Nutrition as a mean to reduce sea lice infestation in Atlantic salmon

Summary

Aller Aqua Norway have in collaboration with Biofeed developed an ingredient (BF) that dissolved in sea water appears to in-activate adult sea lice (in vitro model, Ilab). Trials at the Aller Aqua R&D-licenses have shown that BF-feeds to rainbow trout appear to reduce lice number, while this effect is not observed in Atlantic salmon. Funding from FHF was therefore given to further develop the ingredient to target a feed that also can reduce lice numbers in Atlantic salmon. Aller Aqua Norway has been the project leader and provided design and ingredients for the experiments. Spring 2018 an ingredient provided by Biofeed was chosen due to its in-activation of adult lice. The ingredients were provided to Nofima June 2018 to be included in feeds for trial in tanks at Ilab and sea cages at Sematech. However, analysis of feed and fish after the trials showed high value of iodine (1200 mg/kg) due to inclusion of components in the Biofeed ingredients. The iodine content in the control feed was 7 mg/kg. Nonetheless the experiments provided interesting results (e.g. reduced lice number and altered skin morphology/physiology) that are discussed in the report, and could be basis for further research on the nutritional impact on skin health and sea lice in Atlantic salmon and rainbow trout.