The Effects of Dietary Supplement of Rounded Brittle Fern Weed (Laurencia obtusa) (Hudson) (J.V.Lamouroux, 1813) as a Natural Carotenoid on Pigmentation in Rainbow Trout (Oncorhynchus mykiss)

Abstract

The aim of this study was to determine the effects of Laurencia obtusa (Hudson)as a natural carotenoid on the growth performance, biochemical composition and skinand fillet pigmentation in rainbow trout (Oncorhynchus mykiss).Laurencia obtusa was collected manually from the shores of Sinop (The BlackSea-Turkey) and included in the diet at two different ratios as 30 (L30) and 60 (L60)mg/kg diet. The fish with an average weight of 248.9±6.1 g were fed by theexperimental diets for 6 weeks.The best growth performance was determined in L0. The differences betweenprotein, fat and ash values of fish were not significant (P>0.05). At the end of thestudy, the L* value was highest in the L0 group (59.94±1.28) and lowest in the L60group (53.43±1.98) and, in fillet, it decreased in all experimental groups compared tothe initial values (P0.05). The b* valueincreased in all groups in skin (P0.05).