Growth Performance of Sub-Market Size Yellow Croaker Weaned from Fresh Fish to an Extruded, Soymeal-Based Feed
Region: Northeast AsiaDownload
Sub-market size yellow croaker (Pseudosciaena crocea) were weaned from a fresh fish diet to an extruded pellet feed and grown to market size in cages in ASA feeding trials at Nanji Island, Wenzhou, and Xiangshan, Ningbo. The extruded feed was a soymeal-based ration containing 43% crude protein and 12% fat and fed in extruded, floating pellet form. Yellow croaker were stocked in 22.5-m3 cages at 31 fish per m3 in the Wenzhou trial, and at 75 fish per m3 in 8-m3 cages in the Ningbo trial. In the Wenzhou trial, yellow croaker grew from 164 g to 327 g in 123 days on the extruded feed, with an FRC of 1.67:1 and 96.7% survival. Net income for the Wenzhou trial was RMB 7,043 per cage, or RMB 313/m3 for the 22.5-m3 cages. ROI was 83.2%. In the Ningbo trial, yellow croaker grew from 103 g to 248g in 118 days on the extruded feed, with an FRC of 2.24:1 and 93.3% survival. Net income for the Ningbo trial was RMB 3,480 per cage, or RMB 435/m3 for the 8-m3 cages. ROI was 72%. Fish growth and FCR in the Ningbo trial were affected by a parasitic infestation midway through the trial. Both trials demonstrated good croaker growth performance and economic return with the soymeal-based, extruded feed. High net income and ROI demonstrated the feasibility of weaning sub-market size yellow croaker from fresh fish to an extruded feed and growing them to market size on the extruded feed. The added benefits of quality consistency, less nutrient loading of the aquatic environment, ease in shipping and storing, and absence of potential pathogens make extruded feed a superior choice than fresh fish for feeding yellow croaker in cages.