Insects: A sustainable feed ingredient for aquaculture

The ever growing aquafeed industry is actively looking for novel protein sources and functional ingredients. The insect farming industry is also developing at a fast pace to supply the market with premium sustainable and functional insect proteins as they are the perfect candidates to answer to these challenges.

Dr. Emilie Devic
R&D Manager
Entofood, Malaysia

Naturally, wild fish feed on insects or other invertebrates. Therefore, incorporating insect proteins into aquaculture species diets is neither absurd nor innovative.

According to FAO there are 1,900 identified edible insect species. However, considering the global interest and the number of companies developing Black Soldier Fly (BSF, Hermetia illucens) production systems, it is reasonable to place the focus on this species.

The BSF is a widespread, non-harmful dipteran insect that is able, at the larvae stage, to convert a broad range of organic materials into protein and energy-rich biomass and natural fertilizer (i.e. insect droppings, also called “frass”). Besides, its short life cycle, high prolificacy and ability to withstand high individual density make this insect ideal for mass-production.

Extensive research has been conducted over the last decade to evaluate the nutritional benefits of different insects.

Dry BSF larvae contains between 30-58% protein and 10-40% lipids.

Lipid content and fatty acid (FA) composition of the BSF larvae are strongly influenced by its feeding regime and does not meet the requirements of most aquatic farmed species as it is high in saturated FA and poor in essential PUFA. Thus, a defatting process is commonly applied to generate a premium quality insect protein meal. The amino acid composition of BSF is more stable, well balanced, highly digestible and meeting the requirements of most fish and crustacean species. The protein fraction of BSF, and of dipteran species in general, is similar to fishmeal and better balanced than soybean meal.

The nutritional quality of the insect proteins is well established. Feeding trials with various fish / crustacean species have confirmed that dietary insect meal inclusions do not impair the growth and performance. Actually, inclusions of insect protein in aquafeeds have proven to improve FCRs of giant water prawn or juvenile rainbow trout for instance. Obviously, the optimum dietary inclusion varies widely with the fish / crustacean species considered and its nutritional requirements. Academic research and commercial applications report the successful partial or complete substitution of fishmeal or soybean meal in formulated feeds for both carnivorous and omnivorous farmed species with up to 40% insect meal inclusion. Therefore, insect meals are undeniably suitable alternative feed ingredients for the aquaculture.

It should be highlighted that insect-derived products, in particular BSF meal, are highly palatable, which is a critical point for aquafeeds. Fast identification of the feed and good ingestion contribute to improved performance and reduced FCRs. It has been mentioned that BSF meal may equal krill meal or fishmeal in terms of palatability.

Besides, a significant interest is rising around the bioactive molecules that insects contain naturally and the nutraceutical benefits of insect meals.

Positive impacts on gut health through a modulation of the microbiota of Rainbow trout, Jian carp, Siberian sturgeon or Marron crayfish were associated to dietary insect chitin. The specific role of chitin in fish diets is still controversial and is related to its dietary level of inclusion; when included at low levels, it might act as prebiotic, immuno-stimulant and anti-inflammatory molecule in fish, while if included at high doses it might reduce fish growth and cause intestinal inflammation.

Insects are also a primary source of antimicrobial peptides (AMPs) and more than 50 putative active peptides have been identified in BSF larvae. AMPs are key components of the innate immune system of most animals and have a broad spectrum of activity against bacteria, fungi, some parasites and viruses. Studies on Pacific white shrimp, Atlantic salmon and yellow catfish suggest that insect AMPs may have enhanced the immunity and disease resistance of these species. Significantly better survival rates were also noticed.

Therefore, even at low inclusion, insect meals can promote fish and crustacean health and better performance thanks to their immunostimulant, antioxidant and antimicrobial properties. Specific formulations targeting high-values species such as sturgeons, shrimps or salmonids or special requirements juveniles or broodstock could benefit of premium insect meal’s functionalities.

The production of insect proteins is based on the concept of circular economy where low-value organic side-streams (from industry or agriculture) are converted into high value products (i.e. insect biomass and frass). Compared to conventional livestock, insect breeding process has a low carbon footprint as it requires less land and water and produces fewer greenhouse gases.

The low environmental impact and sustainability aspects are major arguments promoting the use of insect protein in aquaculture as an eco-friendly alternative to traditional and no longer sustainable plant-based proteins and fishmeal.

Insects are more often considered as pests than beneficial. It is therefore reasonable to wonder whether they are safe to be used as protein sources for farmed animals.

In North America (USA and Canada), it is allowed to use BSF larvae meal in aquaculture feeds. There is no mention of mealworm products yet.

Europe is renowned for being extremely cautious regarding the use of processed animal proteins (PAPs) in animal feed since the last episode of Bovine Spongiform Encephalopathy (BSE). Nevertheless, in 2017, the EU Commission has lifted the ban concerning the use of insect-derived proteins for aquaculture only [(EU)2017/893]. This regulation includes seven insect species, including both BSF and mealworm, and providing that the farmed insects are fed with safe authorised substrates (i.e plant-origin products, blood products and hydrolysed proteins or gelatine and collagen from non-ruminants, eggs, dietary products and fishmeal).

In other countries in Asia or Africa, there are no official restrictions in place and insects are traditionally fed to livestock and pets. However, with the exception of China, the main insect producing companies worldwide tend to follow the European regulations, in particular regarding the feedstocks used to farm insects.

These regulatory breakthroughs have triggered the global development of the insect farming industry. Since 2017, massive investments are being secured by companies farming BSF or mealworms on every continent with projects as big as 100,000 tons of insect protein a year. As of today, total investments amount to over USD1.2 millions and strategic partnership with feed producing and engineering companies are strengthening the development of the industry.

A significant scale-up is now essential to meet the demand of the aquafeed industry in terms of volumes but also in terms of quality consistency and price competitiveness compared to conventional sources of proteins and other alternatives. This remains one of the main challenges to tackle.

About Dr. Emilie DEVIC
Being one of the pioneers of the Black Soldier Fly industry, I have forged my expertise over the last 10 years through various projects globally (Indonesia, Ghana, Malaysia). With a background in agronomy and aquaculture, my professional commitments are driven by the current challenges of the aquafeed industry. I am now leading the R&D team at Entofood in Malaysia, allying job and passion and strengthening my commitments to sustainability.