Replacing Fish Oil with Hydrogenated Soybean Oils in Feeds for Yellowtail

Abstract

To assess the relative merits of monounsaturated fatty acid (MUFA)-rich versus saturated fatty acid (SFA)-rich lipids as alternatives to fish oil in aquafeeds, diets formulated for Yellowtail Seriola dorsalis-containing menhaden fish oil, fully hydrogenated soybean oil (high SFA content), partially hydrogenated soybean oil (high MUFA content), or blends of these soy-derived lipids (20/80, 40/60, 60/40, or 80/20)-were tested in a 7-week feeding trial. Juvenile fish (~11 g) were stocked in a semi-closed recirculating aquaculture system (15 fish/tank), diets were randomly assigned to tanks in triplicate (N = 3), and fish were fed in slight excess of estimated apparent satiation. Growth performance did not vary based on dietary SFA versus MUFA content, but performance was inferior among fish fed the soybean oil-based feeds relative to those fed the fish oil-based feed: weight gain was 714-770% versus 848%; specific growth rate was 4.03-4.16% versus 4.32% body weight/d; and feed conversion ratio was 1.30-1.38 versus 1.27. Generally, fillet fatty acid composition mirrored dietary composition except that the fillets of fish fed diets containing primarily fully hydrogenated soybean oil contained fewer SFAs and more long-chain polyunsaturated fatty acids (LC-PUFAs) than one would expect based on dietary fatty acid profiles. Fillets of fish that were fed partially hydrogenated soybean oil contained trans-fatty acids (0.02-0.06 g of trans fats per 100 g of fillet) but only at trace levels. Liver fatty acid profiles were less affected by dietary lipid source, but where differences existed, they followed patterns similar to those observed in fillets. Results suggest that blends of fully and partially hydrogenated soybean oils may yield slightly higher growth performance and fillet lipid content without accumulating enough trans fats to negatively affect consumers. Diets containing only fully hydrogenated soybean oil may slightly reduce lipid digestion in Yellowtail, but they mitigate LC-PUFA loss associated with fish oil sparing.

Trophic Levels Predict the Nutritional Essentiality of Polyunsaturated Fatty Acids in Fish—Introduction to a Special Section and a Brief Synthesis

“…Additionally, diet-to-tissue transfer of 22:6n-3 is enhanced among Cobia fed SFA-based feeds (Woitel et al 2014a(Woitel et al , 2014b. Based on these data and other recent findings from our group (Trushenski and Kanczuzewski 2013;Trushenski et al 2013aTrushenski et al , 2015Rombenso et al 2015Rombenso et al , 2016aRombenso et al , 2016bRombenso et al , 2017Rombenso et al , 2018Bowzer et al 2016;Emery et al 2016;Bergman and Trushenski 2018;Mata-Sotres et al 2018) it seems likely that LC-PUFA nutritional requirements could be met at lower dietary inclusion rates if the required fatty acids are provided in the context of SFA-rich alternative lipids.…”

Fatty Acid Signatures in Different Tissues of Mediterranean Yellowtail, Seriola dumerili (Risso, 1810), Fed Diets Containing Different Levels of Vegetable and Fish Oils

“…Specifically, in wild and farmed Mediterranean yellowtail, the FA composition has been analysed in the muscles, liver, ovary [10,11,50,59,60], and eggs [61]. Other studies have been performed in other Seriola species, such as S. lalandi [47,62,63], S. quinqueradiata [64,65], S. dorsalis (Gill, 1863) [66,67], and S. rivoliana [45], which mainly focused on the FA composition of muscle tissues.…”

The status of California yellowtail Seriola dorsalis as a commercially ready species for marine U.S. aquaculture

“…The reduction of fishmeal and fish oil in the diet of juvenile CYT (like other Seriola) is an important research topic that has been studied for many years. A full replacement diet has yet to be developed that can economically compare to the existing commercial diets, but this species can be grown on reduced fish meal and fish oil diets (Bergman, Trushenski, & Drawbridge, 2017a;Bergman, Trushenski, & Drawbridge, 2017b;Buentello, Jirsa, Barrows, & Drawbridge, 2015;Jirsa, Davis, Stuart, & Drawbridge, 2011;Jirsa, Rombenso, Page, Drawbridge, & Trushenski, 2014;Rombenso, Trushenski, & Drawbridge, 2018;Rombenso, Trushenski, Jirsa, & Drawbridge, 2016;Stuart et al, 2021;Trushenski, Rombenso, Page, Jirsa, & Drawbridge, 2015). Beyond juvenile nutrition, research is still needed to optimize intensive RAS systems for land-based CYT juvenile production tackling topics such as efficient oxygen utilization, testing of novel biofiltration media, and understanding critical density and water quality thresholds.…”