The effect of total replacement of fish oil with DHA-Gold® and plant oils on growth and fillet quality of rainbow trout (Oncorhynchus mykiss) fed a plant-based diet

Authors

• O. C. Betiku, USFWS
• F. T. Barrows, USDA-ARSFollow
• C. Ross, Washington State University
• W. M. Sealey, USFWSFollow

Date of this Version

2016

Citation

Aquaculture Nutrition (2016) 22; pp. 158-169. doi: 10.1111/anu.12234

Comments

U. S. government work.

Abstract

This study investigated the effect of the replacement of fish oil (FO) with DRA-Gold (DRA-G)-supplemented plant oils (PO) in rainbow trout fed plant-protein-based diets. Five diets (450 mg g^-1 digestible protein and 150 mg g-I crude lipid) were fed to rainbow trout (initial weight 37 ± 0.5 g) for 12 weeks in a 15°C recirculating water system. The lipid inclusion types and levels were FO, PO and PO with DRAG supplemented at 30 mg g^-1, 60 mg g^-1 or 90 mg g^-1 of the diet replacement for corn oil. Fish fed 90 mg g-I DRA-G were significantly larger and consumed more feed than fishfed PO or FO (218 g and 2.6% bwd-1 versus 181 g and 2.4% and 190 g and 2.3%, respectively). Feed conversion ratio was significantly increased in fish fed 90 mg g^-1 DHAG (0.99) as compared to fish-fed FO (0.90) and 30 mg g^-1 DHA-G (0.91). Panellists found trout fillets from fish fed the 90 mg g^-1 DHA-G diet to have significantly fishier aroma and flavour than fish fed the FO diet. Fatty acid analysis demonstrated that 60 mg g^-1 or 90 mg g^-1 DHA-G supplementation increased PO fed fish fillet DHA to fatty acid levels equivalent or higher than those fish fed a FO diet.