Life cycle assessment of Japanese pig farming using low-protein diet supplemented with amino acids

Abstract

Livestock production is indicated to be one of the major emitters of greenhouse gases (GHG), particularly methane (CH 4 ) and nitrous oxide (N 2 O), around the globe, and the reduction of these emissions is an important goal. GHG emissions as well as other environmental impacts of two pig (Sus scrofa domesticus) farming systems, one using conventional diets (CNV) and the other using low-protein diets supplemented with crystalline amino acids (LOW), were therefore evaluated by comparative life cycle assessment (LCA) focusing on manure management and by cradle-to-farm gate LCA. The functional unit was defined as one marketed pig. For the comparative LCA of manure management, the CH 4 and N 2 O emissions from manure management of CNV were set as a baseline, and the system boundary of LOW included the CH 4 and N 2 O emissions from manure management, and changes in the GHG emissions from feed production including amino acid manufacturing, feed transport, and the materials and energy consumed in manure management. For the cradle-to-farm gate LCA of pig farming, the evaluated system included the processes of feed production including amino acid manufacturing for LOW, feed transport, animal housing including the biological activity of the animal, and manure management. The results of the comparative LCA showed that the GHG emissions from manure management of LOW were 20% less than those of CNV, and the GHG reduction rate of LOW compared to CNV was even greater in the case of a stricter target of effluent nitrogen content. The results of cradle-to-farm gate LCA showed that LOW had lower GHG emissions, acidification potential, eutrophication potential and overall environmental impact, and slightly larger energy consumption, than CNV. The sensitivity analysis showed that LOW still had less GHG emissions than CNV, even in the least preferable case assuming a 40% lower reduction rate of nitrogen excretion.

Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice

“…Feed input efficiency in livestock systems can also be increased. For example, pork from pigs fed diets supplemented with amino acids required less feed and emitted 5% fewer GHGs and had 28% lower eutrophication potential than pork from pigs fed unsupplemented diets (Ogino et al 2013). Similar benefits have also been found in poultry, beef, and dairy systems (Robertson and Vitousek 2009).…”

Effect of observed individual data of performance and excretion on life cycle assessment of piglets

“…Global warming . v.76, n.2, p.102-111, March/April 2019 potential associated with IAA production is higher per kg of product than for grain or soybean meal production (Ogino et al, 2013). The benefits of the IAA addition related to the reduction of nitrogen excretion during housing and, consequently, lower nitrogen gaseous emissions, might compensate for the higher impact of low CP diet.…”

“…Nitrogen and phosphorus contribute to the eutrophication process and nitrogen contributes to the acidification process by ammonia emissions (Guinée et al, 2002). For this reason, most research evaluating the effect on dietary CP reduction for pigs reported a reduction on AP and EP with low CP diets (Ogino et al, 2013;Garcia-Launay et al, 2014;Mackenzie et al, 2016;Kebreab et al, 2016). In the above-mentioned researches, data were not evaluated statistically and the effect of between-animal variability was also not taken into account.…”

Life cycle assessment as a tool to evaluate the impact of reducing crude protein in pig diets

“…In the study of OGINO et al (2013) AP and EP per kg of pig produced were reduced by about 2 and 9%, respectively, for each percentage unit of CP content reduction. Likewise, GARCIA-LAUNAY et al (2014) reported that the reduction of dietary protein content lessened the AP impact by about 5% and the EP impact by about 3%, for each percentage unit of CP content.…”

“…Evaluating the environmental impacts of pig production with a conventional or a low CP diet in a Japanese system, OGINO et al (2013) reported that the low CP diets resulted in a lower GWP (6%) per pig produced than conventional diets. This represented a 2% reduction in the GWP for each percentage unit of CP content.…”