Improving aquaculture productivity by meeting dietary omega-3 and omega-6 requirements of Atlantic salmon

Ian Carr, Veramaris®

Veramaris® recently published their Optimum Omega Nutrition™ White Paper, a science-based paper that provides feed guidelines to help salmon farmers, together with their feed suppliers, re-set feed specifications for long-chain omega-3 polyunsaturated fatty acids with the objective of improving the performance and profitability of their fish farming operations.

Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (ARA) are essential fatty acids (EFA) that play a critical role in ensuring optimum fish health, welfare, performance and product quality in Atlantic salmon aquaculture. The omega-3 fatty acids, EPA and DHA, are in particularly short supply with annual production from marine fisheries being extremely limited and unlikely to show any marked increase over time.

EPA and DHA play a key role in the physiological development of fish, as well as in anti-inflammatory response, wound healing and disease resistance. Therefore, specific levels for each of these EFAs should be included in feed formulations, as is already usual practice for nutrients like vitamins and amino acids.

Over the past 15 years, EPA & DHA omega-3 levels in salmon feed have been declining. However, recently leading producers of Atlantic salmon in Norway have been increasing dietary levels of EPA & DHA omega-3, seizing the opportunity to restore their levels in feed to those when salmon diets were comprised of fishmeal and fish oil as the main sources of protein and fat. In other parts of the world, such as The Faroe Islands, farmers have long recognized the importance of EPA & DHA omega-3 in supporting the biological performance of salmon and its potential to drive differentiation in the market.

Alternatives to fish oil exist such as vegetable oils, however, these oils are very different to fish oils as they are typically deficient in EPA & DHA omega-3, but high in omega-6 which when oversupplied can negatively impact fish health, welfare, product quality and productivity. Additionally, low dietary levels of EPA & DHA omega-3 are known to change the omega-3 content of salmon fillets, impacting the “high in omega3” attribute of salmon, which must be protected for consumer health benefits as well as the continuing success of the salmon farming sector.

Veramaris® natural marine algal oil is a sustainable and consistent alternative source of EPA, DHA, and ARA with a profile that is superior to other sources of omega-3 including highly concentrated fish oil. It enables precise feed formulation and effectively supports Atlantic salmon production. Optimum Omega Nutrition™ by Veramaris® (Fig. 1) is a guideline for meeting EPA & DHA omega-3 and ARA omega-6 requirements, while maintaining the correct omega-3 to omega-6 ratio in salmon diets, leading to improved salmon health and welfare throughout production. By using Veramaris® natural marine algal oil in conjunction with the Optimum Omega Nutrition™ guidelines, fish farmers not only stand to improve productivity, product quality and yield but also lower their marine footprint.

It is intended that salmon farmers will use the new Optimum Omega Nutrition™ white paper to recognize and then act upon the great opportunity they have to

Figure 1. Optimum Omega Nutrition™ Infographic. Starting in the middle of the illustration, Veramaris® based the Optimum Omega Nutrition™ protocol around the lifecycle of the salmon. The blue bars show how the EPA & DHA requirements are higher for salmon when they are held under more challenging farm conditions. And while the requirement for EPA & DHA reduces through the lifecycle of the fish, it never falls below 10% of total fatty acids. But it’s not enough only to focus on total EPA plus DHA levels. The ratio of EPA:DHA also has to be adjusted through the lifecycle, ending with a ratio of 1.5:1 after 400 g until harvest for best performance. This is because of the important functional role that EPA plays in supporting immune responses as the first line of defense (especially for mediating inflammatory responses). And because of the pro-inflammatory nature of omega-6 fatty acids (such as linoleic acid), the ratio of Omega-3:Omega-6 should also be maintained at 3:1.

optimize the health and welfare of their fish through setting the amount and types of essential fatty acids in their feed. Veramaris® natural marine algal oil enables them to “take control” of their omega nutrition in ways that were not possible just a few years ago. This action helps ensure further sustainable production growth, while protecting the reputation of salmon farming and upholding the brand promise of farmed salmon as a healthy, sustainable and nutritious food, rich in omega-3. References available on request.

More information: Ian Carr

Global Business Development Director Veramaris® E: ian.carr@veramaris.com