State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China.
University of Chinese Academy of Sciences, Beijing, PR China.
PLoS One. 2022 Feb 4;17(2):e0263507. doi: 10.1371/journal.pone.0263507. eCollection 2022.
A 65-day growth trial was conducted to investigate the dietary protein requirements for Culter mongolicus fingerlings. Isolipidic and isoenergetic diets were formulated with five dietary protein levels (32%, 37%, 42%, 47%, and 52%). Each diet was assigned to triplicate groups of 70 C. mongolicus fingerlings (0.99±0.08 g). The results indicated that weight gain and specific growth rate (SGR) increased with increasing dietary protein levels up to 47%. The activities of intestinal trypsin and lipase were the lowest in the 32% protein and 52% protein groups, while amylase activity reduced markedly in the 47% protein group. These results suggest that different dietary protein levels may cause different transformations of nutrients. The activities of superoxide dismutase (SOD) and lysozyme were not affected by varying dietary protein levels, except for those in the 32% protein group. In contrast, the content of malondialdehyde (MDA) increased with increasing dietary protein levels and reaching a maximum in the 52% protein group, suggesting that MDA accumulation depends on the protein concentration and the potential oxidative stress. Taken together, based on the broken-line analysis of SGR, we recommended the optimum dietary protein for C. mongolicus fingerlings to be 48.97%~49.31%.
进行了为期 65 天的生长试验，以研究蒙古鲌幼鱼的蛋白质需要量。用 5 种蛋白质水平（32%、37%、42%、47%和 52%）配制等脂和等能饲料。将每种饲料分配给 3 组 70 尾蒙古鲌幼鱼（0.99±0.08 g）。结果表明，体重增加率和特定生长率（SGR）随蛋白质水平的增加而增加，最高可达 47%。肠道胰蛋白酶和脂肪酶的活性在 32%和 52%蛋白组中最低，而 47%蛋白组的淀粉酶活性显著降低。这些结果表明，不同的蛋白质水平可能导致不同的营养素转化。超氧化物歧化酶（SOD）和溶菌酶的活性不受蛋白质水平变化的影响，除了 32%蛋白组之外。相反，丙二醛（MDA）的含量随蛋白质水平的增加而增加，在 52%蛋白组中达到最大值，表明 MDA 的积累取决于蛋白质浓度和潜在的氧化应激。总之，根据 SGR 的折线分析，我们建议蒙古鲌幼鱼的最佳蛋白质摄入量为 48.97%~49.31%。
