Nutritional Enhancement Of Long-Chain Omega-3 Fatty Acids In Tilapia (Oreochromis Honorum)

The health benefits of the long-chain omega-3 eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids that are obtained primarily from fish consumption are numerous. However, supplies of the small pelagic fish that are high in EPA and DHA and used in aquaculture feeds are diminishing, causing greater use of plant-based feeds that are low in EPA and DHA. Farm-raised tilapia can be grown on feeds that are low in fishmeal, EPA, and DHA, but low levels of these fatty acids in fillets undermine the health benefits of consuming fish. A six-month feeding study was conducted on tilapia (Oreochromis honorum) to test the effect of augmenting a plant-based feed with corn oil, dried Schizochytrium sp. algae that are rich in DHA, or fish oil. These three experimental feeds were compared with a commercial feed containing fishmeal. The average levels of EPA+DHA for all samples within a treatment were significantly higher in fish fed the feed supplemented with Schizochytrium sp. (185 mg/100 g) or the commercial feed (177 mg/100 g) than in fish fed the feed supplemented with fish oil (138 mg/100 g) or corn oil (120 mg/100 g). Thus, algae represent a sustainable source of long-chain omega-3 fatty acids that can raise levels of healthy fats in aquacultured tilapia fed plant-based diets. Growth was greatest in fish fed the commercial feed, likely due to the higher amount and better quality of protein.