Environmental impacts and resource use from Australian pork production assessed using life-cycle assessment. 1. Greenhouse gas emissions

Abstract

Abstract. 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 CO 2 -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 CO 2 -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 CO 2 -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 AE 1.03 kg CO 2 -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.

Organic Farming as a Strategy to Reduce Carbon Footprint in Dehesa Agroecosystems: A Case Study Comparing Different Livestock Products

“…The protein that soy adds to the pig's diet is essential, but the production of soy is limited in Europe, hence requiring importation from third countries, mainly America and China. In the paper written by Wiedemann et al [77,78] in Australia, the average calculated was 2.1 to 4.5 kg CO 2 eq/kg of LW.…”

Review: Insect meal: a future source of protein feed for pigs?

“…As the demand for animal proteins increases, the gap between supply and demand of feed protein will continue to increase. Soybean meal, the major feed plant protein source included in monogastric animal diets, has a large environmental impact due to land and water use to grow soybeans and the large-scale transportation of this commodity (Wiedemann et al, 2016). Soybean meal availability for animal feed can be limited due to its use in human food streams and low productivity; and in Australia most soybean meal is imported from the US and South America (M'Gee, 2011).…”

Practical options for cleaning biogas prior to on-farm use at piggeries

“…A recent life cycle assessment study (Wiedemann et al, 2016) suggested that piggery GHG emissions could be reduced by changing housing/manure management systems, with the greatest reductions achieved by installing biogas capture and combined heat and power systems (CAP-CHP), resulting in total emissions reductions up to 64%. Clearly, the wide adoption of biogas capture, treatment and use systems by Australian pork producers would be crucial for the achievement of the proactive industry goals noted above.…”

“…Biogas may not need to be upgraded before being burnt in boilers (Table 1. 1). However, at H2S concentrations higher than 1000 ppm, the formation of sulphuric acid is likely to result in serious corrosion (Wellinger et al, 2013).…”

“…The wide adoption of this technology could substantially advance the Australian pork industry towards meeting its adopted on-farm greenhouse gas (GHG) emissions target cap of 1 kg CO2-e per kg of pork produced (Pork CRC, 2015). A recent life cycle assessment study (Wiedemann et al, 2016) suggested that the greatest reductions in piggery GHG emissions could be achieved by installing biogas capture and One of the major obstacles impeding the widespread adoption of biogas technology onfarm in Australia, is the presence of relatively high concentrations of hydrogen sulphide (H2S) in raw biogas collected from pig manure treatment. These concentrations are commonly in the range of 500 to 3000 ppm H2S (Safley and Westerman, 1988;FNR, 2005;Craggs, 2010 andSkerman, 2013).…”