Why choose farmed over wild fish?
Do salmon and trout feeds contain colouring?
The pink colour of salmon flesh, wild or farmed, results from the retention of carotenoids in the fish flesh. Astaxanthin is a naturally occurring carotenoid and is the major carotenoid naturally found in wild salmon and crustaceans (prawn, lobsters) and is responsible for their pink-red pigmentation.
Pigments are biological substances that impart colour to the tissues of organisms. Carotenoids are classed as pigments. Carotenoids are naturally present in the diet of most animals. Astaxanthin is an essential nutrient for salmon; salmon require it to remain healthy and disease free. Astaxanthin supports good reproduction and skin health in salmon. Salmon cannot make their own astaxanthin, they consume it via their diet. The wild salmon diet includes krill, zooplankton, small fish and crustaceans all of which naturally contain astaxanthin.
The main source of astaxanthin used by the aquaculture industry is synthesized, yielding a molecule that is identical to that found in nature. There is no difference between the two (natural vs synthetic) in terms of how they impact fish growth performance or final quality as the natural and synthetic version share an identical chemical structure. In terms of their manufacture as feed ingredients they can be sourced from yeast, algae and bacteria or via chemical synthesis. Astaxanthin is made in the same way as for vitamins that you might purchase from a health food shop.
