Traditional and Modified Soy Oils as Substitutes for Fish Oil in Feeds for Hybrid Striped Bass

Abstract

AbstractIn order to assess the relative merits of different soy oils as alternatives to fish oil, we evaluated the production performance and fillet fatty acid profiles of hybrid Striped Bass fed feeds containing fish oil (FO) or 50:50 blends of fish oil and standard (STD SO), saturated fatty acid‐enriched (SFA SO), low alpha‐linolenic acid (LOW ALA SO), or hydrogenated (HYD SO) soy oil for 12 weeks (4 tanks/diet, 8 fish/tank; initial weight = 67.8 ± 0.2 g, grand mean ± SE). Weight gain (214 ± 5%) and specific growth rate (1.4 ± 0.0% body weight/d) were unaffected by diet. Although some differences were observed for feed conversion ratio, none of the soy‐fed groups were significantly different from the FO‐fed group (1.2 ± 0.0). Feeding the soy diets altered fillet fatty acid composition, but coefficient of distance values indicated the SFA SO (Djh = 3.9) and HYD SO (Djh = 9.1) feeds yielded fillet fatty acid profiles that were more similar to the FO control than the STD SO (Djh = 17.3) and LOW ALA SO (Djh = 17.6) feeds. All of the soy oils assessed were acceptable as partial substitutes for fish oil in hybrid Striped Bass feeds in terms of production performance; however, SFA SO appears more suitable for maintaining fillet fatty acid profile.