Department of Ecology and Conservation Biology, Texas A&M University System, College Station, TX, 77843-2258, USA.
Fish Physiol Biochem. 2023 Jun;49(3):399-407. doi: 10.1007/s10695-023-01196-3. Epub 2023 Apr 18.
The effects of dietary supplementation of creatine and guanidinoacetic acid (GDA) have been studied to a limited extent in various fish species including red drum (Sciaenops ocellatus) and hybrid striped bass (HBS) (Morone saxatilis x M. chrysops). However, in HSB, there is a need to better understand the impact of creatine and GDA supplementation at elevated salinity which may be encountered by this euryhaline fish. Therefore, two separate feeding trials were conducted at a salinity ranging from 15 to 20 g/L with juvenile HSB for 9 and 8 weeks to evaluate the effects of dietary creatine and GDA. In each trial, four diets were formulated with either singular additions of creatine at 2% of dry weight, GDA at 1% of dry weight, or a combination of both. Fish grew adequately in both feeding trials but no significant (P > 0.05) effects of supplemental creatine or GDA were observed on weight gain, feed efficiency, survival, hepatosomatic index (HSI), intraperitoneal fat (IPF ratio), or protein conversion efficiency (PCE). However, fish fed diets supplemented with creatine had significantly (P < 0.05) increased ash and reduced lipid deposition in whole-body tissues in the first feeding trial. Supplemental creatine also resulted in significantly higher muscle yield in the second trial, but no other effects on growth performance or body composition were observed. The addition of GDA to the diet had little effect except for significantly increasing the creatine content in the liver of fish in both feeding trials due to its role as a precursor and a catalyst for synthesis of creatine within the body. Based on the results of these two trials, supplemental creatine and GDA had rather limited effects on HSB cultured in moderately saline water.
在包括红鼓鱼（Sciaenops ocellatus）和杂交条纹鲈（HBS）（Morone saxatilis x M. chrysops）在内的各种鱼类中，已经有限地研究了膳食补充肌酸和胍基乙酸（GDA）的效果。然而，对于这种广盐性鱼类，需要更好地了解在可能遇到的高盐度下补充肌酸和 GDA 的影响。因此，在盐度范围为 15 至 20 g/L 的条件下，对幼龄 HSB 进行了两次单独的喂养试验，为期 9 和 8 周，以评估饮食中肌酸和 GDA 的影响。在每个试验中，都用 4 种饲料配方进行了实验，这些配方分别单独添加了 2%的肌酸、1%的 GDA，或两者的组合。在两次喂养试验中，鱼都能正常生长，但未观察到补充肌酸或 GDA 对体重增加、饲料效率、存活率、肝体比（HSI）、腹腔内脂肪（IPF 比）或蛋白质转化率（PCE）有显著影响（P > 0.05）。然而，在第一次喂养试验中，饲喂添加肌酸的饲料的鱼的灰分显著增加（P < 0.05），全身组织中的脂质沉积减少。在第二次试验中，补充肌酸还导致肌肉产量显著增加，但对生长性能或身体成分没有其他影响。除了由于其作为体内肌酸合成的前体和催化剂的作用而导致肝脏中的肌酸含量在两次喂养试验中均显著增加之外，GDA 添加到饲料中几乎没有其他影响。基于这两项试验的结果，在中等盐度水中培养的 HSB 中，补充肌酸和 GDA 的效果相当有限。
