Acronym QUMA
Category
Aquaculture
Title New tools for optimising quality and performance management for Atlantic salmon (Salmo salar L.) reared in cyclic environments 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 Eldar Asgard Bendiksen Coordinator email eldar.bendiksen@biomar.no
Coordinator institution
NA
Institutions involved
NA
Start year 2007 End year 2011 Funding (€) € 176,517 Website NA Summary The Atlantic salmon (Salmo salar L.) industry has increased considerably over the last decades. Maintaining control of the harvest quality has become increasingly important for successful farming operations and to obtain good relations to the processing industry and consumers. This project reports from two different long-term commercial scale feeding experiments and one shorter-term, small scale trial where the impact of several intrinsic and extrinsic factors important for maintaining flesh quality and fish performance were investigated. Different analytical methods, such as HPLC, histology, chemometrics, and RIA have been applied to explore the mechanism underpinning growth and flesh quality attributes of farmed salmon. The results of this project demonstrate that there are temporal differences in growth performance and development of flesh quality characteristics between 0+ and 1+ salmon. Season is an important factor that influences the two smolt types differently. Feed energy and feeding regimes (ration and meal frequency) can be used to control important flesh quality attributes, but growth or feed utilisation might be compromised. Reduced meal frequency seems to be the most promising tool to reduce fillet fat content and probably fillet gaping since this strategy did not compromise growth as experienced with leaner feed and reduced feeding ration. Moreover, firmer flesh texture and reduced liquid loss were effectively obtained by moderate reduced ration. Salmon is able to adapt to reduced feed energy by increasing its feed intake and hence maintain growth performance, although best feed utilisation and flesh colour seem to be obtained by feeding a high-energy diet. Plasma ghrelin seems to stimulate daily appetite, whereas leptin may have a role in regulation of energy homeostasis. However, neither ghrelin nor leptin seem to act as adiposity signals, nor correlate directly to flesh quality attributes in salmon, but more research is needed to confirm these findings. Collagen cross-links (hydroxylysyl pyridinoline, PYD) was revealed as the most important variable affecting fillet firmness (r2 = 0.28), while individual growth rate (TGC3) of the fish prior to slaughter seemes to have little impact. Muscle cellularity accounts for 10-16% of the variation in fillet firmness, and also explained 14-23% of flesh colour variation in harvest size salmon. In addition, several organoleptic attributes of cooked muscle, e.g. feed odour and flavour, bitter taste, juiciness, hardness, and sourness odour, were significantly affected by fillet fat content, and fillet fat correlated positively to pigmentation and colour in raw muscle. Further growth in aquaculture depends on successful replacement of marine fish resources as feed ingredients, without compromising growth performance and flesh quality. Salmon farming is still dependent of marine fish resources and the reliance of marine fish oil is considered the most limiting factor, which is supported by the present work. This project also demonstrates that fishmeal levels can be substantially reduced without compromising either growth performance or flesh quality characteristics in salmon. Moreover, increased use of fishery by-products show that salmon farming can be sustainable in terms of being a net producer of both marine oil and marine protein. Nutrient-based measures are suggested to be more valuable criteria for assessing feed sustainability compared to traditional weight-based (?fish in-fish out') calculations. In the present project, low fishmeal (10-20%) and fish oil (13-15%) feeds ensured adequate levels of the highly unsaturated omega-3 fatty acids, e.g. minimum 2 g per 100 g muscle (target level >1.5 g) and n-6 to n-3 ratio lower than 0.67 (target level).
The main objective was to study variations in key flesh quality attributes of farmed Atlantic salmon for improved management practices. Sub goals: (1) Explore the effects of feed, feeding regime, smolt type, and season on growth performance in salmon; (2) Investigate the effects of intrinsic (muscle cellularity, connective tissue, fat content) and extrinsic factors (feed, feeding regime, growth rate, smolt type, season) on flesh quality characteristics in salmon, and assess to what extend replacement of fishmeal and fish oil with alternative feed ingredients results in improved sustainability of salmon production via reducing the dependency of "raw" marine fish as feed ingredient; (3) Study the function of ghrelin and leptin hormones in relation to growth and flesh quality in salmon.
Keywords
Fish biology;
Diets;
Fish quality;
Salmon;
Fish;
Marine Region
41
Norwegian Sea (27.IIa)
1
Marine Region Map
