Effect of lipid and colorants in feed on growth and quality of Icelandic Arctic charr

• Main Authors: Sigurgeirsson, Olafur Ingi, Arnason, Jon, Kristjansson, Gunnar Orn
• Format: Article in Journal/Newspaper
• Language: English
• Published: Zenodo 2020
• Subjects: Lipid sources; Lipid content; Colorants; Coloring regimes; Nutrient composition; Filet colour; Arctic charr
• Online Access: https://doi.org/10.5281/zenodo.4293753

This study mainly aimed at researching dietary effects on growth and important quality characteristics of Arctic charr, lipid composition and flesh color. The first object of this study was to investigate the effect of different lipid sources and lipid ratio in diets on growth and chemical composition in fillets. The second object was to investigate the effect of different colorant sources in diets and colorant feeding combinations on flesh color in fillets. Two long-term experimental trials (1= 250 days; 2=268 days) were run in saline water (approx. 12-18ppt) with initial weight of fish above 100+g in both trials. The water temperature was in the range of 6-9°C in the first but 8,5-10,5°C in the second trial. 1. Different dietary lipid ratio and lipid sources did not affect the fish growth, growth rate, feed consumption, FCR or harvesting output. The dietary lipid content and composition was reflected by lipid content in fillets. The fatty acid composition in the diets was reflected fatty acid composition of the fillets. The most important difference was in the content of the long chain n-3 and n-6 fatty acids and n-3/n-6 fatty acid ratio between groups fed fish oil or mix of plant oil sources. Lipid source or volume in diets only had minimal effects on other nutritional components analysed in fillets. The different dietary lipid sources and ratio was considered to have rather small effect on visual fillet color, although some existing variation related to analytical methods. 2. Analysis of carotenoids in the experimental diets showed difficulties in producing diets containing exact carotenoid content, according to plan and formulation, regardless of colorant types. The feed processing, lack of stability of the sensitive carotenoids or inaccurate content description of the colorant sources led to varying recovery of estimated concentration in the diets. Therefor the feeding and regimes needed to be adjusted by mixing daily ration with uncolored diets. Consumed colorants were calculated according to diet color ...