Effects of replacement of fishmeal with other alternative protein sources in the feed on hydrochemical parameters and flesh quality of rainbow trout (Oncorhynchus mykiss)

Abstract. The rainbow trout is preferred for cultivation in Bulgaria due to the high rate of growth and its meat quality. The aim of this study was to track the substitution of fishmeal and fish oil with alternative sources of protein and lipids. The results obtained after substitution with such protein sources – soya worm flour, oil seeds – were controversial. The aim of the experiment was to replace fishmeal and fish oil with an alternative – Ω-3 – FORPLUS algea (Alltech Neogreen®). The hydrochemical and growth parameters were examined, along with the chemical composition of meat during the cultivation of rainbow trout in a recirculating system. Each tested fodder was cultivated in four tanks. The experiment continued for 60 days. The substitution of fishmeal and oil did not influence the hydrochemical parameters. The replacement with – Ω-3 – FORPLUS algea did not lower the growth indicators of the rainbow trout. Fishmeal and fish oil replacement did not exert a negative effect on the chemical composition of the meat.