Fisheries and Aquaculture program, Department of Animal Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
Secció de Bioquímica i Biologia Molecular, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Joan XXIII 27-31, 08028, Barcelona, Spain.
Fish Physiol Biochem. 2020 Feb;46(1):371-381. doi: 10.1007/s10695-019-00723-5. Epub 2019 Nov 10.
A 90-day randomized feeding experiment was performed to assess the effects of dietary cobalt (Co) supplementation on the growth performance, muscle composition, status of iron and manganese in the muscle as well as the expression of growth-related genes in the muscle (myoblast determination protein 1 homolog (MyoD) and myogenin) and the stress-related gene heat shock protein 70 KDa (Hsp-70) in the liver of mahseer (Tor putitora). Feeding trial was conducted in triplicate under controlled semi-static conditions, and graded levels of dietary cobalt (0.5-3 mg/kg) were fed to six groups of advanced fry of T. putitora. The results obtained indicated a curvilinear relationship of dietary Co levels with body crude protein content and weight gain (%). A positive correlation was observed with up to 2 mg Co/kg diet. However, a decreasing trend was found with values over 2 mg Co/kg diet. The expression of muscle growth biomarkers MyoD and myogenin showed a similar response, upregulation up to 2 mg Co/kg diet and decreased expression at 3 mg Co/kg diet. Indeed, the highest dietary Co supplementation increased the expression of Hsp-70, a key gene expressed in response to stress. Moreover, the muscle content of iron and manganese showed an inverse relationship with the dietary Co supplementation. Our findings suggest that 2 mg/kg Co dietary supplementation stimulates myogenesis and optimize muscle growth and body composition, while higher levels enhanced the expression of stress response genes and impaired growth of T. putitora.
进行了为期 90 天的随机喂养实验，以评估日粮钴（Co）补充对生长性能、肌肉组成、肌肉中铁和锰的状态以及肌肉中与生长相关的基因（成肌决定蛋白 1 同源物（MyoD）和肌生成素）和肝脏中与应激相关的基因热休克蛋白 70 kDa（Hsp-70）的表达的影响。在受控半静态条件下进行了三次重复喂养试验，并向 6 组经过高级孵化的大鳞鱼（Tor putitora）投喂不同水平（0.5-3 mg/kg）的钴日粮。结果表明，日粮 Co 水平与体粗蛋白含量和增重（%）呈曲线关系。在 2 mg Co/kg 饮食中观察到正相关。然而，在超过 2 mg Co/kg 饮食时，发现呈下降趋势。肌肉生长生物标志物 MyoD 和肌生成素的表达也表现出相似的反应，在 2 mg Co/kg 饮食时上调，在 3 mg Co/kg 饮食时表达降低。事实上，最高的钴日粮补充增加了 Hsp-70 的表达，这是一种表达应激反应的关键基因。此外，肌肉中铁和锰的含量与日粮 Co 补充呈反比。我们的研究结果表明，2 mg/kg Co 日粮补充可刺激肌发生并优化肌肉生长和身体成分，而更高水平则增强了应激反应基因的表达，并损害了大鳞鱼的生长。
