Analysis of the competitiveness of the eel aquaculture industries in Taiwan and China

Abstract

A feeding trial was conducted outdoor in concrete tanks stocked with fingerling black carp (Mylopharyngodon piceus) for 8 weeks to investigate whether commercial defatted soybean (Glycine max merrill) meal or lupin (Lupinus angustifolius) meal could be used as a partial replacement for white fish meal in a practical diet with 40% crude protein. The white fish meal diet without any legume seed meal was used as the control. Four diets were formulated by replacing 15 and 30% white fish meal with either soybean meal or lupin meal based on iso-nitrogen and iso-energy. Additional two diets, in which 30% of the fish meal replaced with either legume seed meals, were supplemented with lysine and methionine to study the efficacy of adding limiting amino acids. No mortality occurred in all tanks. Weight gain, feed efficiency, protein efficiency ratio and productive protein value were not significantly (p>0.05) different among the treatments. Fish fed the control diet had the lowest body lipid and highest moisture contents. Fish fed soybean meal containing diets had higher liver lipid content than fish fed lupin meal containing diets. Fish fed the control diet had higher hematocrit value than fish fed soybean meal containing diets. Fish fed 30% soybean meal diet had lower whole body zinc contents than fish fed the control diet. Both whole body and plasma calcium, phosphorus and magnesium contents in fish were not affected by the treatments. These results suggest that practical diets formulated upon iso-nitrogen and iso-energy white fish meal can be replaced with up to 30% soybean meal or lupin meal without methionine and lysine supplementation for black carp.