Abstract：
The wild Onychostoma macrolepis, a species under national class II protection in China, lacks a specific compound feed for captive rearing. Understanding the dietary amino acid pattern is crucial for optimal feed formulation. This study aimed to investigate the effects of the four different dietary amino acid patterns, i.e., anchovy fishmeal protein (FMP, control group) and muscle protein (MP), whole-body protein (WBP), fish egg protein (FEP) of juvenile Onychostoma macrolepis, on the growth performance, body composition, intestinal morphology, enzyme activities, and the expression levels of gh, igf, mtor genes in juveniles. In a 12-week feeding trial with 240 juveniles (3.46±0.04g), the MP group demonstrated superior outcomes in growth performance (FBW, WGR, SGR), feed utilization efficiency (PER, PRE, FCR). Notably, it exhibited higher crude protein content in whole-body fish, enhanced amino acid composition in the liver, and favorable fatty acid health indices (AI, TI, h/H) in muscle compared to other groups (P < 0.05). Morphologically, the MP and FMP groups exhibited healthy features. Additionally, the MP group displayed significantly higher activities of TPS, ALP, and SOD, along with elevated expression levels of gh, igf, mtor genes, distinguishing it from the other groups (P < 0.05). This study illustrated that the amino acid pattern of MP emerged as a suitable dietary amino acid pattern for juvenile Onychostoma macrolepis. Furthermore, the findings provide valuable insights for formulating effective feeds in conserving and sustainably farming protected species, enhancing the research\'s broader ecological and aquacultural significance.
摘要：
野生玛瑙，中国受国家二类保护的物种,缺乏用于圈养的特定复合饲料。了解膳食氨基酸模式对于最佳饲料配方至关重要。本研究旨在探讨4种不同氨基酸模式对饲粮的影响,即，凤尾鱼鱼粉蛋白(FMP，对照组）和肌肉蛋白（MP），全身蛋白（WBP），鱼卵蛋白（FEP），关于增长表现，身体成分,肠道形态学,酶活性，gh的表达水平，igf,青少年的mtor基因。在一项为期12周的240只幼鱼喂养试验中（3.46±0.04g），MP组在增长绩效方面表现出优异的结果(FBW，WGR,SGR)，饲料利用效率(PER，PRE,FCR）。值得注意的是,它在全身鱼类中表现出更高的粗蛋白含量，增强肝脏中的氨基酸组成，和有利的脂肪酸健康指数(AI，TI,h/h）在肌肉中与其他组相比（P<0.05）。形态学上,MP和FMP组表现出健康特征。此外,MP组显示出较高的TPS活性，ALP,和SOD，随着gh表达水平的升高，igf,mtor基因，将其与其他组区分开(P<0.05)。这项研究表明，MP的氨基酸模式已成为青少年大甲鱼的合适饮食氨基酸模式。此外，这些发现为在保护和可持续养殖受保护物种中制定有效的饲料提供了宝贵的见解，加强研究的更广泛的生态和水产养殖意义。
