The present study was carried out to evaluate the potential of two common freshwater macrophytes (Ceratophyllum demersum and Potamogeton amplifolius) as feed ingredients for Nile tilapia fingerlings, in two consecutive experiments. The first experiment investigated the use of raw, dried C. demersum and P. amplifolius as sources of energy in the diets of fingerlings. The macrophytes were incorporated in 6 isonitrogenous and isocaloric diets at four levels as a replacement of dietary wheat bran. The test diets were fed to triplicate groups, stocked in 140 L culture aquaria in a recirculating system, three times a day to satiation, for 45 days. The results showed that control, macrophyte-free diet produced significantly improved growth rates and feed utilization efficiency than macrophytes-based diets.
In Experiment 2, fermented C. demersum and P. amplifolius were incorporated into six isonitrogenous and isocaloric diets. The diets were fed to triplicate groups of fingerlings (35 g) for 45 days. Growth rates and feed utilization efficiency of fish fed with fermented P. amplifolius at 33 % and 66 % inclusion level were not significantly different from fish fed the control diet. At 100 % inclusion level, fish performance was significantly reduced. On the other hand, fermented C. demersum produced extremely poor performance, compared to raw ceratophyllum. In conclusion, the present results indicated that fermentation improved the quality of P. amplifolius; but not C. demersum.

中文翻译：

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评价两种淡水大型植物，Ceratophyllum demersum和Potamogeton amplifoliusas饲料成分，用于尼罗罗非鱼（Oreochromis niloticus）鱼种

在两个连续的实验中，本研究旨在评估两种常见的淡水大型植物（Ceratophyllum demersum和Potamogeton amplifolius）作为尼罗罗非鱼鱼种饲料原料的潜力。第一个实验研究了使用原始的，干燥的C. demersum和P. amplifolius作为鱼种饮食中的能量来源。将大植物以四种水平掺入6种等氮和等热量日粮中，以替代膳食麦麸。将测试饮食分为三组，分别放入循环系统中的140 L培养水族箱中，每天3次，直至饱食，持续45天。结果表明，与不含大型植物的饮食相比，无大型植物的控制饮食可显着提高生长速度和饲料利用率。
在实验2中，将发酵的C. demersum和P. amplifolius掺入六种等氮和等热量饮食中。日粮喂食三组鱼种（35克）45天。发酵鱼饲料的生长率和饲料利用率包涵体含量为33％和66％的扩增假单胞菌与饲喂对照饮食的鱼无显着差异。在100％的夹杂水平下，鱼类的生长性能显着下降。另一方面，与原始角藻相比，发酵后的梭状芽孢杆菌产生的性能极差。总之，目前的结果表明，发酵提高了P. amplifolius的质量。但不是德美梭菌。