Quest for renewable fish feed ingredients making headway

Although the aquaculture industry is one of the fastest growing food production industries globally, the cost of fish feed continues to increase which could impact further expansion. Many fish feed diets require fish oil and fishmeal, the cost of which has risen over 300 percent in the last 10 years. Much of the fish oil and fishmeal used in animal feeds are produced from the harvest of small open-ocean fish, which must be carefully managed in order to maintain sustainability. Further expansion of global fish feed production will require exploration into new formulations or replacement of fish oil and fishmeal. Three feed companies have made great strides in developing feed formulations that reduce the need to harvest fish from the ocean in order to feed other fish. The companies presented their work at the 2016 BC Shellfish and Seafood Expo in June.

Fishmeal-free feed

In the 2015 Sustainability Reporting Benchmark report released by Seafood Intelligence. Skretting ranked at the top among salmon and salmon feed producers. Its fish feed, called Microbalance Flex, is claimed to greatly decrease the amount of fish oil and fishmeal in their salmonid diet without impacts to fish health and growth. Prior to the company’s research it was thought that formulations that consisted  less than 25 percent fishmeal would have detrimental physiological effects and have big impact on growth and feed conversion. With Microbalance Flex the company was able to reduce the fishmeal requirement to 5-10 percent, allowing it to increase feed production while decreasing its dependence on wild fish products. Furthermore, in 2015 trials, Skretting succeeded in removing the fishmeal completely; the resulting feed did not have detrimental effects on fish health or growth.

Fly larvae as feed component

Rather than reducing the fish oil and fishmeal component of feed, other companies have gone a different route when it comes to fish feed development. Enterra began exploring the possibility of replacing fishmeal and fish oil with a more sustainable ingredient, while addressing the problem of global food waste. Realizing that many wild fish species survive at least partially on insects, they have begun the production of black soldier fly larvae using pre-consumer food waste. Once the larvae are cooked and dried, trials have shown they make an excellent replacement of both fish oil and fishmeal for animal feed production. Additionally, the frass produced by the insects can be processed to make a certified organic fertilizer that can be marketed and sold to farmers. So far they are capable of producing 100 tonnes per day but have a large area for future expansion as demand increases for their products.

Camelina oil

Another replacement for fish oil that is being explored is an oilseed crop called Camelina sativa. Some feed companies have managed to replace some of the fish oil in their diets with canola oil and soy. However, the fatty acid profiles of both of those oils differ significantly to that of fish oil and replacing too much has been shown to reduce fish survival and growth while decreasing the nutritional profile of the fish. Camelina oil, on the other hand, has an Omega-3 and Omega-6 profile much closer to that of fish and can be grown sustainably in many parts of the US and Canada. Trials in which salmon were fed a camelina-oil-based diet produced fish with the same Omega-3/Omega-6 ratio in the muscle tissue as salmon that were fed fish oil. Comparatively, fish fed with canola-oil-based diet resulted in a much lower Omega-3/Omega-6 ratio. Many feed producers are watching closely the development and trials of feed containing the ingredient.

— Amanda Bibby