Effects of different dietary amino acid patterns on growth performance and body composition of juvenile giant croaker Nibea japonica

A feeding trial was conducted to investigate the effects of different dietary amino acid patterns on growth performance, feed utilization and body composition of juvenile Nibea japonica. Four semi‐purified diets were formulated to simulate the dietary amino acid profiles of juvenile giant croaker whole body protein (GCP), Peru fishmeal protein (PFP), red sea bream eggs protein (REP) and soybean meal protein (SMP) by supplementing with pre‐coated crystalline amino acids (CAA). A control diet contained only intact protein sources provided by the fishmeal and casein (2:1). Each experimental diet was fed to satiated triplicate groups of juveniles (10.73 ± 0.07 g) twice a day for 8 weeks. The highest weight gain (WG) was observed in the juveniles fed the control diet, whereas no significant differences were found between the juveniles fed the GCP and control diets. Fish fed the control, GCP, PFP and SMP diets did not exhibit any significant difference in protein efficiency ratio (PER), feed conversion (FCR) or nitrogen (N) retention. The results of this study suggest that the amino acid (AA) patterns of juvenile whole body protein could be used as a guideline in the formulation of dry diets, which also confirms that the juvenile giant croaker is able to utilize high amounts (20%) of CAA in coated form for growth.