Title: Salmon bioassay for evaluation of fishmeal performance
Author: Dr. Laura Martinez Rubio
Background: Although the fishmeal content in typical feeds for salmon farmers has decreased dramatically since the 1990s, fishmeal is still of strategic importance to the industry. This is based on the fact that fishmeal contributes to the consistency of salmon performance and is a valuable contributor to salmon health and quality. In addition, fishmeal still represents a large portion of feed in specialty products, including starter feeds and fish feeds that serve specialty markets, including the organic and Label Rouge segments. Although in vitro testing provides insight into the quality of fishmeal, there remains a need for some in vivo testing, as it provides insight into the combined effect of all quality criteria that is not yet fully consolidated by the in vitro data alone. In this project, we used a salmon bioassay to examine the quality of four common types of fish meal, using salmon performance, feed digestibility and gut health as key performance indicators (KPIs). Click here to view the PDF.
Title: Do Yeast Hydrolysate and Supplementary Marine Phospholipids Work as Aids to Total Fishmeal Replacement in Feeds for Atlantic Salmon, Salmo salar, in the Seawater Production Phase?
Authors: Mia Berwick and Edward King
Background: Numerous explanations have been proposed for the inconsistent performance of fishmeal-free feeds, and both the micro and macronutrient content of fishmeal have been exhaustively replicated in attempts to produce consistently performing fishmeal-free salmon feeds. Part of the nature of fishmeal is that it is a source of both small peptides and phospholipids that, while not considered essential nutrients, can be important components that a fishmeal-free feed must still provide. In this project, we evaluated the impact of supplementing fishmeal-free feeds with hydrolyzed yeast and marine phospholipids compared to feeds containing different amounts of fishmeal. Click here to view the PDF.
Title: Does addition of an organic acid to the diet improve intestinal health and growth performance of Atlantic salmon(Salmo salar) at the production stage with seawater?
Author: Martin Røed
Background: Organic acids synthesized by the gut flora of salmon are associated with improved cellular integrity/function and are therefore beneficial for fish health. Production of organic acid by the gut flora can be stimulated by providing nutrients and conditions that alter or nourish the gut flora, such as by administering prebiotics. An alternative approach is to apply organic acids directly to the feed with the expectation that they will act directly on the target tissues of the gut. In this project, we evaluated the potential of an organic acid supplement to improve gut health of salmon and thereby improve growth and feed utilization. An additional component of the project was to evaluate the role played by the degree to which plant protein ingredients are refined and how the application of an organic acid might promote similar gut health outcomes. Click here to view the PDF.
Title: Comparison of two functional feeding strategies for optimizing the health of Atlantic salmon in light of typical, real-world challenges to gill and skin integrity
Author: Martin Røed
Background: Farmed salmon live in an environment rich in challenges to fish health, and a significant portion of the total cost of salmon farming is related to maintaining fish health and overall resilience. One strategy to improve the health and well-being of farmed salmon is to increase their robustness through the use of functional ingredients (FIs). Functional ingredients are non-medicinal components in the feed that can be classical nutrients, such as vitamin E, or nutritional supplements, such as purified yeast cell wall components, whose consumption is associated with improved health, well-being or quality. In this study, we are tracking changes in skin and gill tissue over an extended period of time in salmon fed a feed containing either a seasonally adjusted, multi-purpose FI package or a feed containing an FI package specifically targeting gill and skin health. Click here to view the PDF.
Title: Evaluation of whole and hulled field beans, Vicia faba, as a feed for Atlantic salmon, Salmo salar, in seawater
Authors: Mia Berwick and Dr. Guido Riesen
Background: Field beans (also known as horse beans or faba beans) are rich in both starch and protein and are an economical feed material for use in high nutrient salmon diets. Because they are widely produced throughout Europe and create value as part of a crop rotation system, they represent an opportunity to provide more locally grown, sustainable protein in feeds for European farmed salmon. Shelling (removal of the outer pericarp and seed coat) is a process that can simultaneously increase the starch and protein content and reduce the crude fiber and antinutrient content of the beans. Depending on the yield and cost of shelling, this increases their value in formulation, but access to shelling facilities adds further complications and/or costs in the supply chain. In this project, we evaluated the usefulness of both whole and hulled field beans as feed ingredients for salmon using a wide range of performance, health and quality indicators. PDF available soon.
Title: Influence of dietary digestible protein content and pellet size on growth performance of large Atlantic salmon, Salmo salar
Author: Dr. Guido Riesen
Background: It is known that the level of digestible protein (DP) in the diet is an important factor in the growth performance of Atlantic salmon and that lower DP levels in the diet than required will reduce growth performance. On the other hand, DP levels above the requirements for optimal growth increase feed costs, reduce profitability and negatively affect the sustainability of salmon farms. Changes in environmental and husbandry conditions and improved growth through stock selection are some of the factors that necessitate periodic reassessment of salmon DP requirements. In addition, for fully fed animals, pellet size does not necessarily determine salmon performance, but is an important factor in feeding efficiency, which in turn can affect growth and the feed conversion ratio (FCR) actually achieved in the field. This project provided an opportunity to simultaneously reassess digestible protein requirements and evaluate the impact of pellet size on salmon performance in a semi-commercial setting. Click here to view the PDF.
