The supplementary effects of an emulsifier mixture (polyoxyethylene (20) sorbitan monolaurate and distilled monoglycerides) were investigated on feed utilization, growth performance, and immunity of olive flounder, Paralichthys olivaceus, replacing fish oil with beef tallow. A fish oil containing diet was considered as positive control (PC) and a diet containing beef tallow instead of fish oil was considered as negative control (TW). Two other diets (EM01 and EM02) were prepared by adding 0.01 and 0.02% of the emulsifier into the TW diet. After 8 weeks of a feeding trial, growth performance and feed utilization were significantly higher in fish fed EM01, EM02, or PC diets compared to those fed the TW diet. Dry matter digestibility was higher in EM01 and EM02 diets than the TW diet and comparable to PC diet. Lipid digestibility was significantly higher in PC diet compared to TW diet. Liver EPA and DHA levels were lower, and oleic acid level was higher in fish fed diets containing tallow compared to PC group. Significantly increased aspartate aminotransferase and triglyceride levels were observed in TW group. Dietary supplemented emulsifier restored the reduced performance of olive flounder fed diets containing tallow instead of fish oil. However, the optimum inclusion level of the emulsifier should be elucidated in future studies.

中文翻译：

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日粮中用牛油和乳化剂全替代鱼油对橄榄鲽（Paralichthys olivaceus）生长、饲料利用率和免疫力的影响

研究了乳化剂混合物（聚氧乙烯 (20) 脱水山梨糖醇单月桂酸酯和蒸馏单甘油酯）对橄榄比目鱼Paralichthys olivaceus的饲料利用率、生长性能和免疫力的补充作用，用牛油代替鱼油。含有鱼油的饮食被认为是阳性对照（PC），含有牛油而不是鱼油的饮食被认为是阴性对照（TW）。通过在 TW 日粮中添加 0.01% 和 0.02% 的乳化剂来制备另外两种日粮（EM01 和 EM02）。经过 8 周的饲喂试验后，饲喂 EM01、EM02 或 PC 日粮的鱼的生长性能和饲料利用率显着高于饲喂 TW 日粮的鱼。EM01 和 EM02 日粮的干物质消化率高于 TW 日粮，与 PC 日粮相当。与 TW 饮食相比，PC 饮食的脂质消化率显着更高。与 PC 组相比，含有牛脂的鱼饲料中的肝脏 EPA 和 DHA 水平较低，油酸水平较高。TW组观察到天冬氨酸氨基转移酶和甘油三酯水平显着升高。日粮补充乳化剂恢复了橄榄比目鱼饲喂含有牛油而不是鱼油的日粮的性能下降。然而，乳化剂的最佳包含水平应在未来的研究中阐明。