Abstract
Fish oil (FO) is widely used in aquaculture feed due to its high levels of long‐chain omega‐3 fatty acids. But increasing cost, limited supply, and sustainability concerns have led to the search for alternative omega‐3 sources. Bioengineered (BE) oilseeds, such as docosahexaenoic acid (DHA) canola (Brassica napus, OECD Unique Identifier: NS‐B5ØØ27‐4, branded Aquaterra), offer a scalable, land‐based source of DHA and other long‐chain omega‐3 fatty acids. This study evaluated the efficacy of DHA canola oil (DCO, Aquaterra), as a replacement for FO in the diet of Pacific white shrimp (Penaeus vannamei). Five isonitrogenous, isolipidic, and isocaloric diets were formulated by replacing FO with graded levels of DCO (0%, 25%, 50%, 75%, and 100%). Postlarval shrimp (initial weight 0.7–0.8 g) were stocked in a recirculating saltwater system (30 ppt) comprised of 40 aquaria (eight tanks for each diet), and shrimp were fed four times daily for 11 weeks. Results showed no significant differences in growth performance or survival across different dietary groups. Feed intake was reduced at 100% FO replacement, but feed conversion ratio (FCR) and energy retention improved. Whole‐body protein and energy remained stable across all dietary groups, while lipid retention increased with DCO‐fed groups. Whole‐body amino acid and fatty acid compositions were influenced by DCO inclusion, with the 50% replacement group exhibiting comparable composition to that of the 100% FO group, especially in terms of the high content of total omega‐3 fatty acids. For growth, DCO can replace up to 100% FO in shrimp diets; however, 75% DCO replacement is recommended when considering the whole‐body fatty acid profile and n−3/n−6 ratio. Based on the present findings, 50%–75% FO replacement with DCO in shrimp diets can be considered optimal, supporting its use as a robust and viable lipid source for commercial shrimp aquaculture.