Our project requires an interdisciplinary approach that combines the expertise of the stakeholders within the consortium. We investigate a range of different topics, all related to the aim of developing insects as sustainable feed for a circular economy.
Ethics and welfare
A viable insect sector is dependent on production methods that promote insect health and welfare so as to produce high quality insects in a responsible way, while heeding the intrinsic value of insects.
As a consequence, responsible insect production as feed for livestock raises basic philosophical and practical ethical questions. We will address questions (a) about the moral status or 'intrinsic value' of insects and its implications; (b) what concept of welfare (hedonistic, objective, other?) is appropriate for insects, (c) whether insects display purposive agency, and (d) whether a precautionary approach is appropriate while there is uncertainty about insect capacity to experience pain or suffering. Moreover, we will address (e) how to weigh protection of insect welfare against promotion of welfare of livestock to which insects are fed.
The ethical analysis comprises two related theoretical dimensions: (1) to clarify whether, and in what sense, insects should be attributed moral status and (2) to explore how insect welfare can be best understood, with a focus on the two focal species, i.e. the Black Soldier Fly (BSF) and House Fly (HF). These questions require theoretical philosophical analysis, and we use discussions with other researchers and stakeholders in the programme (e.g. WP1) – and notably articulation of their moral intuitions and their (implicit) normative and conceptual assumptions about insect welfare – as input for our philosophical and normative-ethical analysis. This empirical and theoretical work will be the basis for developing a framework for balancing concerns for insect welfare versus other values, in particular the promotion of welfare of livestock to which insects are fed (WP6). The role of the philosophers in the project is to also promote ethical reflection within the project by organising ethical discussion when needed.
Substrate safety
The insect production sector offers much needed opportunities for upgrading low-quality left-over streams into high-quality protein and lipids for feed and food. Large volumes of low-quality substrates arise from co-products of agricultural crops that are currently not used as feed or food. There are several causes why such crop co-products are unsuitable as food and feed: they contain naturally occurring plant toxins, e.g. leaves of tomato and potato naturally contain toxic steroidal alkaloids and they can contain insecticides that were applied as chemical control agents of insect pests in crop production. Whereas the hazards of endogenous plant toxins have been extensively investigated and contamination with insecticides is being monitored by the NVWA, a third class of chemical contaminants, i.e. mycotoxins, is of rapidly growing concern due to global warming. Mycotoxins are produced by fungi that infected the crops on the field or after harvest. Mycotoxins belong to the most toxic natural compounds known due to their carcinogenic and hepatotoxic effects on livestock species and humans. In this WP we will focus on mycotoxins as major feed safety hazards. Recent research showed that BSF can degrade several mycotoxins without affecting their growth rate, however, no information on effects on HF larvae is available. Moreover, it remains to be identified what the fate of these contaminants is when insects consume them: which in vivo transformation products are produced by fly larvae, are these excreted or accumulated and how do these affect body composition and health of the BSF and HF larvae and adults. The experimental work will be coordinated with the studies on the effects of stress factors on the flies' immune system and behaviour.
Insect health and immune system
Safeguarding insect health is a vital activity of the new sector, in terms of insect welfare, insect quality as feed, economic robustness for insect producers as well as the total sector, and consumer acceptance. Therefore, this WP receives special focus in the total programme.
Insect health, the state of being free from disease or injury, is challenged when insects are exposed to harmful conditions. Pathogenic microorganisms can cause an infection or may lead to food spoilage through the production of various toxins, both of which can induce severe morbidity and mortality. Crowding may inflict wounding when individuals damage each other (e.g. piercing the cuticle with their mouthparts), and may lead to an accumulation of noxious waste products in the food (e.g. ammonia). Sub-optimal temperatures affect physiology and metabolic rates and disrupt homeostasis, in particular membrane and protein integrity, and may induce torpor, sterility and mortality. Consequentially, insects evolved a rich array of defensive mechanisms, including a potent innate immune system, a detoxification system and general stress responses, to cope with infection, wounding, noxious substances and temperature stress80-84. Measuring the activation of these defensive responses provides a tool to assess the conditions that challenge insect health, even well before it leads to externally visible effects.
In nature, larvae of many fly species feed in aggregations on decaying materials that are extensively colonized by microorganisms85. Fly larvae seem to be quite resistant to diseases. Yet, knowledge on the immune system in BSF and HF is limited. Recent studies indicated that the genomes of both HF and BSF contain an elevated diversity of immunity genes that are up-regulated after bacterial infection86,87. Crowding can induce stress and wounding, compromising the immune system. Alternatively, high densities are also known for the phenomenon of 'collective or social immunity', resulting in a constitutive immune activity in the absence of pathogens, which can provide protection against infection. Moreover, flies have close associations with beneficial microbes (e.g. in their gut), that contribute significantly to their fitness and health and may provide protection against pathogenic microbes17. Finally, both the nutritional composition of their feeding substrates and probiotics may strengthen the immune system, making the flies more resistant to stress and infections.
Here, we will investigate the composition of the immune system of the BSF and the HF, and assess what factors in mass rearing challenge, compromise or fortify these systems. We will exploit the extensive knowledge that is available on the immune system and the defensive repertoire of the model fly Drosophila melanogaster that also feeds in aggregations in decaying fruits18,66,88,89, to develop a set of immunological markers in BSF and HF. We will then assess which conditions in mass rearing challenge BSF and HF health (WP4), using these markers as diagnostic tools, and their well-being (WP5). Factors studied will include larval density, pathogens, probiotics, food quality (in connection with WP3), light regimes and temperature.
Insect behaviour and health
In contrast to the situation for vertebrates, surprisingly little is known about how to assess well-being of insects, in particular under mass-rearing conditions. Well-being, as defined by Brambell's five freedoms, can be measured through various indicators, such as behaviour, longevity, disease, productivity and physiology. Arguably, a high reproductive output (e.g. number of offspring produced, offspring size and nutritional composition) may be a good indication that the insects are healthy. However, reproductive output may not accurately reflect the entire well-being spectrum, as it does not address the aspects on behaviour, discomfort, pain and distress. This WP focuses on developing a more comprehensive methodology for measuring insect welfare under mass rearing conditions. We will investigate insect behaviour as affected by insect density, feed quality, temperature, relative humidity and light regime. To assess behaviour in the context of insect welfare, we will quantify insect behaviour and connect this to pathogen infection , and contamination of feed substrate. We will use this information to develop methodology for assessing and quantifying insect welfare in terms of behavioural expression under mass rearing, and to design monitoring protocols for the industrial partners. We will develop methodology for documenting the behaviour of fly larvae and adults.
Livestock health and welfare
BSF and HF are produced for feed. Since 2017 their inclusion in feed for aquaculture has been approved by the European Commission. At present, eggs produced by laying hens fed with BSF are available in Dutch supermarkets. Although insects are mainly seen as a source of nutrients, especially proteins, there are first indications that the inclusion of insects in feed may also enhance the immune system in poultry90. This may result in a reduction in the use of antibiotics in the poultry industry and thus contribute to livestock production without risks for human health due to drug resistance in bacteria. Moreover, preliminary data also indicate that inclusion of insects in feedstuff alters the behaviour of poultry, resulting in reduced stress, feather pecking and thus improved poultry welfare. Here, we will investigate the effects of inclusion of insect products in the feed of broilers and laying hens on performance parameters such as body weight gain, cumulative feed intake, cumulative feed conversion ratio, egg production as well as egg characteristics and blood parameters. Moreover, behavioural observations with respect to foraging and pecking behaviour will be conducted. Live insects may stimulate poultry foraging behaviour, thus reducing aggressive behaviour and increasing poultry welfare. We will compare the effects of including live insects compared to insect meal (EU regulation is expected in 2019). These data will be relevant both for ethical analysis and consumer behaviour.
Economic robustness
Insects as feed offer the challenging opportunity of designing a novel value chain more or less from scratch. In addition, this poses risks because it is a terra incognita in various ways. The knowledge and insights generated by WP1-6 provide a scientific basis for the development of novel insect-feed based value chains for both broiler (meat) and layer (eggs) production. Any value chain, and particularly a novel one, is exposed to a variety of risks that can adversely affect its short- and long-term economic viability. Risks can originate at a certain chain level (e.g. hampered production of feed-insects caused by diseases), between different chain levels (e.g. mismatches between supply and demand of poultry products) or from outside (e.g. changes in consumer preference or institutional changes). Importantly, since insect-feed based broiler and egg production is a new activity, unexpected risky developments (e.g. demand and pricing) should be anticipated. Insight in (1) the likelihood and impact/importance of the various robustness-affecting risks and developments and (2) potential measures to reduce these risks at all stakeholder levels of the value chain is essential for a successful organisation and management of these value chains.
Applying and integrating the essential information and building-blocks provided by the other research projects, this projectwill develop set-ups for both value chains applying stochastic simulation modelling. This allows a comprehensive ex-ante analysis on robustness and resilience for both value chains as a whole, as well as for all participating levels; moreover for the short run (i.e. starting-up phase) and the long run (i.e. established phase). The insights provided in this way will enable future participants and stakeholders to develop, implement and manage such tailor-made novel value chains, both from a production, logistic and marketing point of view, in such a way that production and financing risks will be manageable and anticipatable. Hence, WP7 provides the basis for maximizing the economic robustness and viability of the new developed value chain.