Fish Meal Replacement in Chum Salmon (Oncorhynchus keta) Diet With Alternative Protein Sources

Chum salmon (Oncorhynchus keta) is an indigenous salmonid species found in Korea. This experiment was conducted to evaluate the effects of fish meal (FM) replacement with krill meal (KM), soy protein concentrate (SPC), meat meal (MM), and chicken byproduct meal (CBM) in chum salmon diets. A control diet was designed to contain 60% FM, 5% KM, and 8% SPC (FM60). Three diets were formulated to contain 45%, 30%, and 15% FM (FM45, FM30, and FM15). The reduced protein levels after FM replacement were supplied with a mixture of KM, SPC, MM, and CBM. Fish, averaging 5.94 ± 0.19 g, were fed four experimental diets or a commercial diet (COMF) for 6 weeks. Final body weight of fish fed FM30 and FM15 diets were significantly increased than fish fed COMF. Feed intake (FI) was significantly higher in FM60, FM45, and FM30 groups than COMF group. Condition factor (CF) was significantly higher in FM15 group compared to FM60 and COMF groups. Muscle saturated, highly unsaturated, and omega-3 fatty acids were significantly higher in COMF group compared to those of fish fed other diets. FM15 groups exhibited significantly lower EPA and DHA levels compared to FM60, FM45, and FM30 groups and significantly higher omega-6 levels compared to other groups. The results indicate that a mixture of KM, SPC, MM, and CBM can be used to replace FM in chum salmon diet down to 30%-15% while maintaining normal performance compared to diet containing 60% FM.