Replacement of fishmeal as the major protein source in feeds is critical for continued growth and sustainability of the aquaculture industry. However, numerous studies have shown suboptimal fish growth performance and reduced protein retention efficiency when carnivorous fish species are fed low fishmeal-high plant protein feeds. A study was conducted using a commercial strain and a genetically improved strain of rainbow trout selected for improved performance when fed an all plant protein diet to identify physiological differences associated with growth performance in the selected trout strain. Fifty individuals per strain (average weight ~ 580 g) were force-fed a plant-protein blend with and without amino acid supplementation (lysine, methionine and threonine) at 0.5% body weight and sampled at intervals over 24 h. Samples from intestine and liver were analyzed for specific gene expression analysis related to amino acid transporters, digestive process control, protein degradation and amino acid metabolism. The results showed that expression levels of various intestinal amino acid transporters (SLC1A1, SLC7A9, SLC15A, SLC1A5 SLC6A19 and SLC36A1) were affected by strain, diet and time. Moreover, significant interactions were found regarding the temporal expression levels of cholecystokinin (CCK-L), Krüppel-like factor 15 (KLF15) and aspartate aminotransferase (GOT) transcripts in the examined tissues. The results provide evidence that improved growth and protein retention of the selected strain fed an all-plant protein diet is a result of nutritional adaptation and an overall change in physiological homeostatic control.

取代鱼粉作为饲料中的主要蛋白质来源对于水产养殖业的持续增长和可持续性至关重要。然而，许多研究表明，当肉食性鱼类喂食低鱼粉高植物蛋白饲料时，鱼的生长性能不佳，蛋白质保留效率降低。一项研究是使用商业品系和经过基因改良的虹鳟鱼品系进行的，该品系在饲喂全植物蛋白日粮时为提高性能而选择，以确定与所选鳟鱼品系的生长性能相关的生理差异。每个菌株 50 个人（平均体重约 580 克）被强制喂食添加和不添加氨基酸（赖氨酸、蛋氨酸和苏氨酸）的 0.5% 体重的植物蛋白混合物，并在 24 小时内每隔一段时间取样。对来自肠道和肝脏的样本进行了与氨基酸转运蛋白、消化过程控制、蛋白质降解和氨基酸代谢相关的特定基因表达分析。结果表明，各种肠道氨基酸转运蛋白（SLC1A1、SLC7A9、SLC15A、SLC1A5、SLC6A19和SLC36A1）的表达水平受菌株、饮食和时间的影响。此外，在所检查的组织中，胆囊收缩素 (CCK-L)、Krüppel 样因子 15 (KLF15) 和天冬氨酸转氨酶 (GOT) 转录物的时间表达水平发现了显着的相互作用。结果提供的证据表明，以全植物蛋白质饮食喂养的选定菌株的生长和蛋白质保留改善是营养适应和生理稳态控制的整体变化的结果。