Life cycle sustainability assessment of a novel slaughter concept

Highlights

• The Meat Factory Cell (MFC) is a revolutionary modular robotics-based concept for slaughtering, cutting and deboning meat;.

• The MFC does not notably change the environmental profile of a pig abattoir.

• The MFC concept is an economically and socially viable alternative.

• The Life Cycle Sustainability Assessment shows that there is a trade-off between the three dimensions of sustainability.

Abstract

This article presents a Life Cycle Sustainability Assessment of an innovative slaughter concept, i.e., a semi-automated version of the Meat Factory Cell (MFC). The system is characterised by division of labour with close human-robot interaction, as compared to a Conventional Slaughter and Cutting Process (CSCP). A case study is built which considers the conditions at a Norwegian slaughter facility. Several assumptions are made for the MFC as the concept is still in the development phase. A sensitivity analysis has been employed to highlight the key factors leading to changes in the environmental, economic and social aspects of the Life Cycle Sustainability Assessment framework.

The results show that MFC is a viable alternative to CSCP within a life cycle sustainability assessment, even though there is a trade-off between the three dimensions of sustainability and variability among the considered impact categories. At the slaughterhouse, the climate change performance for the CSCP is 387 kg CO_2eq/ton carcass. For the MFC concept, results showed no substantial changes in the environmental performance. For the Life Cycle Costing, the difference between the two concepts arises primarily from lower energy costs due to a 50% reduction in the cost of chilling. From a cost perspective, the innovative concept is relatively more profitable for small and medium-size abattoirs than for very large slaughterhouses. The social LCA indicates that a more efficient abattoir system using MFC might lead to the loss of low-skilled jobs but creates opportunities for more qualified personnel.

Introduction

The pig meat sector is the largest single contributor to global meat production (over 37 percent) and worldwide, the demand for pork is expected to rise by over 35 percent by 2030 (MacLeod et al., 2013). Achieving sustainable production whilst satisfying consumer demand is a priority within the meat industry. To maintain low unit costs, despite high labour expenses, is a big challenge for the meat industry in Norway. Automation of slaughtering, cutting and deboning might provide a solution, but today it is only affordable to the largest international producers.

The Meat Factory Cell (MFC) concept (Fig. 1) involves a reorganisation of processing from production lines to workstations, or ‘cells’, where the carcass is disassembled from the outside in Alvseike et al. (2018). The MFC is semi-automated and utilises the principle of co-operative robotics, where robots perform relatively simple, repetitive and labour-intensive tasks (e.g. lifting, holding, stretching), while a human operator performs more complex functions (e.g. detailed cutting). The MFC concept runs an individualistic approach (one cell per operator). The MFC aims to generate more sustainable meat products in contrast to conventional abattoirs in smaller market situations. These can be inefficient due to low volumes, long transport distances, non-specialized slaughterhouses and low workforce density.

The Life Cycle Sustainability Assessment (LCSA) concept is the integration of the environmental Life Cycle Assessment (E-LCA), Life Cycle Costing (LCC) and Social LCA (S-LCA) methodologies (Kloepffer, 2008). According to the guidelines from UNEP/SETAC (2011), the LCSA framework helps to evaluate all environmental, social and economic aspects of products throughout their life cycle. Even though it is not a standardised framework, the number of publications related to LCSA has steadily increased over recent years. Costa et al. (2019) cite 144 published or in press articles in their systematic review of LCSA literature. Fauzi et al. (2019) describe the LCSA as “a promising holistic method”. Several practitioners have already started implementing LCSA to explore its potential to measure sustainability and there is an increased interest in using this methodology (Costa et al., 2019). However, LCSA is still developing its theoretical basis, with half of the articles reviewed by Costa et al. (2019) being reviews, methodological developments, and viewpoints.

There are several ways to conduct LCSA, but the conceptual formula of Kloepffer (2008), i.e. LCSA = E-LCA + LCC + S-LCA is the most used approach and applied in the UNEP/SETAC guidelines (2011). The immaturity of this method is mainly associated with the definition of a coherent system boundary due to a lack of background data, inconsistency among the three pillars of sustainability and difficulties in applying the allocation criteria (especially for the social dimension). In the impact assessment phase, a lack of harmonization among each single method (E-LCA, LCC and S-LCA) and their interaction is highlighted. In the interpretation phase, sensitivity and uncertainty analyses are not completely covered or discussed. Communication of the results is also challenging. The main barriers are linked to the difficulties in applying the LCC and S-LCA (the most immature method within LCSA) in a life cycle thinking perspective.

There are currently few studies regarding sustainability assessments of meat supply chains in the literature. A study by Petit et al. (2018) assesses the sustainability performance of a pork value chain in France by presenting new metrics for stakeholders willing to work with the sustainability of their supply chain. A hotspot approach is used by interviewing stakeholders involved in the pork value chain. Petit et al. (2018) affirm that no one framework is appropriate for the sustainability assessment (from farm to consumers) and therefore the authors propose an assembly of different frameworks currently available in the literature. A study by Schmitt et al. (2017) applies a multidimensional approach to assessing the sustainability of local and global food products, including a case study for ham in Italy. Local products perform better in relation to quality and place (territoriality, nutrition, animal welfare), while global product perform better in quantity management such as affordability and food safety. The study concludes that any selection of indicators will not cover all aspects of sustainability and a level of uncertainty is shown in the assessment. de Boer et al. (2011) suggest that greenhouse gas mitigation in animal production needs to be regarded in an integrated manner, i.e. in an LCSA context. Mesarić et al. (2016) analyze the supply chain of pork meat in the context of LCA and sustainability in Croatia, from cradle to grave. The result of this study shows a loss in the value added due to an imbalance generated by the decreased production of meat in Croatia, in contrast to the increase in imports. Recent studies have suggested the inclusion of animal welfare as part of the social assessment of meat value chains (Neugebauer et al., 2014; Scherer et al., 2018; Tallentire et al., 2019). Despite some efforts, most life cycle studies on meat production and slaughterhouse practices still consider E-LCA, LCC and S-LCA in separation.

E-LCA, or simply LCA, is standardized by ISO 14044 (ISO, 2006), and considers environmental impacts across the life cycle of a product, process or service. There are various types of LCAs, such as attributional, consequential, hybrid and Input-Output LCA. Of these, attributional LCA is often found to be the most commonly used (Pohl et al., 2019). According to ISO 14044, LCA can only provide potential and indicative results, and the robustness of an individual LCA might in some cases be low. Further, uncertainty is an underdeveloped aspect in many LCA studies, largely due to the difficulties of establishing and quantifying all types of uncertainty. In fact, 80% of LCA studies do not consider uncertainty at all, perhaps because including some but not all sources of uncertainty could lead to misleading results (Bamber et al., 2020). Nevertheless, LCA is routinely considered to be the most comprehensive way of assessing the environmental impact of products, processes and services.

As opposed to few LCSA studies, many LCA case studies of pork have been conducted and there is wide variation in the results. Most studies show that animal feed has the greatest environmental impact, while the actual slaughtering process contributes little in the overall life cycle. There is often a focus on global warming potential (GWP) (Bonesmo et al., 2012; Jacobsen et al., 2014), but eutrophication, acidification and energy use are also common impact categories in the LCA of pork (Bonou and Birkved, 2016; Devers et al., 2012; Winkler et al., 2016). A minority of studies also include land occupation (Dourmad et al., 2014; Johansen and Roer, 2018; Nguyen et al., 2011; Noya et al., 2017) and other impact categories, such as water use (Weidemann et al., 2010), pesticide use (Basset-Mens and van der Werf, 2005), human health damage, ecosystem diversity and resource availability (Stone et al., 2012). The greatest methodological challenges are related to allocation in feed production, manure (Noya et al., 2017) and byproducts from slaughtering.

Life cycle costing (LCC) was originally an approach for evaluating costs across the life cycle of a product, e.g. from the procurement of a product to its disposal (Woodward, 1997) or from the design phase of a product to its launch (Asiedu and Gu, 1998). This gives a more comprehensive picture of costs than direct investment costs alone. In the context of LCSA, what is properly called environmental life cycle costing is a form of LCC in which the scope is harmonized with that of environmental LCA (Settanni, 2008). On the initiative of SETAC, Swarr et al. (2011) developed a generic code of practice for LCC, and Heijungs et al. (2013) proposed a computational structure for LCC. Neugebauer et al. (2016) proposed a more comprehensive form of economic life cycle assessment, EcLCA. Miah et al. (2017) describe the differences in scope between LCA and LCC, and several practical approaches that have been used for integrating the two. Toniolo et al. (2020), in turn, suggest a ten-step procedure for LCC development. Despite this body of recommendations, LCC in an LCSA context remains an ad hoc exercise, and which life cycle stages are included and how comprehensively they are modelled will often be determined by practical limitations such as data availability. Databases for the background system exist for LCA (e.g. Ecoinvent), but not for LCC.

S-LCA shares common ground with E-LCA about the scope of analysis (the entire life cycle of products) and to the focus on impacts.

In the context of meat, Neugebauer et al. (2014) propose a list of social indicators for the pork value chain, addressing the stakeholder categories: workers, local communities, consumers and also animals. Lagarde and Macombe (2013) assess the social changes arising from the introduction of a competitive pork value chain in comparison to a conventional value chain. The authors propose a way of calculating the number of rural jobs created/destroyed by the implementation of a new value chain. Macombe et al. (2018) assess the social effects which might result from the development of local production, but due to difficulties in sharing the knowledge from the meat actors, the case study was suspended. Despite these applications, S-LCA is still a methodology “under continuous development” (Di Cesare et al., 2018), due to a lack of harmonization, leading to subjective assessment and interpretation of the results (Arcese et al., 2018). Social data are often qualitative, hard to access, measure and organize. No consensus regarding the most important social impacts exists for S-LCA, in contrast to E-LCA (at least for climate change). Hence, the choice of indicators and impact categories might be subjective. Many challenges are highlighted in S-LCA e.g. in the definition of system and in the use of diverse cut-off criteria (Dubois-Iorgulescu et al., 2018). However, the guidelines, currently under revision (UNEP/SETAC, 2009), and a handbook (Fontes et al., 2016) are helping the development of a more harmonized methodology.

To our knowledge, this paper is the first LCSA study to be published on robotification. Hence, our overall goal is to perform a Life Cycle Sustainability Assessment analysis to compare two approaches to slaughtering and cutting pork carcasses at a slaughterhouse: a Conventional Slaughter and Cutting Process (CSCP), i.e. today’s system and an innovative concept i.e. the Meat Factory Cell (MFC).

The main goals are:

• To assess and compare the potential environmental, economic and social impacts of the two concepts and to demonstrate how LCSA can be applied to a case study;

• To conduct a sensitivity analysis to measure the robustness of the LCSA results for the MFC concept by highlighting the effect of changing the most critical input data;

• To present and discuss the results in a holistic perspective, thus integrating all the three aspects of LCSA.