Implementing Insect Production in Agricultural Value Chains - An ex-ante life cycle evaluation
An ever-growing demand for animal based food products is affecting the productivity of global food production systems, and urgently needed measures to curb further environmental degradation promise similar effects. Whether future demand scenarios can be met sustainably, depends not least on whether it is possible to significantly reduce the environmental impact of aquaculture and livestock production. Recent research suggests that the use of insect based feeds (IBFs) could make a significant contribution in this regard, and in fact valid arguments are put forward to support this conjecture. Fly larvae, like those of houseflies (Musca domestica) or black soldier flies (Hermetia illucens), are able to source nutrients from a wide range of different organic resources, including those unsuitable for human consumption. This creates the opportunity to convert (and significantly reduce) low-value organic wastes, such as manure or animal blood, into high-quality proteins and dietary energy, proven to be suitable for feeding different aquaculture fish and monogastric livestock.
Although the IBF concept promises great benefits and has demonstrated its technical feasibility, there are as of yet no established systems by which conjectured sustainability benefits could be tested. In this thesis we tried to overcome this shortcoming by modelling such systems. Our central objective was to identify the aspects influencing the application potential of IBFs in different geographical contexts and delineate optimization pathways for a sustainable implementation. Drawing on experimental data gathered from rearing trials in Europe (Spain and Slovakia) and West Africa (Ghana and Mali), we formulated the design of a set of up-scaled system versions rearing M. domestica and H. illucens on different low-value organic substrates. The generic production models served as a basis for an ex-ante life cycle analysis, in which we explored the systems’ performances using environmental life cycle assessments (LCAs) and life cycle costing (LCC).
The LCC and LCA analysis showed that the environmental and economic performance of IBFs are largely a function of the systems’ conversion efficiency, the organisation of the production process (i.e., input of labour and technological equipment), and the geographical context. The combination of these factors provided advantages for the simplistic setups used in the production of M. domestica under conditions of natural oviposition (i.e., substrate inoculation through naturally occurring flies) in tropical West Africa. Artificial inoculation (i.e., substrate inoculation through nurtured larvae from a captive adult colony), driving the production of H. illucens in West Africa and M. domestica in Southern Spain, facilitated a high conversion efficiency but raised environmental impacts and costs, as the complex system setup and labour intensive process organisation substantially increased inputs of labour and production infrastructure.
A benchmark comparison with conventional protein-rich feeds pointed towards environmental and economic disadvantages of current IBF production designs, especially in reference to plant based feeds (e.g., soybean meal). The disparities between IBF and conventional feeds mirror the systems’ sub-standard capacity utilisation (insufficient economy of scale effect), as well as the loss of energy and biomass along the trophic chain (autotroph producers vs. heterotroph consumers). These findings raise legitimate doubts as to whether an implementation of insects in present agricultural value chains offers any sustainability benefits compared to conventional feeds. Commercial success greatly depends on the site-specific wage level, the prices of rearing substrates and how markets rate the multiple functions insects are capable to deliver. As it concerns the environmental performance, our results lead us to conclude that the production of IBFs offers no advantages over conventional feeds.
The assessment of yet hypothetical production systems involved a fair amount of assumptions and approximations. Given these multiple sources of uncertainty, and taking into account that only a limited number of possible system designs are considered, statements on the application potential of IBF hold no universal validity and should be interpreted with caution. However, our findings contribute to a better understanding of the factors influencing the application potential of insect production systems and serve as a valuable point of reference for scientific discussions and future research and development activities aiming for sustainable food production patterns.
While our research offers no support for conjectured environmental or economic advantages of using insects as feed, it might be that their use as food for direct human consumption (i.e., as a possible substitute for fish and meat products) provides a sustainable solution to current and future food problems. We therefore advise future research to focus on techniques enabling the exploitation of insects as food.