Liu Wei, Lu Xing, Jiang Ming, Wu Fan, Tian Juan, Yang Changgeng, Yu Lijuan, Wen Hua
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 8, 1st Wudayuan Road, Donghu Hi-Tech Development Zone, Wuhan, 430223, Hubei, China.
College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
Fish Physiol Biochem. 2019 Feb;45(1):21-32. doi: 10.1007/s10695-018-0531-z. Epub 2018 Jul 9.
A 40-day feeding trial was conducted to investigate whether feeding a low-protein diet (25%) once daily for either 10 (L10H30) or 20 (L20H20) days then re-feeding a high-protein diet (35%) thrice daily elicit compensatory growth (CG) in genetically improved farmed tilapia (GIFT), Oreochromis niloticus (11.02 ± 0.05 g). Fish on the control treatment were fed 35% protein diet over 40 days (H40). Fish were stocked into nine 100-L tanks (30 fish per tank) with 3 replicate tanks for each group. Growth performance, feed utilization, proximate composition of body compartment, serum biochemical parameters, and hepatopancreatic histology and expressions of some genes related to inflammatory cytokine were evaluated every 10 days. Growth of L10H30 fish were similar to the control, whereas the weight of L20H20 fish were lower (P < 0.05) at day 20, but this significant difference disappeared at the end of the experiment. During 20-30 days, specific growth rate and feed intake were significantly higher (P < 0.05) and feed efficiency was lower (P < 0.05) in L20H20 fish than those in H40 fish. Dietary manipulations did not affect (P > 0.05) viscerosomatic and hepatosomatic indices, condition factors, serum biochemical parameters, and hepatopancreatic histology. Significant differences (P < 0.05) in proximate composition were observed only in viscera and muscle between L20H20 fish and H40 fish at day 20. The mRNA expressions of heat shock protein 70 kDa, tumor necrosis factor-α and interleukin (IL)-1β were higher (P < 0.05) in L10H30 and L20H20 fish at day 10, while IL-1β mRNA expression was lower (P < 0.05) in L20H20 fish at day 30 than those in H40 fish. Our results indicated that L20H20 fish elicited a complete CG and induced reversible physiological variations in juvenile GIFT.
进行了一项为期40天的饲养试验，以研究对初始体重为（11.02±0.05克）的遗传改良尼罗罗非鱼（GIFT）奥利亚罗非鱼每天投喂一次低蛋白饲料（25%），持续10天（L10H30）或20天（L20H20），然后每天投喂三次高蛋白饲料（35%）是否会引发补偿生长（CG）。对照组的鱼在40天内投喂35%蛋白的饲料（H40）。将鱼放入九个100升的水箱中（每个水箱30条鱼），每组设置3个重复水箱。每10天评估生长性能、饲料利用率、鱼体各部分的近似成分、血清生化参数、肝胰腺组织学以及一些与炎性细胞因子相关基因的表达。L10H30组鱼的生长情况与对照组相似，而L20H20组鱼在第20天时体重较低（P<0.05），但在实验结束时这种显著差异消失。在第20至30天期间，L20H20组鱼的特定生长率和采食量显著高于（P<0.05）H40组鱼，而饲料效率低于（P<0.05）H40组鱼。日粮处理对脏体比、肝体比、肥满度、血清生化参数和肝胰腺组织学没有影响（P>0.05）。仅在第20天时，L20H20组鱼与H40组鱼的内脏和肌肉的近似成分存在显著差异（P<0.05）。在第10天时，L10H30组和L20H20组鱼中70 kDa热休克蛋白、肿瘤坏死因子-α和白细胞介素（IL）-1β的mRNA表达较高（P<0.05），而在第30天时，L20H20组鱼中IL-1β的mRNA表达低于（P<0.05）H40组鱼。我们的结果表明，L20H20组鱼实现了完全补偿生长，并在幼年GIFT中诱导了可逆的生理变化。
