Two different experiments with rainbow trout fry were carried out to evaluate the effect of different grape pomace (GP) levels in feed on growth performance and apparent digestibility. The first experiment used 0, 20, 40, and 60 g kg⁻¹ GP (D0, D2, D4, and D6, respectively); the second experiment used 0, 60, 120, and 180 g kg⁻¹ GP (D0, D6, D12, and D18, respectively). Total polyphenols in the diet ranged from 0 to 8.19 mg g⁻¹ in D0–D18. At the end of the first and second experiments (83 days and 77 days, respectively), no significant differences in fish growth were observed between the different diets. On the other hand, feed containing up to 2.7 mg g⁻¹ total polyphenols (D6) showed a significantly higher digestibility relative to feed with more than 5.5 mg g⁻¹ total polyphenols (D12). Our findings suggest that the inclusion of GP at levels of up to 18% in feed for Oncorhynchus mykiss fry did not affect growth parameters. However, it did influence apparent digestibility; fry that consumed diet D6 showed benefits in terms of nutrient digestibility and feed conversion efficiency.

中文翻译：

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在虹鳟鱼苗（Oncorhynchus mykiss）的配方饲料中使用葡萄渣（Walbaum，1792年）

进行了两个不同的虹鳟鱼苗实验，以评估饲料中不同葡萄果渣（GP）水平对生长性能和表观消化率的影响。第一个实验使用了0、20、40和60 g kg ^-1 GP（分别为D0，D2，D4和D6）；第二个实验使用了0、60、120和180 g kg ^-1 GP（分别为D0，D6，D12和D18）。日粮中D0–D18中的总多酚含量为0至8.19 mg g ^-1。在第一个和第二个实验结束时（分别为83天和77天），不同日粮之间的鱼生长没有显着差异。另一方面，饲料中最多含2.7 mg g ^-1总饲料中的多酚（D6）相对于饲料中总酚含量超过5.5 mg g ^-1（D12）的饲料具有明显更高的消化率。我们的研究结果表明，Oncorhynchus mykiss鱼苗的饲料中GP含量高达18％不会影响生长参数。但是，它确实影响了表观消化率。食用日粮D6的鱼苗在养分消化率和饲料转化效率方面显示出优势。