Nile tilapia (1.20 g) were fed for 56 days in five treatments (FM100 containing only fish meal [FM] as a protein source; soybean meal (SBM) replace 25%, 50%, 75% and 100% of FM protein in the diets of FM75, FM50, FM25 and FM0, respectively) to assess the effects of dietary protein sources on growth, turnover half‐life of nitrogen and carbon stable isotopes (δ¹³C and δ¹⁵N) in muscle, isotope discrimination factors (Δ¹⁵N and Δ¹³C), and the relative contribution of protein sources to muscle growth. Results showed that the final body weight, weight gain and specific growth rate of fish fed diet FM25 were significantly higher than other treatments (p < .05). By day 35, fish under all treatments reached isotopic equilibrium, and the equilibrium values consistently increase as a function of stable isotope values in diets. Growth accounted for most isotopic changes in muscle and resulted in significantly shorter half‐lives of nitrogen and carbon in FM25 (p < .05). The Δ¹⁵N of FM25 and Δ¹³C of FM0 were significantly lower than other treatments (p < .05). The proportional contributions of SBM protein were significantly higher than their respective levels in FM75 and FM25 (p < .05), indicating a preferential incorporation of nitrogen from the SBM in muscle tissue.

中文翻译：

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使用稳定同位素分析评估日粮罗非鱼（Oreochromis niloticus）中饮食蛋白质来源，生长，养分转化和掺入之间的关系

尼罗罗非鱼（1.20 g）通过五种处理方式（FM100仅包含鱼粉[FM]作为蛋白质来源；豆粕（SBM）代替了25％，50％，75％和100％的FM蛋白）喂养了56天。 FM75，FM50，FM25和FM0，分别地）的饮食，以评估对增长，周转氮和碳的稳定同位素的半衰期（δ膳食蛋白源的影响¹³ C和δ ¹⁵在肌肉N），同位素分辨率因子（δ ¹⁵ N和Δ ¹³ C），和蛋白源肌肉生长的相对贡献。结果表明，饲喂日粮FM25的鱼的最终体重，体重增加和比增长率显着高于其他治疗方法（p <.05）。到第35天，所有处理方法下的鱼都达到了同位素平衡，并且该平衡值随着日粮中稳定同位素值的增加而持续增加。生长是肌肉中大多数同位素变化的原因，并且导致FM25中氮和碳的半衰期大大缩短（p  <.05）。的Δ ¹⁵ FM25的N和Δ ¹³ FM0的温度比其他处理（均显著降低p  <.05）。SBM蛋白的比例贡献显着高于其各自在FM75和FM25中的水平（p  <.05），表明来自SBM的氮优先掺入肌肉组织中。