Fishmeal (FM) is the main source of protein in fish diets, but its supply is stable. So, available plant protein sources could be used instead of FM in aquafeeds. These plants-source proteins may negatively affect feed intake and/or absorption of nutrients due to bad digestion. Therefore, the efficacy of a dietary exogenous enzymes mixture (Hostazyme X; HX) on growth performance, antioxidant capacity, and digestive enzymes in common carp, Cyprinus carpio, was assessed. Dietary HX was included in practical diets at levels of 0.0 (control), 0.1, 0.5, 1.0, and 2.0 g/kg diet. Fish (0.84 ± 0.003 g) were fed on the tested diets up to apparent satiation twice daily in triplicate groups for 8 weeks. The fish performance was significantly improved (P < 0.05) by increasing dietary HX up to 1.0 g/kg diet after which fish growth and feed intake were almost the same. Also, intestinal amylase, lipase, and protease significantly increased (P < 0.05) due to HX supplementation leading to increased feed intake and overall growth performance. Likewise, the antioxidant activity of common carp was stimulated by HX supplementation in a dose-related manner, where the activities of superoxide dismutase, catalase, and glutathione peroxidase were significantly higher (P < 0.05), while malondialdehyde value was significantly lower (P < 0.05) in HX-fed fish groups than those fed the control diet. In conclusion, dietary HX could be used as a feed supplement to confer better growth performance and health of common carp fry with an optimal level of 1.0 g/kg diet.

鱼粉（FM）是鱼饲料中蛋白质的主要来源，但其供应稳定。因此，可以在水产饲料中使用可用的植物蛋白来源代替FM。由于消化不良，这些植物来源的蛋白质可能会对饲料的摄入和/或营养吸收产生负面影响。因此，评估了膳食外源酶混合物（Hostazyme X； HX）对鲤鱼Cyprinus carpio的生长性能，抗氧化能力和消化酶的功效。实际饮食中饮食中的HX含量为0.0（对照），0.1、0.5、1.0和2.0 g / kg饮食。将鱼（0.84±0.003 g）以试验饮食饲喂，一式三份，每天两次，直至两次饱食为止，持续8周。鱼的性能显着提高（P <0.05），通过增加日粮HX达到1.0 g / kg日粮，之后鱼的生长和采食量几乎相同。另外， 由于添加HX ，肠淀粉酶，脂肪酶和蛋白酶也显着增加（P <0.05），从而导致饲料摄入量和总体生长性能提高。同样，添加HX可以剂量相关的方式刺激鲤鱼的抗氧化活性，其中超氧化物歧化酶，过氧化氢酶和谷胱甘肽过氧化物酶的活性显着较高（P  <0.05），而丙二醛值显着较低（P HX喂养的鱼群中的<0.05）高于对照饮食的那些。总之，日粮HX可以作为饲料添加剂，以1.0 g / kg的最佳日粮水平赋予鲤鱼更好的生长性能和健康。