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The potential of co-products to reduce the environmental impact of pig systems

Lookup NU author(s): Dr Stephen MacKenzie, Dr Ilkka Leinonen, Professor Ilias Kyriazakis


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Implications Increased inclusions of co products, such as bakery meal and wheat shorts in pig diets can reduce the Global Warming Potential and Non-Renewable Resource Use of pig systems. Introduction Previous Life Cycle Assessment (LCA) studies have shown that feed production causes the majority of Global Warming Potential (GWP) and Non-Renewable Resource Use (NRRU) (Mackenzie et al, 2014) resulting from pig systems. The level of Acidification Potential (AP) caused by pig systems is sensitive to the efficiency of nutrient supply in the diets to meet pig requirements. The aim of this study was to investigate the effect that including alternative feed ingredients (co products) in Grower/Finisher (G/F) diets can have on the GWP, AP and NRRU of Canadian pig systems. Material and methods The diets were tested using an LCA model for pig systems in Canada (Mackenzie et al, 2014) which calculated the GWP, AP and NRRU of the system per kg of carcass weight. The land use change methodology followed PAS 2050 guidelines (BSI, 2011). All diets were formulated on a least cost basis using Canadian price data for 2013 and the Stein Monogastric Nutrition Laboratory nutritional matrix (2014). All diets (except the Least Cost across the G/F phase (LCGF) diet) had nutritional specifications designed for optimum feed efficiency following expert advice from industry and had four feeding phases. The control (C) diet was based on corn, soymeal, canola meal, a fat blend, limestone, amino acids, minerals and additives. 4 diets were formulated for a maximum inclusion of meat meal (MM) (5 - 7.5%), bakery meal (BM) (7.5-10%), corn DDGS (DDGS) (20-30%) and wheat shorts (WS) (20-40%) in G/F diets. Results were generated using 1000 Monte-Carlo (MC) simulations; each diet was compared to the control using parallel simulations accounting for shared uncertainty. Two further diets were formulated; one at least cost for optimum feed efficiency (FE) with BM (8.22%) and WS (2.49%) and one for least cost across the G/F phase (LCGF) accounting for compensatory feed intake with BM (8.69%) and WS (18.9%). Parallel MC simulations were used to compare the environmental impacts of the system using these two diets. Results The BM diet produced small reductions (P <0.001) in the environmental impact of the system for all categories tested (table 1). The MM diet reduced NRRU (P <0.001), did not significantly affect GWP and increased AP (P <0.001). DDGS caused a small reduction in AP (P = 0.01), but increased GWP and NRRU (P <0.001). The WS diet caused the largest reductions in GWP and NRRU (P <0.001) and did not significantly affect AP. The LCGF diet had lower NRRU than the FE diet but increased AP caused by the system (P <0.001), GWP was not significantly different between the scenarios. Table 1 The environmental impacts of 1 kg expected carcass weight in Canadian pig systems using different G/F diets. GWP (kg CO2 e) AP (g SO2 e) NRRU (g Sb e) Mean s.d. %<C1 Mean s.d. %<C1 Mean s.d. %<C1 C 2.20 0.19 N/A 57.4 4.2 N/A 6.52 0.90 N/A MM 2.16 0.20 81 61.6 5.0 0 5.95 0.82 100 BM 2.13 0.18 100 56.7 4.1 100 6.30 1.04 100 DDGS 2.58 0.21 0 57.1 4.0 99 10.3 1.8 0 WS 1.97 0.18 100 57.6 4.2 29 5.34 1.16 100 Mean SD %< FE1 Mean SD %< FE1 Mean SD %< FE1 FE 2.16 0.19 N/A 56.1 4.3 N/A 6.42 0.91 N/A LCGF 2.12 0.19 88 58.4 4.3 0 5.84 0.97 100 1 %<C= Percentage of results which were smaller than the control diet, %<FE = Percentage of results which were smaller than the least cost diet for optimum feed efficiency Conclusion It is possible to reduce the environmental impact of Canadian pig systems through the increased inclusion of co products. Increased WS and BM inclusions reduced the environmental impact of the system with no increase in any of the impact categories tested. The increased inclusion of co-products in the LCGF diet had a mixed effect on the environmental impacts in comparison to the FE diet reducing NRRU but increasing AP resulting from the system. Acknowledgements Funding and data for this research was provided by Nutreco Canada References FAO. 2013. Greenhouse gas emissions in pig and chicken supply chains. FAO. Rome. Mackenzie, S., Leinonen, I., Ferguson, N. and Kryiazakis, I. 2014. Proc. 9th Int. Conf. of LCA in Agri-Food. Available online: BSI. 2011. PAS 2050: Specification for the assessment of the lifecycle greenhouse gas emissions of goods and services. BSI. London. Stein Monogastric Nutrition Laboratory. 2014. Feed Ingredient Database. Available online:

Publication metadata

Author(s): Mackenzie SG, Ferguson N, Leinonen I, Kyriazakis I

Publication type: Conference Proceedings (inc. Abstract)

Publication status: Published

Conference Name: Advances in Animal Biosciences - Science with Impact - BSAS

Year of Conference: 2015

Acceptance date: 01/01/1900