Younis El-Sayed M, Al-Quffail Abdullah S, Al-Asgah Nasser A, Abdel-Warith Abdel-Wahab A, Al-Hafedh Yousef S
Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.
King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
Saudi J Biol Sci. 2018 Feb;25(2):198-203. doi: 10.1016/j.sjbs.2017.06.012. Epub 2017 Jun 20.
A 12-week long feeding experiment was initiated to evaluate the effect of dietary supplementation of red algae, , on the growth performance, feed utilization and body composition of Nile tilapia (Linnaeus, 1758). The fish were fed with an algae-free control diet (C) and three experimental diets which replaced conventional fish meal with varying levels of dried (20%, 40% and 60%, represented as G20, G40 and G60, respectively). The growth parameters of final weight (FW), weight gain (WG), percentage of weight gain (WG%), daily growth rate (DGR) and specific growth rate (SGR) were significantly reduced (P < 0.05) at all levels of algae incorporation compared to the control diet. Moreover, the negative impact of meal on the growth performance of Nile tilapia increased as the proportion of algae in the diet increased, with fish on diet G20 exhibiting a significantly higher growth performance than the fish on either of the G40 and G60 diets. On the other hand, the feed utilization parameters feed conversion ratio (FCR) and protein efficiency ratio (PER) did not show significant differences between the fish in the control group and those on diet G20, although poorer FCR and PER outcomes were achieved in the case of fish on diet G60. The content of moisture, protein and ash in muscle and carcass increased as the proportion of meal in the diets increased, but the reverse was true for lipid level. These results indicate that incorporation of less than 20% red algae, , could be feasible in the diet of Nile tilapia and further studies are recommended to optimize the level of algae to improve growth performance.
开展了一项为期12周的投喂实验，以评估日粮中添加红藻对尼罗罗非鱼（Linnaeus，1758）生长性能、饲料利用率和体成分的影响。给鱼投喂不含藻类的对照日粮（C）和三种实验日粮，这三种日粮用不同水平的干（分别为20%、40%和60%，分别表示为G20、G40和G60）替代了传统鱼粉。与对照日粮相比，在所有藻类添加水平下，最终体重（FW）、增重（WG）、增重百分比（WG%）、日生长率（DGR）和特定生长率（SGR）等生长参数均显著降低（P < 0.05）。此外，随着日粮中藻类比例的增加，对尼罗罗非鱼生长性能的负面影响增大，日粮为G20的鱼的生长性能显著高于日粮为G40和G60的鱼。另一方面，对照组鱼和日粮为G20的鱼之间的饲料利用率参数饲料转化率（FCR）和蛋白质效率比（PER）没有显著差异，尽管日粮为G60的鱼的FCR和PER结果较差。肌肉和鱼体中水分、蛋白质和灰分的含量随着日粮中比例的增加而增加，但脂质水平则相反。这些结果表明，在尼罗罗非鱼日粮中添加低于20%的红藻可能是可行的，建议进一步研究以优化藻类水平，提高生长性能。
