Oslo, October, 2024: A newly released study conducted at ILAB (Stiftelsen Industrilaboratoriet) in Bergen, Norway, in collaboration with Aker BioMarine, QuantiDoc AS, and the Dept. of Biosciences at the University of Bergen, evaluated the effects of a krill meal diet on skin health and reduction of sea lice in Atlantic salmon.
The study concluded that krill meal (8%) inclusion exhibited positive effects on the mucosal (skin) health and was effective in reducing the number of sea lice in Atlantic salmon smolts.
Poor skin health and the prevalence of sea lice present a significant challenge in the salmon industry today. Current treatments and handling can lead to increased fish mortality and reduced growth, which impact profitability and compromise fish welfare. This situation highlights the urgent need for fish-sensitive control measures, including functional nutrition, supplemented with functional ingredients such as Antarctic krill in the fish feeds.
“We started with the hypothesis that a functional diet with krill meal could influence the skin mucosal health in the salmon smolts, which would help them cope the sea lice infestation. Krill meal offers a range of high-quality nutrients that we believed could be effective in boosting the robustness of the salmon skin barrier, which would enable them to better cope with lice infestation, and so we put this theory to the test at our facility in Bergen,” says Susanne Håvardstun Eide, Research Coordinator, ILAB.
Krill meal tested as dietary solution to sea lice challenge
Krill meal is a well-known source of high-quality nutrients, including well balanced amino acid profile, phospholipids, omega-3 fatty acids, and other valuable micronutrients. However, nothing has been published on the effects of krill meal on the mucosal barriers and sea lice infestation in salmon, until now.
The 86-day feeding trial was conducted in six 500L tanks at ILAB’s Bergen-based facility. Each tank contained 50 Atlantic salmon smolts. During the first eight weeks of the trial, the salmon received one of two test diets (krill meal 8% or krill meal 12%) or a control diet mimicking a conventional salmon feed. After this initial feeding period, the fish were challenged for two weeks with sea lice infestation, while maintaining the test diets.
Key results following the salmon skin mucosal health and sea lice challenge
- Skin mucosal response after 8 weeks of feeding and pre-sea lice challenge: The 8% krill meal group exhibited significant improvement in skin mucosal health measured on the parameters of skin mucous cell size, volumetric density, and increase in defense activity.
- Sea lice reduction results: The 8% krill meal group had the statistically significantly lowest number of sea lice in comparison to the two other groups.
“This is the first study of its kind to indicate the potential of krill meal as part of a functional nutrition strategy for enhancing skin health and reducing sea lice in Atlantic salmon says Karin Pittman, Professor Dept. of Biosciences Univ. of Bergen and CSO - Quantidoc AS . Based on this study and our previous trials, we can confidently recommend an inclusion of 8 to 10% krill meal for small developmental stages, whereas for bigger grower and pre-slaughter salmon, an inclusion level of 10 to 12% would be beneficial,” says Kiranpreet Kaur, Director R&D Fish Health and Nutrition, Aker BioMarine.