Hepatic fatty acid and transcriptome profiles during the transition from vegetable- to fish oil-based diets in rainbow trout (Oncorhynchus mykiss)

Traditional aquafeeds contain high amount of fish oil that increase heart-healthy omega-3 fats in the rainbow trout fillet. Transition to more sustainable plant oils reduces fillet omega-3 content, but this can be combated by feeding a fish oil-rich finishing diet in the weeks prior to harvest. By analyzing the fat and gene expression profiles, this study determined that the liver exhibits a unique metabolic response that differs depending on the type of dietary oil that is being consumed. Transitioning to a finishing diet also appears to force the remodeling of liver tissue which may compromise its metabolic capacity. These findings suggest that a gradual transition to the finishing diet may be an optimal approach for improving aquaculture sustainability while maintaining high levels of omega-3 fatty acids in rainbow trout fillets.传统水产饲料含有高量的鱼油，能够增加彩虹鳟鱼片中的心脏健康型欧米伽-3脂肪酸。向更可持续的植物油过渡会降低鱼片中的欧米伽-3含量，但通过在收获前几周喂养富含鱼油的增重饲料，可以对此进行抵抗。通过分析脂肪和基因表达谱，本研究确定肝脏表现出独特的代谢反应，这种反应因所摄入的饲料油类型而异。过渡到增重饲料似乎还会迫使肝脏组织重塑，这可能会损害其代谢能力。这些发现表明，逐步过渡到增重饲料可能是提高水产养殖可持续性的最佳途径，同时保持彩虹鳟鱼片中的高欧米伽-3脂肪酸水平。