Abstract
Feeding experiments were conducted to examine the possibility to utilize low or non fish meal diets for red sea bream, Pagrus major. In Expt. I, three low-fish meal (10% fish meal) and one non-fish meal diets were prepared to contain soy protein concentrate (SPC, a main ingredient), defatted soybean meal (SBM), corn gluten meal (CGM), meat meal (MM), and poultry feather meal (PFM) in different combinations, and fed to juvenile red sea bream weighing 27 g on average for 56 days. In Expt. II, adult fish with an initial body weight of around 550 g were fed the four experimental non-fish meal diets for 183 days.
Palatability of the experimental diets was not affected by dietary fish meal levels in both sizes of fish. In both the experiments, growth and feed gain ratio were the highest in fish fed the control fish meal diet and tended to decrease with reduction of the SPC content in the test diets. However, in Expt. II, these performances in fish on the non fish meal diet containing 40% SPC were comparable to those of the control. Supplemental effects of crystalline amino acids to low-fish meal diets on growth and feed performances were not observed in Expt. I. Moreover, hemochemical examination at the end of feeding revealed that both juvenile and adult fish kept in good health status.
Therefore, it was suggested that a combination of SPC, SBM, CGM, MM, and PFM can be effectively employed as alternate protein sources to develop low or non-fish meal diets if these ingredients were adequately incorporated.
