相同EAA模式下不同日粮蛋白水平对草鱼肌肉、肝胰脏蛋白周转代谢的影响

在日粮必需氨基酸模式相同条件下 ,研究不同日粮蛋白水平对草鱼肌肉、肝胰脏蛋白质周转代谢的影响。其中周转代谢参数包括 :蛋白质的合成速率 (FSR)、降解速率 (FDR)、生长速率 (FGR)、合成能力 (CS)、合成的翻译效率 (KRNA)和蛋白质沉积效率 (PRE)。试验结果表明 :1.日粮蛋白水平的增加促进了草鱼的生长 ,促进了肌肉、肝胰脏蛋白质的增长。饲料转化效率和肌肉蛋白质沉积效率在适宜蛋白水平时最高。2.肌肉FSR、FDR与日粮蛋白水平呈正相关关系 ;肝胰脏蛋白FSR不受日粮蛋白水平的影响 ,蛋白质FDR与日粮蛋白水平呈负相关关系。3.肌肉蛋白FGR的增加归因于蛋白质合成的增长较降解的增长更占优势 ,以及蛋白质合成的KRNA 的提高 ;肝胰脏蛋白FGR的增加归因于蛋白质降解的减少。4.肌肉、肝胰脏蛋白CS不受日粮蛋白水平的影响。5.肌肉PRE(生长占合成的比例 )在适宜蛋白质水平 (30 % )时最高 ,而且在该水平下饲料系数最低 ,即饲料转化率最高

EFFECTS OF DIETARY PROTEIN LEVELS WITH SAME EAA PETTERN ON PROTEIN TURNOVER IN MUSCLE AND HEPATOPANCREAS OF GRASS CARPS

The effects of dietary different protein levels with same EAA pattern on growth and protein turnover parameters were studied.The results showed that:1.The increase of dietary protein level improved growth of grass carps and their protein retention of muscle and hepatopancreas.2.Muscular protein synthesis and degradation rates were positively related to dietary protein levels;although hepatopancreatic protein synthesis rate was not affected by the protein levels,the rate of degradation was negatively related to protein levels.3.The increase of protein synthesis gave more priority to muscular protein growth rate than increase of protein degradation did,so they did to the increase of transitional efficiency of protein synthesis(the synthesized protein per unit of RNA,meanwhile), increase of hepatopancreatic protein growth rate was attributive to decrease of the protein degradation.4.At 30% dietary protein level,the muscular protein retention efficiency(the proportion of growth to synthesis) had a optimistic utilization and a lowest feed coefficient,which means a highest feed utilization.