Fish meal and fish oil have long been staple ingredients in aquafeeds – serving as dependable sources of nutrition for developing fish. But over several years, the supply of these ingredients has grown increasingly limited, reaching peak scarcity in 2023 upon the cancellation of the anchovy fishing season in Peru.
As a result, the high cost and lack of availability of fish-based ingredients have created an almost untenable feed situation for nutrition-seeking aquaculture producers. Alternatives are needed, now.
“It’s a situation that has created more urgency around the search for alternative feed ingredients,” says Marianne Nergård, Product Director, Aker BioMarine. “The aquaculture industry is motivated to find efficient and sustainable novel ingredients that enable them to reduce or replace fish meal and fish oil in their feeds. This has pushed ingredients such as krill meal and other alternatives into the spotlight…and into the feed.”
The unique composition of krill meal makes it a stand-out aquafeed ingredient
The exploration of alternative ingredients is not exactly a new endeavor, as the industry has seen the writing on the wall (or at least on their balance sheet) warning them that scarcity comes at a high cost.
Alternatives such as soy, peas and other legumes have found their way into aquafeeds over the years, serving as viable sources of protein, and soybean meal has moved up the rankings as the most used protein source in aquafeeds globally. Also, vegetable oils have been introduced in an increasing proportion of the diets.
But replacing the fishmeal and fish oil is not as simple as inserting vegetable ingredients into the feed. The resulting feed may lose the unique taste and smell that marine ingredients provide, attributes that are known to trigger appetite and feed uptake.
In addition, marine ingredients deliver a powerful blend of proteins, lipids, vitamins, antioxidants, and minerals that are key to a thriving supply of livestock, and the replacements of these important nutrients may have variable efficiency in the animal. One of the known effects of reducing the marine ingredients is the reduction in fish robustness that has been linked to the reduced amount of omega-3 fatty acids DHA and EPA in primarily vegetable-based feeds.
“Aquafeeds of the future will consist of less fish meal and fish oil, and a more mixed composition of sustainable raw materials. The introduction of all these new raw materials requires a lot of knowledge about the influence this has on the feeds, in terms of nutrient effectiveness, interactions, palatability, and the effect on health and welfare. Krill meal and krill oil are well-documented ingredients that may play an important role in supporting good appetite and robustness, which has shown to potentially be threatened when marine ingredients are left out of the feed equation,” adds Nergård.
Krill meal is a natural source of many of the important nutrients in both fish oil and fish meal, and the nutrients are highly available for utilization by the fish. Just like fish meal, krill meal and krill oil also trigger the urge to consume more of the feed. And the more the fish eat, the more nutritional value they may extract and absorb – resulting in bigger and healthier fish, and better outcomes for producers.
Palatability is key to the utilization of sustainable feeds
An important factor influencing the aquaculture industry is the growing importance of sustainability. Demand for farmed fish products is on the rise, and with the expected population growth in the coming decades, the dependency on aquaculture to feed the world will lead to multifold industry growth.
But ramping up production cannot come at the cost of the environment. The feed is responsible for the largest environmental impact in fish farming, and the raw materials are the most important part of the footprint of the feed. This puts the source of the aquafeed ingredients under the microscope, and producers must be able to stand behind the feed they choose and know that it is sourced in a sustainable and responsible way.
The trend now is that the industry is accessing more sustainable raw materials. And hopefully, there is much more to come. But it is important to always keep in mind that one may have the most sustainable aquafeed in the world, but if the fish won’t consume it, it becomes worthless.
Krill meal and krill oil are strong enhancers of taste and flavor and have the added advantage of a powerful nutritional composition. Adding krill into the formulation may enable the utilization of sustainable feeds that wouldn’t necessarily work without them. It also helps that the krill fishery happens to be one of the most sustainable fisheries in the world, according to the Sustainable Fisheries Partnership.
“Sustainable ingredients need to fit into a package that in the end is both highly nutritious and supports palatability. And it’s here that krill stands apart from many other ingredients, as a part of the feed it serves several roles as it is sustainable, incredibly tasty and provides several key nutrients to the feed ” says Ragnhild Dragøy, VP Product Management and Sustainability, Aker BioMarine.
A feed is only as good as its ingredients
There are many factors that make up the overall success of the aquafeed. According to an article highlighting the importance of the ingredients and their attributes “A feed is still only as good as its ingredients”, published in Aquaculture Nutrition in 2020, producers can’t look at only one of the positive attributes of a raw material at a time.
The author proposed a 7-step approach to succeeding with new ingredients: “Step 1 Characterization, Step 2 Palatability, Step, 3 Digestibility, Step 4 Utilization, Step 5 Immunological effects, Step 6 Processing Effects and Step 7 Product Quality Influences. Once these seven steps have been achieved, a formulator can make the appropriate choice as to whether to use any particular ingredient and with what constraints to impose on their use” (Glencross 2020).
We believe adding krill into a feed with the new ingredients may help fulfill several of these steps, allowing the raw material providers to move into ramping up production even faster.
“What we see, study after study, is that even at low levels of krill oil inclusion, the benefits to the farmed animals are plentiful –better growth performance, more robust fish and improved product quality. This is a sustainable marine ingredient that the industry can count on," adds Dragøy.
The content and graphs in this article are extracted from this source:
Glencross, B. (2020). A feed is still only as good as its ingredients: An update on the nutritional research strategies for the optimal evaluation of ingredients for aquaculture feeds. Aquaculture Nutrition, 26 (6), 1871–1883. https://doi.org/10.1111/anu.13138.