment (LCA) to investigate impacts of the grain-finishing stage for cattle in seven feedlots in eastern Australia, with a particular focus on the feedlot stage, including the impacts from producing the ration, feedlot operations, transport, and livestock emissions while cattle are in the feedlot (gate-to-gate). The functional unit was 1 kg of liveweight gain (LWG) for the feedlot stage and results are included for the full supply chain (cradle-to-gate), reported per kilogram of liveweight (LW) at the point of slaughter. Three classes of cattle produced for different markets were studied: short-fed domestic market (55–80 days on feed), mid-fed export (108–164 days on feed) and long-fed export (>300 days on feed). In the feedlot stage, mean fresh water consumption was found to vary from 171.9 to 672.6 L/kg LWG and mean stress-weighted water use ranged from 100.9 to 193.2 water stress index eq. L/kg LWG. Irrigation contributed 57–91% of total fresh water consumption with differences mainly related to the availability of irrigation water near the feedlot and the use of irrigated feed inputs in rations. Mean fossil energy demand ranged from 16.5 to 34.2 MJ lower heating values/kg LWG and arable land occupation from 18.7 to 40.5 m2/kg LWG in the feedlot stage. Mean greenhouse gas (GHG) emissions in the feedlot stage ranged from 4.6 to 9.5 kg CO2-e/kg LWG (excluding land use and direct land-use change emissions). Emissions were dominated by enteric methane and contributions from the production, transport and milling of feed inputs. Linear regression analysis showed that the feed conversion ratio was able to explain >86% of the variation in GHG intensity and energy demand. The feedlot stage contributed between 26% and 44% of total slaughter weight for the classes of cattle fed, whereas the contribution of this phase to resource use varied from 4% to 96% showing impacts from the finishing phase varied considerably, compared with the breeding and backgrounding. GHG emissions and total land occupation per kilogram of LWG during the grain finishing phase were lower than emissions from breeding and backgrounding, resulting in lower life-time emissions for grain-finished cattle compared with grass finishing.

2016 ◽  
Vol 56 (7) ◽  
pp. 1070 ◽  
Author(s):  
S. G. Wiedemann ◽  
M.-J. Yan ◽  
C. M. Murphy

This study conducted a life cycle assessment (LCA) investigating energy, land occupation, greenhouse gas (GHG) emissions, fresh water consumption and stress-weighted water use from production of export lamb in the major production regions of New South Wales, Victoria and South Australia. The study used data from regional datasets and case study farms, and applied new methods for assessing water use using detailed farm water balances and water stress weighting. Land occupation was assessed with reference to the proportion of arable and non-arable land and allocation of liveweight (LW) and greasy wool was handled using a protein mass method. Fossil fuel energy demand ranged from 2.5 to 7.0 MJ/kg LW, fresh water consumption from 58.1 to 238.9 L/kg LW, stress-weighted water use from 2.9 to 137.8 L H2O-e/kg LW and crop land occupation from 0.2 to 2.0 m2/kg LW. Fossil fuel energy demand was dominated by on-farm energy demand, and differed between regions and datasets in response to production intensity and the use of purchased inputs such as fertiliser. Regional fresh water consumption was dominated by irrigation water use and losses from farm water supply, with smaller contributions from livestock drinking water. GHG emissions ranged from 6.1 to 7.3 kg CO2-e/kg LW and additional removals or emissions from land use (due to cultivation and fertilisation) and direct land-use change (due to deforestation over previous 20 years) were found to be modest, contributing between –1.6 and 0.3 kg CO2-e/kg LW for different scenarios assessing soil carbon flux. Excluding land use and direct land-use change, enteric CH4 contributed 83–89% of emissions, suggesting that emissions intensity can be reduced by focussing on flock production efficiency. Resource use and emissions were similar for export lamb production in the major production states of Australia, and GHG emissions were similar to other major global lamb producers. The results show impacts from lamb production on competitive resources to be low, as lamb production systems predominantly utilised non-arable land unsuited to alternative food production systems that rely on crop production, and water from regions with low water stress.


2018 ◽  
Vol 58 (6) ◽  
pp. 1153 ◽  
Author(s):  
Stephen G. Wiedemann ◽  
Eugene J. McGahan ◽  
Caoilinn M. Murphy

Utilisation of water, energy and land resources is under pressure globally because of increased demand for food, fibre and fuel production. Australian pork production utilises these resources both directly to grow and process pigs, and indirectly via the consumption of feed and other inputs. With increasing demand and higher costs associated with these resources, supply chain efficiency is a growing priority for the industry. This study aimed to quantify fresh water consumption, stress-weighted water use, fossil fuel energy use and land occupation from six case study supply chains and the national herd using a life cycle assessment approach. Two functional units were used: 1 kg of pork liveweight (LW) at the farm-gate, and 1 kg of wholesale pork (chilled, bone-in). At the farm-gate, fresh water consumption from the case study supply chains ranged from 22.2 to 156.7 L/kg LW, with a national average value of 107.5 L/kg LW. Stress-weighted water use ranged from 6.6 to 167.5 L H2O-e /kg LW, with a national average value of 103.2 L H2O-e /kg LW. Fossil fuel energy demand ranged from 12.9 to 17.4 MJ/kg LW, with a national average value of 14.5 MJ/kg LW, and land occupation ranged from 10.9 to 16.1 m2/kg LW, with a national average value of 16.1 m2/kg LW and with arable land representing 97% to 99% of total land occupation. National average impacts associated with production of wholesale pork, including impacts from meat processing, were 184 ± 43 L fresh water consumption, 172 ± 53 L H2O-e stress-weighted water, 27 ± 2.6 MJ fossil fuel energy demand and 25.9 ± 5.5 m2 land/kg wholesale pork. Across all categories through to the wholesale product, resource use was highest from the production of feed inputs, indicating that improving feed conversion ratio is the most important production metric for reducing the resource use. Housing type and energy generation from manure management also influence resource use requirements and may offer improvement opportunities.


2016 ◽  
Vol 56 (9) ◽  
pp. 1418 ◽  
Author(s):  
S. G. Wiedemann ◽  
Eugene J. McGahan ◽  
Caoilinn M. Murphy

Agricultural industries are under increasing pressure to measure and reduce greenhouse gas emissions from the supply chain. The Australian pork industry has established proactive goals to improve greenhouse-gas (GHG) performance across the industry, but while productivity indicators are benchmarked by industry, similar data have not previously been collected to determine supply chain GHG emissions. To assess total GHG emissions from Australian pork production, the present study conducted a life-cycle assessment of six case study supply chains and the national herd for the year 2010. The study aimed to determine total GHG emissions and hotspots, and to determine the mitigation potential from alternative manure treatment systems. Two functional units were used: 1 kg of pork liveweight (LW) at the farm gate, and 1 kg of wholesale pork (chilled, bone-in) ready for packaging and distribution. Mean GHG emissions from the case study supply chains ranged from 2.1 to 4.5 kg CO2-e/kg LW (excluding land-use (LU) and direct land use-change (dLUC) emissions). Emissions were lowest from the piggeries that housed grower-finisher pigs on deep litter and highest from pigs housed in conventional systems with uncovered anaerobic effluent ponds. Mean contribution from methane from effluent treatment was 64% of total GHG at the conventional piggeries. Nitrous oxide arose from both grain production and manure management, comprising 7–33% of the total emissions. The GHG emissions for the national herd were 3.6 kg CO2-e/kg LW, with the largest determining factor on total emissions being the relative proportion of pigs managed with high or low emission manure management systems. Emissions from LU and dLUC sources ranged from 0.08 to 0.7 kg CO2-e/kg LW for the case study farms, with differences associated with the inclusion rate of imported soybean meal in the ration and feed-conversion ratio. GHG intensity (excluding LU, dLUC) from the national herd was 6.36 ± 1.03 kg CO2-e/kg wholesale pork, with the emission profile dominated by methane from manure management (50%), followed by feed production (27%) and then meat processing (8%). Inclusion of LU and dLUC emissions had a minor effect on the emission profile. Scenarios testing showed that biogas capture from anaerobic digestion with combined heat and power generation resulted in a 31–64% reduction in GHG emissions. Finishing pigs on deep litter as preferred to conventional housing resulted in 38% lower GHG emissions than conventional finishing.


2020 ◽  
Author(s):  
Benjamin Freeman ◽  
David Styles ◽  
Christopher Evans ◽  
David Chadwick ◽  
David Jones

<p>Global peatlands store >600 Gt of Carbon (C) but are highly vulnerable to degradation following drainage for agriculture. The extensively drained East Anglian Fens include half of England’s most productive agricultural land, produce ~33% of England’s vegetables and support a food production industry worth approximately £3 billion GBP.  However under arable management, these fen peat soils produce ~37.5 t CO<sub>2</sub> eq ha<sup>-1</sup> of total greenhouse gas (GHG) emissions annually. This is likely to be the largest source of land use GHG emissions in the UK per unit area and there is interest in developing responsible management approaches to reduce emissions whilst maintaining economically productive systems. Lettuce (Lactuca sativa) is amongst the UK’s most valuable crops and a substantial proportion of UK production occurs in the Fens. We undertook a life cycle assessment to compare the carbon footprint of UK Fen lettuce with alternative sources of lettuce for the UK market. We also examined the potential for responsible peat management strategies and more efficient production to reduce the carbon footprint of Fen lettuce. It is hoped this study will help to inform land use decision making and encourage responsible management of UK lowland peat resources.</p>


2015 ◽  
Vol 37 (3) ◽  
pp. 273 ◽  
Author(s):  
Beverley K. Henry ◽  
D. Butler ◽  
S. G. Wiedemann

In life cycle assessment studies, greenhouse gas (GHG) emissions from direct land-use change have been estimated to make a significant contribution to the global warming potential of agricultural products. However, these estimates have a high uncertainty due to the complexity of data requirements and difficulty in attribution of land-use change. This paper presents estimates of GHG emissions from direct land-use change from native woodland to grazing land for two beef production regions in eastern Australia, which were the subject of a multi-impact life cycle assessment study for premium beef production. Spatially- and temporally consistent datasets were derived for areas of forest cover and biomass carbon stocks using published remotely sensed tree-cover data and regionally applicable allometric equations consistent with Australia’s national GHG inventory report. Standard life cycle assessment methodology was used to estimate GHG emissions and removals from direct land-use change attributed to beef production. For the northern-central New South Wales region of Australia estimates ranged from a net emission of 0.03 t CO2-e ha–1 year–1 to net removal of 0.12 t CO2-e ha–1 year–1 using low and high scenarios, respectively, for sequestration in regrowing forests. For the same period (1990–2010), the study region in southern-central Queensland was estimated to have net emissions from land-use change in the range of 0.45–0.25 t CO2-e ha–1 year–1. The difference between regions reflects continuation of higher rates of deforestation in Queensland until strict regulation in 2006 whereas native vegetation protection laws were introduced earlier in New South Wales. On the basis of liveweight produced at the farm-gate, emissions from direct land-use change for 1990–2010 were comparable in magnitude to those from other on-farm sources, which were dominated by enteric methane. However, calculation of land-use change impacts for the Queensland region for a period starting 2006, gave a range from net emissions of 0.11 t CO2-e ha–1 year–1 to net removals of 0.07 t CO2-e ha–1 year–1. This study demonstrated a method for deriving spatially- and temporally consistent datasets to improve estimates for direct land-use change impacts in life cycle assessment. It identified areas of uncertainty, including rates of sequestration in woody regrowth and impacts of land-use change on soil carbon stocks in grazed woodlands, but also showed the potential for direct land-use change to represent a net sink for GHG.


2016 ◽  
Vol 56 (5) ◽  
pp. 882 ◽  
Author(s):  
Stephen Wiedemann ◽  
Eugene McGahan ◽  
Caoilinn Murphy ◽  
Mingjia Yan

Resource use and environmental impacts are important factors relating to the sustainability of beef production in Australia. This study used life cycle assessment to investigate impacts from grass-finished beef production in eastern Australia to the farm gate, reporting impacts per kilogram of liveweight (LW) produced. Mean fossil fuel energy demand was found to vary from 5.6 to 8.4 MJ/kg LW, mean estimated fresh water consumption from 117.9 to 332.4 L/kg LW and crop land occupation from 0.3 to 6.4 m2/kg LW. Mean greenhouse gas emissions ranged from 10.6 to 12.4 kg CO2-e/kg LW (excluding land use and direct land-use change emissions) and were not significantly different (P > 0.05) for export or domestic market classes. Enteric methane was the largest contributor to greenhouse gas emissions, and multiple linear regression analysis revealed that weaning rate and average daily gain explained 80% of the variability in supply chain greenhouse gas emissions. Fresh water consumption was found to vary significantly among individual farms depending on climate, farm water supply efficiency and the use of irrigation. The impact of water use was measured using the stress-weighted water use indicator, and ranged from 8.4 to 104.2 L H2O-e/kg LW. The stress-weighted water use was influenced more by regional water stress than the volume of fresh water consumption. Land occupation was assessed with disaggregation of crop land, arable pasture land and non-arable land, which revealed that the majority of beef production utilised non-arable land that is unsuitable for most alternative food production systems.


2013 ◽  
Vol 67 (1) ◽  
pp. 63-73 ◽  
Author(s):  
C. Remy ◽  
B. Lesjean ◽  
J. Waschnewski

This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO2, CH4, N2O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (–162 MJ/PECOD * a) and carbon footprint (–11.6 kg CO2-eq/PECOD * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.


2014 ◽  
Vol 918 ◽  
pp. 121-126
Author(s):  
Zhe Liu ◽  
Wei Hua Zeng

Electric vehicles have been gaining increasing worldwide attention as a promising potential long-term solution to sustainable personal mobility in recent years; in particular, battery electric vehicles (BEVs) offering zero tailpipe emissions are favored by a significant number of people in China. However, their true ability of contribution to greenhouse gas (GHG) emissions reductions is invisible. This paper assessed their environmental impacts from the perspective of life cycle. Life cycle assessment is used as the analyzing method and eBlance is applied as a tool to identify the impacts quantitatively.


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