Effect of Aspergillus niger Fermented Soybean Meal Supplementation in Formulated Diets on Growth Performances in Juvenile Asian Seabass (Lates culcarifer Bloch)

Abstract

The utilization of indigenous mold Aspergillus niger from aquaculture areas to improve the quality of soybean meal (SM) by fermentation and replacement in Asian seabass diet was studied on growth performances and feed utilization in juvenile Asian seabass, Lates calcalifer. Sinking diets with 40 % of protein were formulated. The main sources of protein in the diets were from fish meal (FM). Low substitution levels of 4 % of protein from SM, 10 % of total protein, were used in diets D1 - D4 with replacement of fermented soybean meal (FSM) at 0, 25, 75, and 100 %, respectively, and high substitution levels of 8 % of protein from SM, 20 %of total protein, were used in diets D5 - D8 with replacement of FSM at 0, 25, 75, and 100 %, respectively. Initial weight of juvenile Asian seabass was 12.83 - 12.90 g. 10 fish were stocked in 100 L glass tanks with triplicate groups. Each diet was fed to apparent satiation twice daily for 10 weeks. The results presented that the final body weight (BW), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and feed capital showed significant difference (P < 0.05) while final total length (TL), survival rate (SR), carcass percentage, and hepatosomatic index (HSI) did not show significant difference (P > 0.05). The 4 % of protein from SM was able to be replaced by 25 - 100 % of FSM with increased growth performances and feed utilization, while feed cost (Thai baht kg-1 of fish) was reduced, respectively. The A. niger FSM is alternative protein source for growth, feed utilization improvement, and feed cost reduction of Asian seabass farmers.