Abstract
A feeding experiment was conducted to evaluate the nutritional value of malt protein flour (MPF) in diets for fingerling carp Cyprinus carpio. In the control diet, white fish meal (WFM) was used as the sole protein source to provide approximately 35% crude protein. In the test diets, the WFM protein in the control diet was isonitrogenously replaced by; (1) MPF at the 20, 40, and 60% levels; (2) a combination of MPF and defatted soybean meal (SBM) at the 40 and 60% levels; (3) MPF supplemented with crystalline essential amino acids (EAA) at the 60% level; and (4) extruded MPF at the 60% level. These diets were fed to satiation to fingerling carp with an initial mean weight of 5.5g for 6 weeks at 26°C.
The fish fed the diets with the 20 and 40% MPF substitution levels, and the 60% MPF level supplemented with EAA, showed good growth, feed efficiency, and retention of dietary protein, and the values of these parameters were not significantly different from those of the control group. Moreover, the weight gains of the fish fed the diets containing both MPF and SBM at the 40and 60% replacement levels were significantly higher than that of the control group.
These findings suggest that the use of MPF in combination with SBM is more effective as a substitution of fish meal in fingerling carp diets than is either MPF alone or MPF supplemented with crystalline EAA.
