Growth Performance of Japanese Sea Bass Fed Extruded Feed and Fresh Fish Rations in A Cage Trial at Ningbo, China
Category Aquaculture Saltwater Sea Bass
Region Northeast Asia
Japanese sea bass (Lateolabrax japonicus) growth in cages was evaluated from fingerling to sub-market size with extruded pellet and fresh fish rations in an ASA feeding trial at Xiangshan, Ningbo along the coast of Zhejiang Province, China. The extruded feed was a soymeal-based ration containing 43% crude protein and 12% fat and fed in extruded, floating pellet form. Fresh fish was fed in chopped form. Sea bass fingerlings were stocked in 8.0-m3 cages at 200 fish per m3. Sea bass grew from 10.6 g to 178.3 g in 102 days on the ASA extruded feed, with an FRC of 1.82:1, and from 11.0 g to 178.3 g in 102 days on the fresh fish ration, with an FCR of 6.78:1. Gross production averaged 31 kg/m3 with the extruded feed and 29.6 kg/m3 with the fresh fish ration. Net income and ROI were RMB 478/m3 and 62.7%, respectively, for sea bass fed the extruded ASA feed, and RMB 341/m3 and 40.4% for sea bass fed the fresh fish diet. Feed cost per kilogram of fish growth was RMB 9.46 with the ASA feed and RMB 14.92 with the fresh fish diet. Results demonstrated a 40% higher net income, 55% higher ROI, and 37% lower feed cost with the soymeal-based extruded feed than with a traditional fresh fish diet. The added benefits of quality consistency, less nutrient loading of the aquatic environment, ease in shipping and storing, and absence of potential pathogens make manufactured feed a better choice than fresh fish for feeding Japanese sea bass.