College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China.
Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
Fish Physiol Biochem. 2024 Dec;50(6):2275-2286. doi: 10.1007/s10695-024-01392-9. Epub 2024 Aug 1.
To investigate the influences of dietary protein and lipid levels on the growth, feed utilization, morphometric parameters, body composition, serum biochemical parameters, and lipid metabolism of golden pompano (Trachinotus ovatus), nine test diets containing three protein levels (35%, 40%, and 45%) and three lipid levels (8%, 13%, and 18%) were designed in the present study. Each diet (named D1-D9) was randomly assigned to feed triplicate groups of golden pompano juvenile (initial weight ~ 70 g) for 50 days. The results showed that the dietary lipid levels positively correlated with weight gain, specific growth rate, and protein efficiency ratio (PER), suggesting that the high lipid diets (18%) can be efficiently utilized in this fish species. The dietary protein levels have no significant influences on the growth and feed utilization except for the PER. Increasing dietary protein levels resulted in a decrease in hepatosomatic index (HSI), viscerosomatic index (VSI), and intestinal somatic index (ISI), while the dietary lipid level did not have a significant impact on morphological indices except for ISI. The dietary protein and lipid levels had no significant influences on the contents of crude lipid, crude ash, and moisture of whole body, while the crude protein contents was significantly affected by the dietary protein levels. Serum biochemical indexes, including cholesterol (CHO), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL), as well as HDL/LDL ratio were significantly affected by the dietary lipid levels, but not by the dietary protein levels. The expression levels of genes and their associated proteins involved in hepatic lipogenesis (Srebp-1c and Fas) and fatty acids β-oxidation (Pparα and Cpt-1) were up-regulated with increasing dietary lipid levels, while the former was up-regulated, and the latter was down-regulated with increasing dietary protein levels. Considering the present results in terms of growth performance, feed utilization, morphometric parameters, and lipid metabolism, the recommended dietary protein and lipid levels for golden pompano are 40% and 18%, respectively. The findings suggested that this species exhibits a significant protein-sparing effect on lipid utilization.
为了研究饲料蛋白质和脂肪水平对金鲳（Trachinotus ovatus）生长、饲料利用、形态参数、体成分、血清生化参数和脂质代谢的影响，本研究设计了 9 种含有 3 种蛋白质水平（35%、40%和 45%）和 3 种脂肪水平（8%、13%和 18%）的试验饲料。每种饲料（命名为 D1-D9）随机分配给 3 组金鲳幼鱼（初始体重约 70 g）进行 50 天的试验。结果表明，饲料脂肪水平与增重、特定生长率和蛋白质效率比（PER）呈正相关，表明高脂肪水平（18%）可以在这种鱼类中得到有效利用。除 PER 外，饲料蛋白质水平对生长和饲料利用没有显著影响。随着饲料蛋白质水平的增加，肝体比（HSI）、脏体比（VSI）和肠体比（ISI）降低，而饲料脂肪水平除 ISI 外对形态指标没有显著影响。饲料蛋白质和脂肪水平对鱼体粗脂肪、粗灰分和水分含量没有显著影响，而粗蛋白含量受饲料蛋白质水平显著影响。血清生化指标，包括胆固醇（CHO）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL）和低密度脂蛋白胆固醇（LDL）以及 HDL/LDL 比值，受饲料脂肪水平显著影响，但不受饲料蛋白质水平影响。肝脂肪生成（Srebp-1c 和 Fas）和脂肪酸β-氧化（Pparα 和 Cpt-1）相关基因及其蛋白的表达水平随饲料脂肪水平的增加而上调，而前者上调，后者下调随饲料蛋白质水平的增加。考虑到生长性能、饲料利用、形态参数和脂质代谢方面的结果，金鲳的推荐饲料蛋白质和脂肪水平分别为 40%和 18%。这些结果表明，该物种对脂肪利用具有显著的蛋白质节约效应。
