Title: Optimal protein ratio for the growth of farmed Arctic charr (Salvelinus alpinus)

Final project
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Supervisors: Olafur Sigurgeirsson
Arctic charr (Salvelinus alpinus); feeding; fish meal and oil reduction in fish feed formulation; optimal protein ratio; growth.


A study was carried out to determine the optimal protein and fat ratio for growth of farmed juvenile through to table sized Arctic charr (Salvelinus alpinus) in the northwest of Iceland in land based facilities between October 2007 and February 2008. The objective was to determine the effects of varying protein and oil ratios on the growth of juvenile to table sized Arctic charr. In order to attain this objective the specific growth rate (SGR), condition factor (K), feed conversion ratio (FCR), digestibility and chemical composition of the fed fish after every 4-5 weeks were determined. The fish were fed on six different dietary compositions which had an inclusion of celite marker at 1% and protein to fat compositions of 29% to 28.5%, 33% to 26.5%, 37% to 25.3%, 41% to 24%, 45% to 22.8% and 49% to 21.6% respectively. The diet comprised of capelin fishmeal, wheat, colour, ash and capelin fish oil.

The charr were also raised in two different conditions, one group was treated to saline water of 17o/oo salinity (start feed size: 250-/+40 g) and the other group was raised in fresh water (size: 230-/+10 g). Findings indicated that no significant difference occurred in growth while varying the protein and oil ratios. This is very important due to the fact that the study sought to find a way of reducing the protein and oil from fish thereby reducing production costs and increasing profits for the fish farmers while also taking into consideration the ethical implications of the use of trash fish to formulate fishmeal.

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