Dietary protein requirements of large‐size Songpu mirror carp (Cyprinus carpio Songpu) were investigated through an an 82‐day feeding trial. Six practical diets were formulated to contain increasing crude protein levels of 240, 260, 280, 300, 320 and 340 g/kg. Six triplicate groups of fish (25 individuals per replicate with initial mean weights of 246.00 ± 17.36 g) were reared in the floating net cages. Results indicated that the highest weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER) and lowest feed conversion ratio (FCR) were observed in the 260 g/kg treatment. The whole‐body crude protein content was significantly higher in the 260 and 280 g/kg treatments (p < .05). The expression of growth hormone (GH) in dorsal white muscle, Rh a glycoprotein (Rhag), Rh b glycoprotein (Rhbg) and Rh c glycoprotein 1 (Rhcg1) in gills increased significantly with increasing protein levels, while the expression of target of rapamycin (TOR), eukaryotic translation initiation factor 4E binding protein 1 (4EBP1) and S6 kinase (S6K) in muscle and intestine increased first and then decreased significantly. Based on these findings, 260 g/kg seems to be the proper level of protein in a practical diet for large‐size Songpu mirror carp (Cyprinus carpio Songpu).

中文翻译：

---

大型松浦镜鲤（Cyprinus carpio Songpu）的膳食蛋白质需求

通过一项为期82天的饲喂试验，研究了大型松浦镜鲤（鲤鱼松浦）的膳食蛋白质需求量。配制了六种实用日粮，使其粗蛋白水平增加了240、260、280、300、320和340 g / kg。在浮动网箱中饲养六组三重复的鱼（每只重复25只，初始平均重量为246.00±17.36 g）。结果表明，在260 g / kg处理中，观察到最高增重率（WGR），比生长率（SGR），蛋白质效率比（PER）和最低饲料转化率（FCR）。在260 g / kg和280 g / kg的处理中，全身粗蛋白含量明显更高（p <.05）。随着蛋白质水平的升高，g中背白肌中生长激素（GH），Rh a糖蛋白（Rhag），Rh b糖蛋白（Rhbg）和Rh c糖蛋白1（Rhcg1）的表达显着增加，而雷帕霉素靶蛋白的表达（TOR），肌肉和肠道中的真核翻译起始因子4E结合蛋白1（4EBP1）和S6激酶（S6K）先升高后显着降低。基于这些发现，对于大型松浦镜鲤（Cyprinus carpio Songpu），在实际饮食中260 g / kg似乎是适当的蛋白质水平。