Li Peiyu, Song Zhidong, Huang Long, Sun Yongzhi, Sun Yuming, Wang Xiaoyan, Li Lu
Yantai Key Laboratory of Quality and Safety Control and Deep Processing of Marine Food, Shandong Marine Resource and Environment Research Institute, Yantai 264006, China.
Yantai Zhulin Human Resources Service Co. Ltd, Yantai 264006, China.
Aquac Nutr. 2023 Aug 8;2023:9970252. doi: 10.1155/2023/9970252. eCollection 2023.
A 3 × 2 factorial experiment (protein levels, 42%, 46%, 50%; lipid levels, 9%, 12%) with three replicates was conducted in a circulating water system to investigate the effects of dietary protein and lipid levels on growth, feed utilization, body composition, and serum biochemical parameters of growing rockfish (initial weight, 29.98 ± 0.10 g). After an 8 weeks feeding trial, growth performance in terms of final body weight, percent weight gain, and specific growth rate increased with the increase of dietary protein level when fish fed diets containing a consistent level of dietary lipid. The feed conversion rate and daily feed intake were significantly affected by dietary protein and lipid levels, and decreased as dietary protein level increased from 42% to 46% or dietary lipid level increased from 9% to 12% ( < 0.05). Survival rate, viscerosomatic index, and hepatosomatic index were unaffected by dietary protein level ( > 0.05), but significantly increased with the increase of dietary lipid level ( < 0.05). On the contrary, condition factor was unaffected by dietary lipid level ( > 0.05), but significantly increased with dietary protein level increasing up to 46% ( < 0.05). The moisture contents of muscle and liver significantly decreased, but the whole-body crude lipid content, the crude protein and lipid contents of muscle increased as dietary protein or lipid level increased ( < 0.05). The contents of isoleucine, leucine, histidine, glycine, alanine of muscle, as well as the proportions of C14 : 0, C20 : 1, and C22 : 1n-9 in total fatty acids were higher in fish fed diets containing 12% lipid than those fed 9% lipid ( < 0.05), while C18 : 1n-9 and C18 : 2n-6 followed an opposite trend. The contents of phenylalanine, lysine, and tyrosine as well as the proportions of C18 : 0, C18 : 2n-6, C22 : 1n-9, and C22 : 6n-3 in total fatty acids decreased with the increase of dietary protein level ( < 0.05). Serum cholesterol and low-density lipoproteins increased significantly with dietary protein or lipid levels increasing, but TG concentration was elevated significantly in fish fed diets containing 12% lipid. Considering the present results in terms of growth and feed utilization, the suitable protein and lipid levels in diet for growing rockfish were 46% and 12%, respectively.
在循环水系统中进行了一项3×2析因试验（蛋白质水平为42%、46%、50%；脂肪水平为9%、12%），重复三次，以研究日粮蛋白质和脂肪水平对生长中的岩鱼（初始体重29.98±0.10克）生长、饲料利用、体成分和血清生化参数的影响。经过8周的饲养试验，当鱼饲喂含有一致脂肪水平的日粮时，终末体重、增重百分比和特定生长率方面的生长性能随着日粮蛋白质水平的增加而提高。饲料转化率和日采食量受日粮蛋白质和脂肪水平显著影响，当日粮蛋白质水平从42%增加到46%或日粮脂肪水平从9%增加到12%时下降（P<0.05）。存活率、脏体比和肝体比不受日粮蛋白质水平影响（P>0.05），但随着日粮脂肪水平的增加而显著增加（P<0.05）。相反，肥满度不受日粮脂肪水平影响（P>0.05），但随着日粮蛋白质水平增加到46%而显著增加（P<0.05）。肌肉和肝脏的水分含量显著下降，但随着日粮蛋白质或脂肪水平的增加，鱼体粗脂肪含量、肌肉粗蛋白和粗脂肪含量增加（P<0.05）。饲喂含12%脂肪日粮的鱼肌肉中的异亮氨酸、亮氨酸、组氨酸、甘氨酸、丙氨酸含量以及总脂肪酸中C14:0、C20:1和C22:1n-9的比例高于饲喂含9%脂肪日粮的鱼（P<0.05），而C18:1n-9和C18:2n-6则呈相反趋势。苯丙氨酸、赖氨酸和酪氨酸含量以及总脂肪酸中C18:0、C18:2n-6、C22:1n-9和C22:6n-3的比例随着日粮蛋白质水平的增加而降低（P<0.05）。血清胆固醇和低密度脂蛋白随着日粮蛋白质或脂肪水平的增加而显著增加，但饲喂含12%脂肪日粮的鱼甘油三酯浓度显著升高。就生长和饲料利用方面的当前结果而言，生长中岩鱼日粮中合适的蛋白质和脂肪水平分别为46%和12%。
