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 |
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| Authors: | OC Betiku FT Barrows C Ross WM Sealey |
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| Affiliation: | 1. USFWS, Bozeman Fish Technology Center, Bozeman, Montana, USA;2. USDA‐ARS, Trout Grains Project, Bozeman Fish Technology Center, Bozeman, Montana, USA;3. Department of Food Science and Human Nutrition, Washington State University, Pullman, Washington, USA |
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| Abstract: | This study investigated the effect of the replacement of fish oil (FO) with DHA‐Gold (DHA‐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?1 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 DHA‐G 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?1 DHA‐G were significantly larger and consumed more feed than fish‐fed 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 DHA‐G (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. |
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| Keywords: | aquaculture docosahexaenoic acid fatty acids fish oil plant oil rainbow trout |
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