The use of vegetable oils in aquaculture diets represents a key strategy to promote more sustainable production, although its application entails metabolic and digestive challenges, especially during juvenile stages. This study evaluated two novel lipid blends, A and B, formulations based on vegetable oils, bioactive lipids, antioxidants, and phospholipids, designed to enhance growth and nutrient utilization in juvenile coho salmon (Oncorhynchus kisutch). Over a 12-week trial, six diets were evaluated: 100% fish oil (FO), a 50:50 blend of canola oil and FO (FO+CO), A (FA) and B (FB) as the exclusive lipid sources, and their respective 50:50 blends with FO (FO+A and FO+B).
Compared to FO+CO, commonly used in commercial diets, treatment blends significantly improved growth. The A formulation achieved the highest final weight (13.5% higher) and SGR (5.6% higher), while FO+A with 8% and 1.7% increases, respectively. FB and FO+B also enhanced growth performance, with final weights 9.4% and 10.8% higher than FO+CO, respectively. These improvements were accompanied by SGR increases of 3.5–4.2% and feed conversion ratio (FCR) reductions of up to 5.0%. EPA+DHA tissue levels. Although full FO replacement lowered EPA+DHA (4.13–4.47% of total fatty acids), growth was unaffected, suggesting improved lipid utilization.
We will present the effectiveness of two novel lipid blends as partial and complete FO substitutes by examining their effects on intestinal morphology, lipid metabolism, and overall performance, in comparison with standard market diets based on FO and CO.
Keywords: Plant-based lipids, coho salmon, growth performance, fish oil reduction, sustainable aquaculture, smoltification.