Black soldier fly meal : A highly digestible protein source for aquafeeds
by Agronutris, France
As aquaculture production is expected to increase in the next few years, implying a significant increase in the need for alternative proteins by 2050, insect meal appears as a sustainable protein source to answer the challenges of the industry.
The long-lasting growth of the aquaculture sector is putting growing pressure on protein resources for aquafeeds. A recent study by Lux Research highlighted that, by 2050, the industry will need 15 million tonnes of alternative proteins, among which insect proteins are set to play a key role. The many assets of insect meals have been increasingly highlighted in the past few years: they are rich in proteins and essential amino acids, highly digestible, have interesting amounts of polyunsaturated fatty acids and show no adverse effect on palatability (Makkar et al., 2014 ; Zamprogna et al., 2017).
Furthermore, insect production falls within a circular economy process, as larvae are often fed with underused byproducts, thus reintegrating low-value materials into the feed chain. Among the various insect species reared for protein production, the black soldier fly, or BSF (Hermetia illucens) appears as a particularly promising sustainable alternative to tackle the forecasted shortage of protein for aquafeed.
Agronutris, a French biotech company based near Toulouse, specialises in rearing and processing black soldier flies into proteins for animal nutrition. In the R&D centre, entomologists, engineers and agro-industry experts are developing efficient and sustainable practices to rear BSF on a large scale. Efforts are being made to optimise the diet of the larvae, directly impacting their nutritional content, in order to better match the requirements of the aquaculture sector. The R&D pilot also allows the team to gain extensive know-how on the management of the breeding conditions. Temperature, hygrometry, air flow, light, shape and organisation of the cages are some of the many parameters that are being challenged to reach the best reproduction performances of the flies.
The insects reared at Agronutris are fed with locally sourced byproducts from the agro-industry allowing the company to be a major actor in the development of a circular economy in the aquaculture sector. Black soldier fly larvae are exceptionally efficient at bioconverting low-value substrates into biomass: in less than 14 days, a larva multiplies its weight by about 10,000 times over. Once mature, the larvae are dehydrated and processed into a protein-rich defatted insect meal. The implementation of BSF meal in the diet of aquaculture fish offers a sustainable alternative to fishmeal.
To test the effects of BSF meal when fed to fish, digestibility trials have been performed with two major European institutes specialized in aquaculture nutrition: Sparos and INRAE (French National Scientific Research Institute) on European seabass (Dicentrarchus labrax) and rainbow trout (Oncorhynchus mykiss) respectively. In each test, the apparent digestibility of major nutrients of a test diet formulated by replacing 30 or 15 percent of a reference diet (containing at least 25% fish meal) with BSF meal has been evaluated. Trials were performed with sufficient replicates and individuals to ensure statistically robust values.
Results show that Agronutris BSF meal is highly digestible in terms of protein, fat and energy in both species.
'Agronutris BSF meal can be considered as a highly digestible source of protein, essential amino acids, fat, phosphorus and energy for European seabass, with apparent digestibility coefficient values falling within the range of those commonly found in fishmeal' concluded Sparos report.
Indeed, with more than 62 percent protein and 11 percent highly digestible lipids, BSF meal definitely stands out as an interesting ingredient for aquaculture stakeholders willing to reduce their impact on marine life by partially replacing fishmeal in their diets. These results show a real opportunity, as confirmed by INRAE experts, 'Digestibility results of the tested insect meal open interesting perspectives for its incorporation in the future eco-friendly feed for aquaculture trouts'.
To further investigate the effect of BSF meal in fish feeds, an on-site trial is to be launched on Salmonids as a joint collaboration with the aquaponics company Eauzons! located in Occitanie, France, close to Agronutris pilot. Indeed, previous studies have shown that BSF meal benefits from strong feed acceptance and palatability, and could effectively replace up to 100 percent fishmeal in Atlantic salmon (Salmo salar) diet (Li et al., 2020).
Relying on 10 years of farming, R&D and on an experienced team that has already run or built several factories in the agro-industry, Agronutris has chosen for its scale-up an integrated approach to run the project. It allows the team to focus on the most strategic activities that include insect biology and operational management of flow. Since the beginning of 2019, Agronutris and Bühler have signed a strategic agreement for France. Today, the two companies have finalised the complete feasibility of the plant that should be operational in the last quarter 2021.
Environmental awareness is one of the core values of Agronutris, therefore the company decided to set-up its plant in Rethel, North-East of France, a region with strong agricultural activity and a large production of byproducts that can be sourced as feedstock to be converted into proteins by BSF larvae. The company has already secured the necessary volumes for this factory through long term contracts.
Beyond the environmental positive impact that this solution brings, the company has a holistic approach of sustainability where sustainable performance comes from three complementary levels of focus: the purpose, the human dynamics and the ecosystemic impact. The company is eager to innovate in its social interactions, both within the company and through its interactions with its ecosystem. Agronutris innovates permanently in its management and governance practices by promoting collective intelligence, transparency, freedom, subsidiarity, volunteering... It gives to each collaborator the freedom to declare himself to be part of any decision and to take the lead on any topic.
By providing products of high and constant quality, with their efficacy proven by well-known institutes and promoting a new kind of relationship with its stakeholders based on transparency and a fair sharing of the value created, Agronutris aims to be a trustable actor to provide sustainable solutions for the aquafeed industry.