The use of stable isotopes to investigate the effects of supplemental lysine and methionine on protein turnover and amino acid utilization in pacu, Piaractus mesopotamicus, juveniles
The use of stable isotopes to investigate the effects of supplemental lysine and methionine on protein turnover and amino acid utilization in pacu, Piaractus mesopotamicus, juveniles
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DOI：
10.1016/j.aquaculture.2014.06.006
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发表时间：
2014-09
期刊：
影响因子：
4.5
通讯作者：
E. G. Abimorad;C. Ducatti;D. Castellani;R. K. Jomori;M. C. Portella;Dalton Jose Cameiro
中科院分区：
文献类型：
--
作者：
E. G. Abimorad;C. Ducatti;D. Castellani;R. K. Jomori;M. C. Portella;Dalton Jose Cameiro
本研究探讨了使用稳定同位素技术，以评估营养缺乏的饮食，提供或不提供赖氨酸和/或蛋氨酸，对生物元素（碳和氮）的同位素周转的pacu少年肌肉组织的影响。此外，它评估了生长速率（k）和代谢速率（m）的同位素周转的贡献。以初始体重为10 g的鱼为试验对象，分别饲喂不添加氨基酸（AAd）或添加赖氨酸（Lys）、蛋氨酸（Met）和赖氨酸-蛋氨酸（LysMet）的4种试验饲料100 d。在此期间，从鱼的肌肉样品进行同位素特征分析，并计算δ 13 C和δ 15 N周转率。赖氨酸和赖氨酸蛋氨酸组的增重、生长率、摄食量和饲料转化率均显著高于AAd组（P <0.05）。补充Met的鱼显示中等生长性能。应用指数模型表明，赖氨酸和赖氨酸蛋氨酸饲料中的鱼有最低的周转率和判别因子（），特别是δ 15 N。在AAd和Met饲料中观察到δ 15 N的半衰期较低。稳定同位素技术显示，饲粮中赖氨酸的供应降低了以植物蛋白为基础的饲料喂养的太平洋小鸦幼鱼的肌肉蛋白质催化量（m），并促进了生长（k）。因此，我们证明了稳定同位素技术，特别是15N，是营养研究中的一个有用工具，提供了同位素周转率的信息。
The present study investigated the use of the stable isotope technique to evaluate the effects of nutritionally deficient diets, supplied or not with lysine and/or methionine, on the isotopic turnover of bio-elements (carbon and nitrogen) in the muscle tissue of pacu juveniles. In addition, it evaluated the contributions of growth rate (k) and metabolic rate (m) to isotopic turnover. Fish with initial weight of 10 g were fed 4 experimental diets for 100 days: a nutritionally deficient diet without amino acid supplementation (AAd) or supplemented with lysine (Lys), methionine (Met) and lysine–methionine (LysMet). During this period, muscle samples were taken from the fish to analyze isotopic signature and calculate δ13C and δ15N turnover rates. Fish fed Lys and LysMet diets exhibited higher weight gain, growth rate, feed consumption and apparent feed conversion (P< 0.05) than fish fed AAd. Fish supplemented with Met displayed intermediate growth performance. The exponential model applied indicated that fish fed Lys and LysMet diets had the lowest turnover rates and discrimination factors (∆), particularly for δ15N. Lower half-life for δ15N was observed in fish fed AAd and Met diets. As indicated by the stable isotope technique, dietary lysine supply reduces muscle protein catabolism (m) and improves growth (k) in pacu juveniles fed plant protein-based diets. Therefore, we proved that the stable isotope technique, particularly15N, is a useful tool in nutritional studies, providing information on isotopic turnover rates.