Optimizing dietary nutrients for improving salmon pigmentation

Offentlig prosjektsammendrag

In this project we will explore nutrient ingredients that influence the pigmentations of the salmon. The synthetic astaxanthin is an efficient antioxidant within feed and fish but the use of astaxanthin for coloring of the flesh is the main function. Recent changes in the legislation with the exclusion of use of the synthetic antioxidant ethoxyquin in the salmon feed have resulted in an new mix of antioxidant within the feed. In addition to a more challenged farming situation with more physical handling of the fish, this together have put an constrain on the astaxanthin pigment in the feed and fish. Therefore understanding how some specific ingredients influence on the feed and flesh pigment level is of high importance. In this project we will focus on pigment product type, oil types and vitamins which are influencing positive or negative on color in commercial grower feed for Atlantic salmon. Within the oil composition there is knowledge that phospholipids are particular involved in fat metabolism and pigment gut uptake. The long-chain polyunsaturated fatty acids (LC-PUFA) with the eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids have shown to be an positive contributor to color but little is known in relation to omega-6 (n-6) levels and pigment. Better knowledge about nutrient color enhancing effects will lead to better sustainable use of pigment resources and stabilize our Mowi salmon color.