Novel Omega-3 Sources in Feeds and Impacts on Salmon Health

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

We will investigate whether novel omega-3 oils supplying de novo eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) will impact the health of fish fed these oils. Our contention is that these new dietary oils will have effects on lipid and fatty acid metabolism of fish that will, in turn, modulate production of crucial lipid mediators affecting inflammatory responses and immune functions with consequent impacts on resistance to pathogens and parasites. To test this hypothesis, a feeding trial with Atlantic salmon (Salmo salar) will investigate four novel omega-3 oils from macroalgae and genetically-modified oilseed (Camelina sativa) crops supplying DHA alone, EPA alone, or combinations of EPA+DHA, in comparison with traditional fish oils as reference feeds, and omega-3-rich krill oil and omega-6-rich sunflower oil as positive and negative health controls, respectively. Salmon in both freshwater and seawater phases will be subjected to specific pathogen challenges including Aeromonas samonicida, sea lice and amoebic gill disease. The project will provide detailed data on the influence of the novel omega-3 oils on lipid class and fatty acid composition of salmon tissues, and determine the consequences this has on critical metabolic and immune pathways. The insight that these data will provide will, in turn, enable us to elucidate the impact the novel omega-3 oils have on the production of lipid mediators that are crucial in mediating the molecular, mechanisms involved in the inflammatory responses and immune function. The results will enable us to define the positive and negative impacts of novel omega-3 oils on salmon health and welfare, and provide definitive advice on the use of these oils as feed ingredients for farmed salmon.

Outcomes will impact at many levels including the salmon feed and production industries, consumers and the general public, in addition to academia. Primary exploitation will be through development and production of novel sustainable feed formulations utilising entirely new de novo sources of the omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), EPA and DHA, as replacements for the dwindling and expensive marine ingredients, fishmeal and especially fish oil, currently used in UK aquafeeds. The project will therefore provide industry with a new strategy with huge potential to improve the nutritional quality of farmed fish and, in turn, the economic viability and sustainability of UK aquaculture. Tangible outcomes will be the development of more sustainable feeds formulated with very low marine ingredients, but without the negative impacts on n-3 LC-PUFA levels in farmed salmon, expandable to all sectors of the aquaculture industry. However, our exploitation strategy will be far wider than just the feed sector, as we will target fish production industries as a whole, and increase awareness of the potential of new ingredients supplying high levels of EPA and/or DHA to mitigate fish health and product quality issues currently associated with existing sustainable feed formulations.
There are two main beneficiaries, the UK salmonid farming, and aquaculture feed industries. The aquafeed industry itself will play a key central role in the commercial application and uptake of the omega-3 sources with our industrial project partner, BioMar taking a lead role. All partners, Universities of Stirling (UoS), Aberdeen (UoA), Highlands and Islands (UHI) and Rothamsted Research (RRES) have worked extensively with BioMar for more than a decade, collaborating on several research studies including BBSRC IPA, BBSRC-NERC and BBSRC Super Follow-on-Funding projects, and PhD CASE studentships. Moreover, UoS and UoA have long established histories as centres of excellence for fish nutrition and health research and are recognised as trusted sources of independent research. All four partners have extensive links with all sectors and key stakeholders in the UK aquaculture industry that involve regular direct contact, engagement and discussion. Thus, we will use these well-established links, along with the support of the industry-led Scottish Aquaculture Innovation Centre (SAIC), to engage with potential end-users including major fish farming companies, to ensure industry-wide dissemination and engagement.
Currently, all partners have joint projects with industrial partners at all levels of the industry and these direct links are ideal for a two-way flow of information, and actively involving and engaging end users, stakeholders and beneficiaries, seeking their input throughout the project. UoS, UoA and UHI membership of ARCH-UK (BBSRC-NERC aquaculture Research Hub-UK) involves both Government and HEIs, knowledge will be rapidly disseminated to relevant stakeholders and used to develop further collaborations and strategic initiatives. Tocher and Martin lead ARCH-UK Working Group 1 on finfish nutrition. Communication of issues relating to human health, such as farmed fish and dietary omega-3 will be effected through existing contacts directly in Government (e.g. Food Standards Agency, the Scottish Executive and UK Government), and through various pan-Governmental food security initiatives that we are involved with. Results will be published as usual in scientific peer-reviewed literature (conference proceedings and papers in high impact journals), but also disseminated widely to industry through contributions to trade and professional magazine articles and online sites such as FISHupdate, and the public via Institutional web pages and social media, as well as mainstream media articles and interviews in local and national press.