Protein is the most expensive nutrient in aquafeed. Cottonseed meal can be used as an important source of plant protein in aquafeed because of its low price and high yield. Concentrated dephenolized cottonseed protein (CDCP) is a promising alternative source of fish meal obtained by processing cottonseed meal to remove gossypol. In this study, an 8-week feeding experiment was conducted to evaluate the effects of replacing fishmeal by CDCP on growth performance, intestinal histomorphology, body composition, hematological and antioxidant parameters of Oncorhynchus mykiss. Six isonitrogenous (43 %) and isolipid (14 %) experimental diets were formulated to replace 0% (D1), 10 % (D2), 20 % (D3), 30 % (D4), 40 % (D5), 50 % (D6) of fish meal by a corresponding amount of CDCP. The results indicated that the replacement of 10 %–50 % fish meal by CDCP had no adverse effect on the growth, feed utilization and survival rate of O. mykiss. The whole-body and muscle composition and hematological parameters of O. mykiss have not changed due to the replacement of 10 %–50 % of fish meal by CDCP. No significant pathological changes in the mid-gut was observed among all experimental groups. The length of villus was not affected by the substitution of fish meal with CDCP. There was no significant difference on the activity of SOD and T-AOC in fish fed with different diets. However, the MDA contents of fish fed the D1- D3 diets were significantly higher than that of fish fed the D4-D6 diets. In conclusion, there was no adverse effect on growth performance, intestinal histomorphology, body composition, hematological and antioxidant parameters of O. mykiss by replacing 10 %–50 % fish meal with concentrated dephenolized cottonseed protein. The antioxidant capacity of O. mykiss was improved by replacing 30 %–50 % fish meal with CDCP. CDCP is a suitable protein source for O. mykiss.

蛋白质是水产饲料中最昂贵的营养素。棉籽粕价格低，产量高，因此可以用作水产饲料中植物蛋白的重要来源。浓缩的脱酚棉籽蛋白（CDCP）是通过加工棉籽粉去除棉酚而获得的有前途的鱼粉替代来源。在这项研究中，8周饲养试验以评估生长性能，肠组织形态学，身体组成，血液学和抗氧化参数由CDCP代替鱼粉的效果虹鳟。配制了六种等氮（43％）和等脂（14％）实验日粮来代替0％（D1），10％（D2），20％（D3），30％（D4），40％（D5），50％ （D6）鱼粉中加入相应量的CDCP。结果表明，置换CDCP 10％-50％鱼粉对生长，饲料利用率和生存率无不良影响O.虹鳟。米氏曲霉的全身和肌肉组成及血液学参数由于CDCP替代了10％–50％的鱼粉，因此未改变。在所有实验组中，中肠均未观察到明显的病理变化。绒毛长度不受CDCP替代鱼粉的影响。不同日粮喂养的鱼中SOD和T-AOC的活性没有显着差异。但是，饲喂D1-D3日粮的鱼的MDA含量显着高于饲喂D4-D6日粮的鱼的MDA含量。总之，有生长性能，肠组织形态学，身体组成，血液学和抗氧化参数没有不利影响O.虹鳟通过用浓dephenolized棉籽蛋白代替10％-50％鱼粉。米氏猕猴桃的抗氧化能力通过用CDCP代替30％–50％的鱼粉改善了这种情况。CDCP为合适的蛋白质源O.虹鳟。