To investigate the mechanism underlying the difference of dietary protein requirements among Erythroculter ilishaeformis line, Ancherythroculter nigrocauda line and their hybrid F₁ (E. ilishaeformis♀×A. nigrocauda ♂), juvenile fish of these three species with initial body weight (5.86 ± 0.10 g) were fed the six isoenergy diets with different dietary protein/carbohydrate ratios (P/C ratios were 0.56, 0.78, 1.11, 1.61, 2.52 and 4.43, respectively) for 8 weeks. The results showed that the hybrid culter had the higher weight gain rate (WGR), protein efficiency ratio and protein deposition ratio compared with its parents lines; using WGR as a response criteria, the dietary carbohydrate tolerant level of juvenile E. ilishaeformis line, A. nigrocauda line and their hybrid was 24.3%, 28.5% and 29.7%, respectively, and the optimal P/C ratio was 1.69, 1.35, 1.22 and respectively. Dietary carbohydrate activated hepatic protein kinase B (Akt), dietary protein activated hepatic target of rapamycin (TOR) and the induction of mRNA expression of hepatic phosphoenolpyruvate carboxykinase and pyruvate kinase showed a similar change in hybrid F₁ and its parents. A. nigrocauda had the highest enzymes activities in intestinal protease and amylase, and hybrid culter had the highest intestinal lipase activities. Our results demonstrated that the hybrid culter has the better protein‐sparing effects by increasing carbohydrate metabolism than its parent lines.

中文翻译：

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蛋白质/碳水化合物比例不同的幼年赤红系，黑黑无翅系及其杂种F1代饲粮中减蛋白作用的比较研究

调查机构的饮食蛋白质要求的差底层之间翘嘴红鲌线，Ancherythroculter尾近红鲌线和它们的杂种F1 ₁（E. ilishaeformis ♀× A.尾近红鲌♂），这三个物种与初始体重（5.86±0.10的幼鱼g）分别喂食六种具有不同饮食蛋白质/碳水化合物比例（P / C比例分别为0.56、0.78、1.11、1.61、2.52和4.43）的等能量饮食，持续8周。结果表明，与亲本相比，该杂交种具有较高的增重率，蛋白质效率比和蛋白质沉积比。使用WGR作为响应标准，青少年的饮食碳水化合物耐受水平大肠杆菌，黑线草及其杂交种分别为24.3％，28.5％和29.7％，最佳P / C比分别为1.69、1.35、1.22和。膳食碳水化合物激活的肝蛋白激酶B（Akt），膳食蛋白激活的雷帕霉素肝靶标（TOR）以及肝磷酸烯醇丙酮酸羧激酶和丙酮酸激酶的mRNA表达诱导在杂种F ₁及其亲本中表现出相似的变化。黑曲霉在肠蛋白酶和淀粉酶中具有最高的酶活性，而杂种栽培者具有最高的肠脂酶活性。我们的结果表明，杂种除草剂通过增加碳水化合物的代谢而比其亲本具有更好的蛋白质保留作用。