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HAVBRUK2-Stort program for havbruksforskning

Insects as natural feed ingredients for sustainable salmon farming

Alternative title: Insekter som naturlig ingrediens for bærekraftig produksjon av oppdrettslaks

Awarded: NOK 13.3 mill.

Insects could be the fish-feed of the future AquaFly has investigated the potential of insects as a safe and healthy ingredient in future aquafeeds. A main aim of the project was to study the possibility to tailor insect meal as an ingredient in a sustainable feed, covering the nutrient requirements and secure production of robust fish. The marine omega-3 fatty acids EPA and DHA are essential for fish health, insect are able to accumulate up to 7% of omega-3 in its lipid stores. Conventional insect meal is mostly produced from larvae of yellow mealworm (Tenebrio molitor) or black soldier fly (Hermetia illucens; BSF) with a protein composition that has been shown to be highly suitable for Atlantic salmon. We have previously shown that BSF meal could be a good protein source for Atlantic salmon, which also may give environmental benefits. AquaFly studied in depth the safety aspects in insect production and salmon production. The impact on sustainability of using insects as feed ingredients for farmed Atlantic salmon was also studied. During the first year of the project seaweed species were collected by NIFES in collaboration with our project partners at NIBIO and the National University of Ireland Galway. The seaweed samples were analysed for nutrient and contaminant composition at NIFES, and insect feeding studies were carried out in both black soldier fly (BSF) at Protix Biosystems BV (The Netherlands) and with kelp fly (KF) at University of Stirling (Scotland). We found that BSF can live and grow on a diet of 100% grounded seaweed although the growth of the larvae was reduced when seaweed constituted more than 60 % of the media. A higher inclusion of seaweed resulted in a higher percentage of unsaturated FA (of total lipids) including omega-3 fatty acids in the insects. EPA, but not DHA, was found in both BSF and KF larvae grown on media containing seaweed. A higher EPA concentration in the feeding media resulted in a higher EPA concentration in the insect. The same was found for iodine, cadmium and arsenic that all accumulated in the insects in a dose-dependent manner. A freshwater feeding trial was performed at the research facilities of EWOS in Dirdal. A standard diet containing fish meal and soy protein concentrate (50:50) and fish oil and vegetable oil (33:66) was fed to the control group. Experimental diets were produced where 85% of the protein was replaced with insect protein and/or all the vegetable oil was replaced with insect oil. This resulted in diets with up to 65% inclusion of insects. After 8 weeks of feeding no differences were recorded for initial or final body weight, body length, food conversion ratio, condition factor, feed intake, protein productive value or lipid productive value. The hepatosomatic index and viscerosomatic index were higher in the insect meal fed groups compared to the control, due to a higher hepatic and intraperitonal lipid content. Investigations into the intestinal health showed no negative effects of high insect meal inclusion in the diet. Finally, a seawater feeding trial was conducted at Gildeskål Research Station (GIFAS) in Inndyr. In this experimental trial, aquafeeds were designed with total and partial substitution of fishmeal (FM) by insect meal (IM). A reference diet with a combination of FM and vegetable meal (VM) as protein source and fish oil (FO) and vegetable oil (VO) as lipid source was fed to the control group. Three experimental diets were formulated wherein 33, 66 and 100% of FM protein source was replaced with IM. Fish were fed these diets from around 1.2 kg size up to slaughter size (4-4.5 kg). Replacing the dietary fish meal with insect meal did not affect the apparent digestibility coefficients of protein, lipid, amino acids or fatty acids. Feed intake, daily growth increase, and feed conversion ratio were also unaffected by the inclusion of insect meal in the diets. The sensory testing of the fillet revealed no changes in the fillet sensory quality. A sustainability (economic, environmental and social) analysis has been performed by NIBIO, University of Bergen and the Autonomous University of Barcelona. A survey of organic streams in Norway that could serve as insect feed has been carried out by NIBIO. Moreover, different scenario?s have been modelled where the sustainability of insect meal was put in context of other alternatives. The outcomes of these studies will be published in 2019.

AquaFly has had an active dialogue with various stakeholders, like Mattilsynet, feed producers, fish farmers and insect producers. AquaFly has been very important in creating an awareness of this emerging area and we have seen the establishment of several companies during the past 4 years with which we have had close contact in two RFF projects. The tests performed and published in AquaFly has helped creating a basis for the legislation to open up for this new feed ingredient. The first commercial use of insect in fish feed was in 2018. With the allowance of insect meal in commercial diets other questions have arisen, e.g. how to identify insect meal in fish feed. This has resulted in project ENTOFOR from the BIONÆR program.

The purpose of AquaFly is to develop and utilize novel safe and healthy raw materials not used directly for food as ingredients for salmon feed that contributes to the goal of a sustainable aquaculture. Insects are outstandingly powerful organisms that ha ve the ability to upgrade less favorable organic resources to highly nutritious feed ingredients. The potential for insect meal as a suitable protein source for Atlantic salmon has been demonstrated by NIFES. AquaFly aims to develop novel insect meal and oil ingredients for Atlantic salmon diets contributing with essential nutrients to sustain fish health and welfare. To achieve this goal, tailoring of insect meal nutrient composition towards Atlantic salmon nutrient requirements, such as marine omega-3 f atty acids, is required. All raw materials contribute with undesirable substances, and AquaFly will monitor the undesirable substances including pathogens in the whole production chain from insect feed to fish fillet. Particularly, arsenic and cadmium co ncentrations is a challenge in some macro algae, and increased knowledge of the transfer efficiency from waste stream to insects to feed ingredients to fish fillet is necessary for evaluating macro algae and tunicate waste as relevant substrates for insec t lipid and protein production. The most promising macro algae and tunicate will be selected as insect feed based availability from wild stocks and aquaculture, nutrient composition and concentrations of undesirable components. AquaFly will increase know ledge of the potential of a new insect species, Kelp fly, for commercial fish feed ingredient production. Main AquaFly end points to assess the potential of insect raw materials for Atlantic salmon are the impact of maximum inclusion of insect protein an d lipids on production of robust fish, feasibility of insect ingredients as an industry for aquaculture, and sustainability in a broad sense, as well as ethical aspects of insects in the seafood production Chain

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Funding scheme:

HAVBRUK2-Stort program for havbruksforskning