The effect of feed pigment type on flesh pigment deposition and colour in farmed Atlantic salmon, Salmo salar L.

The characteristic pink colour of salmonid flesh is a result of deposition of naturally occurring carotenoid pigments. Achieving successful pigmentati on in farmed salmonids is a vital aspect of fish farming and commercial fee d production. Currently commercial diets for farmed salmonids contain eithe r or both of the synthetic pigments commercially available, astaxanthin and canthaxanthin. Atlantic salmon, Salmo salar L. ( = 220 g initial weight) w ere given feeds where the pigment source was astaxanthin only, canthaxanthi n only or a astaxanthin/canthaxanthin mix. The rearing environment was 12 x 3 m tanks supplied with sea water at the EWOS research farm Lonningdal, ne ar Bergen, Norway. As the proportion of dietary canthaxanthin increased, fl esh pigment levels also showed an increase; the pigment content in the musc le of canthaxanthin-only fed fish was 0.4 mg kg(-1) (or 14%) higher than th at of the astaxanthin-only fed fish, with the mixed pigment fed fish being intermediate between the two extremes. Results of cross-section assessment for Minolta colorimeter redness (a*) values and Roche Salmofan(TM) scores a lso showed an increase in colour with increasing proportions of canthaxanth in in the feed. The data reported clearly indicates that S. salar ( = 810 g final weight) of this size deposit canthaxanthin more efficiently than the y do astaxanthin. These results contrast with those obtained by other autho rs with rainbow trout, Oncorynchus mykiss (Walbaum), and imply that the abs orption or utilization of the pigments differs between species.