2009 Volume 57 Issue 1 Pages 45-52
The efficacy of replacing dietary fish meal with soybean meal for juvenile F1, red sea bream, Pagrus major female×black sea bream, Acanthopagrus schlegeli male, was assayed by growth and digestive performances. The F1 in triplicate tanks were fed each of following four diets: 46% fish meal (F), 30% fish meal+20% soybean meal (S20), 15% fish meal+40% soybean meal (S40) and S40+2500 phytase units (PU) /kg diet (S40P) for 12 weeks. In F1, the diets S20 and S40P showed similar growth performance to that of F and S40, but S40 had significantly lower specific growth rate, feed conversion efficiency and energy efficiency as compared with F diet. The diet S40 also led lower nutrient and phosphorus retentions than other diets, while the dietary treatments did not alter carcass and liver proximate compositions. Moreover, diet S40P produced higher apparent nutrient and phosphorus digestibility than diet S40, resulting in lower phosphorus discharge into surrounding water mass. These results reveal that a suitable replacement level of dietary fish meal with soybean meal is recommended about 67% with the co-supplementation of phytase at/under 2500 PU/kg diet under the experimental conditions used here.
