Effects of The β-Carotene on the Growth Performance and Skin Pigmentation of Rainbow Trout (Oncorhynchus mykiss, W. 1792)

Abstract

In this study, the effect of dietary supplementation of β-carotene (beta carotene) on growth and skin pigmentation of rainbow trout. Fish were fed with diets containing 30 and 70 mg β-carotene kg -1 , and without supplemented basal diet for 12 weeks. Weight gain (WG), specific growth rate (SGR) and survival rate (SUR) in the C group was significantly lower (p<0.05) than beta carotene supplemented diet groups. Feed concervation ratio (FCR) in the C was significantly lower (p<0.05) than β-carotene supplemented diet groups. But PER of fish did not differ among the diet groups (p>0.05). Crude protein value of fish meat was higher in beta-carotene supplemented diet groups (p<0.05) than control diet group. But, crude lipid and ash were not statistically different among the groups (p>0.05). The lowest carotenoid concentration levels in the lateral and tail regions of the fishes in the experimental groups have been obtained in the C (control) group (lateral region: 0.263 ± 0.021 ug/g; tail ragion: 0.009 ± 0.002 ug/g) while the highest cumulative values have been determined in the fishes of β70 groups (lateral region: 0.643 ± 0.46 ug/g; tail region: 0.124 ± 0.015 µg/g).