Effects of dietary lipid levels on sub-adult triploid rainbow trout (Oncorhynchus mykiss): 1. Growth performance, digestive ability, health status and expression of growth-related genes
Effects of dietary lipid levels on sub-adult triploid rainbow trout (Oncorhynchus mykiss): 1. Growth performance, digestive ability, health status and expression of growth-related genes
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膳食脂质水平对亚成体三倍体虹鳟鱼（Oncorhynchus mykiss）的影响：1.生长性能、消化能力、健康状况和生长相关基因表达
DOI：
10.1016/j.aquaculture.2019.734394
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发表时间：
2019-11-15
期刊：
影响因子：
4.5
通讯作者：
Li, Changzhong
中科院分区：
文献类型：
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作者：
Meng, Yuqion;Qian, Kangkang;Li, Changzhong
生长试验旨在评估日粮脂质水平对雌性三倍体虹鳟鱼（Oncorhynchus mykiss）生长性能、饲料利用率、消化能力、健康状况和生长相关基因表达的影响。配制了六种含 46% 蛋白质的等氮日粮，其脂质水平分级为 6.6（日粮 1）、12.3（日粮 2）、14.8（日粮 3）、19.5（日粮 4）、22.8（日粮 5）和 29.4%（日粮 6）。将每种饲料喂给淡水网箱中初始平均重量为 233 克的四组鱼，持续 80 天。结果表明，亚成鱼的生长性能、饲料利用率、消化能力和健康状况均存在显着的线性和二次响应（P < .05）。最终体重、特定生长率（SGR）、采食量（FI）、胃蛋白酶活性、幽门盲肠脂肪酶活性、幽门盲肠和肠道淀粉酶活性均随饲料蛋白质水平的增加而呈增加趋势。饲料转化率（FCR）随着日粮蛋白质水平的增加而降低。除了在饮食 6 处理中发现肌层厚度和杯状细胞密度最高值 (P < .05) 外，在任何组中均未观察到肠道形态的显着差异 (P > .05)。在检查健康状况时，肠道和肝脏的抗氧化能力没有发现负面影响（P > .05），但饮食6治疗中血浆总抗氧化能力（T-AOC）含量最低，血浆丙二醛（MDA）含量最高（P < .05）。除天冬氨酸转氨酶 (AST) 和肌酸激酶 (CK) 活性随膳食脂质水平增加而增加 (P < .05) 外，各组血浆酶均无显着差异 (P > .05)。生长相关基因的表达首先显着提高（P < .05），然后保持一致（P > .05）。 FCR折线回归分析表明，本研究中三倍体虹鳟鱼的最低膳食脂质水平为23.3%。总之，我们发现三倍体虹鳟鱼可以使用或耐受高膳食脂质水平（高达29.4％），并且对鱼类生长、饲料利用率、肝脏或肠道健康没有负面影响。根据目前条件下的 FCR，亚成体三倍体虹鳟鱼的最低膳食脂质水平估计为 23.3%。
A growth trial was conducted to evaluate the effects of dietary lipid levels on the growth performance, feed utilization, digestive ability, health status and expression of growth-related genes of female triploid rainbow trout (Oncorhynchus mykiss). Six isonitrogenous diets, containing 46% protein were formulated with graded lipid levels of 6.6 (Diet 1), 12.3 (Diet 2), 14.8 (Diet 3), 19.5 (Diet 4), 22.8 (Diet 5) and 29.4% (Diet 6). Each diet was fed to quadruplicated groups of fish with initial average weight of 233 g in freshwater cages for 80 days. Results showed that there were significant linear and quadratic responses in growth performance, feed utilization, digestive ability and health status of sub-adult fish (P < .05). Final weight, specific growth rate (SGR), feed intake (FI), stomach protease activity, activity of lipase in pyloric caeca, activity of amylase in pyloric caeca and intestine showed a general increasing trend with increasing dietary protein level. Feed conversion ratio (FCR) decreased with increasing dietary protein level. No significant difference of intestinal morphology was observed in any of the groups (P > .05) except that the highest value for muscular layer thickness and density of goblet cells were found in Diet 6 treatment (P < .05). When examining health status, no negative effects were found in the antioxidative capacity of the intestine and liver (P > .05), however, the lowest value of plasma total antioxidative capacity (T-AOC) content and highest plasma malonaldehyde (MDA) content were shown in Diet 6 treatment (P < .05). There was no significant difference in plasma enzymes in any of the groups (P > .05) except for activities of aspartate aminotransferase (AST) and creatine kinase (CK), which increased as dietary lipid levels increased (P < .05). The expression of growth-related genes was at first significantly improved (P < .05) and then kept consistent (P > .05). Broken-line regression analysis of FCR showed that the minimum dietary lipid level of triploid rainbow trout was 23.3% in the present study. In summary, we found that triploid rainbow trout could use or tolerate high dietary lipid level (up to 29.4%) with no negative effect on fish growth, feed utilization, liver or intestine health. The minimum dietary lipid level for sub-adult triploid rainbow trout was estimated to be 23.3% based on FCR under the present conditions.