In the present study, rainbow trout fingerlings, Oncorhynchus mykiss, were fed diets supplemented with 0% (C), 0.5 (T1), 1.5 (T2), 2.5 (T3), and 4% (T4) mistletoe extract (ME), Viscum album over eight weeks. At the end of feeding trial, growth performance, serum antioxidant and innate immune responses, and serum bactericidal activity against Aeromonas hydrophila were evaluated. According to results, the highest final wight and wight gain (%), and the lowest feed conversion ratio (FCR) were observed in T2 and T3 treatments. Regression analysis showed that fish growth parameters were polynomially-related to dietary ME levels. The optimum dietary ME level, based upon the varied growth parameters, was 1.78 to 1.94%. The highest moisture content was observed in the control group followed by the T1 treatment, whereas the highest protein contents were observed in the T2 and T3 treatments. The lipid and ash contents were not affected by ME supplementation. Serum lysozyme, ACH50, total Ig, SOD, and bactericidal activity significantly increased in the ME-fed fish, with the highest values observed within the T3 treatment. The highest CAT and GPx values were recorded in the T2 and T3 treatments. ME treatment significantly decreased serum MDA levels, which was lowest in the T3 treatment. Serum ALT activities were similar in the T2, T3, and T4 treatments, and were significantly lower than those of T1 and control (C) treatments. Serum AST and ALP activities exhibited declines along with an increase in dietary ME levels; in which the lowest activities were occurred in the T4 treatment. In conclusion, dietary ME supplementation proved beneficial to rainbow trout, as it stimulated its growth performance, innate immune and antioxidant systems, and promoted bactericidal activity. Moreover, serum hepatic health indicators suggest that dietary ME may improve the fishes' hepatic health.

在本研究中，虹鳟鱼鱼种Oncorhynchus mykiss的饮食中添加了0％（C），0.5（T1），1.5（T2），2.5（T3）和4％（T4）槲寄生提取物（ME），超过8周的Viscum专辑。饲喂试验结束时，其生长性能，血清抗氧化剂和先天免疫应答以及血清对嗜水气单胞菌的杀菌活性被评估。根据结果​​，在T2和T3处理中观察到最高的最终增重和增重（％），以及最低的饲料转化率（FCR）。回归分析表明，鱼的生长参数与膳食中的ME水平呈多项式相关。根据不同的生长参数，最佳的饮食代谢能水平为1.78％至1.94％。对照组中最高的水分含量，随后是T1处理，而在T2和T3处理中，蛋白质含量最高。补充ME不会影响脂质和灰分含量。用ME喂养的鱼的血清溶菌酶，ACH50，总Ig，SOD和杀菌活性显着增加，在T3处理中观察到最高值。在T2和T3处理中记录到最高的CAT和GPx值。ME治疗显着降低了血清MDA水平，这在T3治疗中最低。在T2，T3和T4治疗中，血清ALT活性相似，并且显着低于T1和对照（C）治疗。血清AST和ALP活性随着饮食中ME水平的升高而下降。在T4处理中活性最低。总之，事实证明，膳食补充剂对虹鳟鱼有益，因为它刺激了虹鳟鱼的生长性能，先天免疫和抗氧化系统，并增强了杀菌活性。此外，血清肝脏健康指标表明，饮食中的ME可以改善鱼类的肝脏健康。并显着低于T1和对照（C）处理。血清AST和ALP活性随着饮食中ME水平的升高而下降。在T4处理中活性最低。总之，事实证明，膳食补充剂对虹鳟鱼有益，因为它刺激了虹鳟鱼的生长性能，先天免疫和抗氧化系统，并增强了杀菌活性。此外，血清肝脏健康指标表明，饮食中的ME可以改善鱼类的肝脏健康。并显着低于T1和对照（C）处理。血清AST和ALP活性随着饮食中ME水平的升高而下降。在T4处理中活性最低。总之，膳食ME补充剂被证明对虹鳟鱼有益，因为它刺激了虹鳟鱼的生长性能，先天免疫和抗氧化系统，并增强了杀菌活性。此外，血清肝脏健康指标表明，饮食中的ME可以改善鱼类的肝脏健康。因为它刺激了生长性能，先天免疫和抗氧化系统，并增强了杀菌活性。此外，血清肝脏健康指标表明，饮食中的ME可以改善鱼类的肝脏健康。因为它刺激了生长性能，先天免疫和抗氧化系统，并增强了杀菌活性。此外，血清肝脏健康指标表明，饮食中的ME可以改善鱼类的肝脏健康。