Nutrient Requirements

The traditional use of fishmeal and fish oil in aquafeeds ensured that all nutrient requirements were largely met but the unavoidable switch to non-marine ingredients has brought the need to reassess requirements sharply into focus, as highlighted by the US Academies of Science National Research Council Committee, which included Prof Douglas Tocher of the Nutrition Group, in their 2011 report on the “Nutrient Requirements of Fish and Shrimp”. Surprisingly, few species have had their nutrient requirements properly determined empirically, and the move to more sustainable feeds largely based on plant meals and oils with very different nutrient profiles has necessitated a much greater emphasis of nutritional requirements. Thus, the Nutrition Group are currently major partners in an €8 million pan-European EU Framework Programme 7 initiative entitled “Aquaculture feeds and fish nutrition: paving the way to the development of efficient and tailored sustainable feeds for European farmed fish” or ARRAINA for short. The project involves 21 partners, including 10 research institutes/universities and 9 industrial/SME partners spanning 11 European countries.

A primary aim of ARRAINA is to investigate novel methods for determining nutritional requirements and, following an extensive review of existing knowledge, it is focussing on the establishment of the quantitative requirements for nutrients (with particular emphasis on micronutrients and vitamins, throughout the life cycle) that are lacking in key species including Atlantic salmon, rainbow trout, gilthead sea bream, European sea bass and common carp, and on the evaluation of the nutritional value of alternative feeds. Another main objective is to determine the long-term effects of alternative aquaculture feeds on fish metabolism, performance and quality, including threshold effects of dietary components, carry-over from maternal diets to larvae, the use of feed additives to supply sufficient levels of essential trace elements and vitamins, antagonistic interactions between nutrients that alter dietary requirements, and antagonistic effects of undesirable components linked to novel feed ingredients. The underpinning basic science is being investigated using targeted integrative tools (including meta-analysis of existing data) that can accurately measure and predict metabolic and health effects and explore how nutritional interventions with alternative feeds and differences in nutritional experience at critical life stages could affect fish development, health and resistance to diseases, growth performance, fat deposition and metabolism, as well as flesh quality and food safety. The ARRAINA project will therefore provide flexibility in the use of various ingredients in the formulation of feeds which are cost-efficient, environmentally friendly, and which ensure production of seafood of high nutritional value.