Chen Xiu-Mei, Guo Gui-Liang, Sun Li, Yang Qiu-Shi, Wang Gui-Qin, Qin Gui-Xin, Zhang Dong-Ming
College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China.
Testing Center of Quality and Safety in Aquatic Product, 777 CaiYu Road, Changchun, Jilin, China.
Fish Shellfish Immunol. 2016 Apr;51:365-372. doi: 10.1016/j.fsi.2016.02.034. Epub 2016 Mar 2.
The present study was conducted to evaluate the effects of different L-alanyl-l-glutamine (Ala-Gln) feeding strategies on the growth performance, metabolism and crowding stress resistance related parameters in juvenile Jian carp (Cyprinus carpio var. Jian) under crowded condition (80 g/L). Juvenile Jian carp (initial weight 26.1 ± 0.6 g) were distributed into five groups which fed with graded concentrations (0% or 1.0%) of Ala-Gln for eight weeks. Control group (I, 0/0) fed with control diet (0% Ala-Gln) throughout the feeding trial. The other four groups employed different control and experimental diet feeding strategies ranging from two weeks control diet fed and two weeks experimental diet (1% Ala-Gln) fed (II, 0/2) to eight weeks experimental diet fed (V, 4/4). Results revealed that Mean weight gain (MEG) under all different feeding strategies of Ala-Gln were significantly higher than that of the control group (p < 0.05), and MEG of group II (201.90%) was even higher than that of group IV (184.70%). Liver glycogen and blood total protein of groups II, III and V were significantly higher than that in groups I and IV (p < 0.05). The highest level of serum thyroxine (10.07 ng/ml), insulin-like growth factor-I (52.40 ng/ml) and insulin (9.73 μ IU/mL) were observed in group V. However, diet supplemented with Ala-Gln did not affect the levels of serum glucose, cortisol and catecholamine in fish. The mRNA expression of GR1a, GR1b and GR2 were also significantly changed in Ala-Gln supplementation groups compared with control group (p < 0.05). After fish intraperitoneally injected with virulent Aeromonas hydrophila, the fish survival rates were significantly increased in all Ala-Gln supplementation groups compared with control group (p < 0.05). Results from the present experiment showed the importance of dietary supplementation of Ala-Gln in benefaction of the growth performance, metabolism and crowding stress resistance in Jian carp breeding. The optimal feeding strategy was alternatively fed with control diet and then experimental diet at an interval of two weeks for juvenile Jian carp under crowded condition.
本研究旨在评估不同L-丙氨酰-L-谷氨酰胺（Ala-Gln）投喂策略对拥挤条件（80 g/L）下建鲤幼鱼生长性能、代谢及抗拥挤应激相关参数的影响。将建鲤幼鱼（初始体重26.1±0.6 g）分为五组，分别投喂不同浓度（0%或1.0%）的Ala-Gln，为期8周。对照组（I，0/0）在整个投喂试验中投喂对照饲料（0% Ala-Gln）。其他四组采用不同的对照和试验饲料投喂策略，从两周对照饲料投喂和两周试验饲料（1% Ala-Gln）投喂（II，0/2）到八周试验饲料投喂（V，4/4）。结果显示，在所有不同的Ala-Gln投喂策略下，平均增重（MEG）均显著高于对照组（p<0.05），且II组的MEG（201.90%）甚至高于IV组（184.70%）。II、III和V组的肝糖原和血液总蛋白显著高于I组和IV组（p<0.05）。V组血清甲状腺素（10.07 ng/ml）、胰岛素样生长因子-I（52.40 ng/ml）和胰岛素（9.73 μIU/mL）水平最高。然而，添加Ala-Gln的饲料并未影响鱼体血清葡萄糖、皮质醇和儿茶酚胺水平。与对照组相比，添加Ala-Gln组的GR1a、GR1b和GR2的mRNA表达也有显著变化（p<0.05）。在建鲤幼鱼腹腔注射嗜水气单胞菌后，所有添加Ala-Gln组的鱼存活率均显著高于对照组（p<0.05）。本实验结果表明，饲料中添加Ala-Gln对建鲤幼鱼的生长性能、代谢及抗拥挤应激有益。对于拥挤条件下的建鲤幼鱼，最佳投喂策略是每隔两周交替投喂对照饲料和试验饲料。
