Acronym NA
Category
Aquaculture
Title Edible-, slaughter- and health quality of exercised rainbow trout Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Richard Skott Rasmussen Coordinator email mail@aquareco.dk
Coordinator institution
DTU-AQUA - Technical University of Denmark; National Institute of Aquatic Resources (Denmark)
Institutions involved
AU - Aarhus University (Denmark) ,
NA - Not available (Australia) ,
DTU-FOOD - Technical University of Denmark; National Food Institute (Denmark) ,
Start year 2008 End year 2011 Funding (€) € 560,000 Website NA Summary In Danish aquaculture the production of rainbow trout (Oncorhynchus mykiss) in intensive, recirculating systems has increased over the years and this trend is expected to proceed. Intensive systems are characterised by their potential to apply relatively high water velocities. This can be of importance to fish farmers since earlier studies have shown water currents to stimulate fish growth. A large part of the growth potential of modern trout strains has, however, been exploited through breeding and this creates an uncertainty as to what extent and how modern trout strains respond to increased water velocities in terms of growth. Quality is also a significant parameter in that regard. Fast growth in intensive rearing systems may have implications on trout quality through increased propensities to stimulate lipid depositions in edible parts of the fish and in buccal cavities with concomitant effects on sensory parameters and slaughter yields. The aim of the project is to study how exercise of rainbow trout may influence their growth and quality. Through collaboration with external partners and internal collaboration in DTU Aqua that was stimulated through the research area "Individual Biology", numerous competences are involved in the research. The project addresses important aspects of muscle physiology, hormonal control, enzymatic activities, fatty acid metabolism, overall fish growth and industrial fish quality. More specifically, by use of different exercise levels, fish growth and feed and protein utilization is monitored by changes in weights and lengths of the fish, together with differences in feed intake. Growth rates are evaluated together with blood plasma content of IGF-1. Furthermore, measurements of plasma cortisol levels together with feed shares indicate the impact on fish welfare. Slaughter yields are determined under common production conditions in industry. Changes in chemical proximate composition of fillets are studied together with fatty acid profiles and the particular change in healthy n-3 fatty acids. Muscle fibre growth and other characteristics in the swimming musculature are studied by use of histological techniques involving light microscopy as well as electron microscopy. Changes in gene expression for mTOR (the mammalian target of rapamycin) are studied for their potential role in muscle fibre hypertrophic or hyperplastic growth and proteome analyses considering other key proteins of importance to both growth and quality are also undertaken. Changes in the calpastatin/calpain system measured as gene expression and/or electrophoretic are considered important for development of fillet texture, which is measured instrumentally. Fillet texture is additionally considered by a trained sensory panel focusing on taste, odours, texture characteristics and appearance of the fish fillets. The results obtained so far have proven positive with regards to the idea of applying exercise in the rearing of modern rainbow trout strains. Negative aspects only seem to manifest when strenuous exercise levels are applied. Exercise has the potential to stimulate overall growth and reduce size differences within a stock, which is supposedly owing to less aggression when feeding. Through several changes in muscle physiological components brought about by exercise the fillet texture may increase, giving further indications that fish welfare may be improved through its implementation in aquaculture.
(1) Identifying correlations between water velocities and growth responses in modern strains of rainbow trout; (2) Investigating to which extent various quality parameters are influenced by exercising rainbow trout; (3) Studying how several physiological parameters correlate with growth and quality parameters in exercised teleosts.
Keywords
Fish;
Growth rate;
Diets;
Recirculating systems;
Land-based aquaculture;
Fish quality;
Fish biology;
Genetic;
Trout;
Animal welfare;
Marine Region
76
Not associated to marine areas
0
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