The control diet contained all Danish L T-fish meal as protein sources. The other experimental diets contained 2.2, 5.6, 8.9 and 11.1% PPC respectively. Diet 6 contained 5.6% PPC and 1.7% methionine.

• 对照饲料全部以鱼粉为蛋白源，其它饲料分别含土豆蛋白2.；2%25，5