饲料脂肪水平对美国红鱼生长性能、体组成和肝脏组织结构的影响

Effects of Dietary Lipid Level on Growth Performance,Body Composition and Liver Histological Structure of Red Drum( Sciaenops ocellatus)

通过57 d的养殖试验评估饲料脂肪水平对美国红鱼（Sciaenops ocellatus）生长性能、体组成、肝脏组织结构的影响。共配制蛋白质水平为47%,脂肪水平分别为7.19%、9.17%、10.94%、13.04%和14.20%的5种等氮饲料,每种饲料设4个重复,每个重复饲养30尾美国红鱼[初始体重（19.88±0.26）g]。结果显示：7.19%组的末均重、增重率、特定生长率显著高于13.04%、14.20%组（P〈0.05）,但3个低水平组（7.19%、9.17%、10.94%组）间差异不显著（P〉0.05）;蛋白质效率随饲料脂肪水平的升高而下降;与之相反,饲料系数呈上升趋势,其中7.19%、9.17%组显著低于13.04%、14.20%组（P〈0.05）;此外,13.04%、14.20%组的脏体比、肠脂比显著大于其他3组（P〈0.05）。全鱼、肝脏的粗脂肪含量随饲料脂肪水平的升高而持续上升,以7.19%组最低;而全鱼粗蛋白质含量则以9.17%组最高。肝脏组织学检查显示,各组试验鱼发生肝细胞脂肪变性的程度与饲料脂肪水平呈正相关。综上所述,美国红鱼人工配合饲料中脂肪的推荐水平为7.19%-9.17%。

A 57-day feeding experiment was conducted to determine the effects of dietary lipid level on growth performance,body composition and liver histological structure of red drum（ Sciaenops ocellatus）. Five isonitrogenous diets（ contained 47% crude protein） were designed to contain five dietary lipid levels（ 7. 19%,9.17%,10.94%,13.04%,14.20%,respectively）,and each diet was randomly assigned to 4 replicates of 30 red drum [average body weight of（ 19.88 ± 0. 26） g]. The results showed that the final average body weight（ FBW）,weight gain rate（ WGR） and specific growth rate（ SGR） in the 7.19% group were significantly higher than those in the 13.04% and 14.20% groups（ P〈 0.05）,and no significant differences were found among the three lower level groups（ 7. 19%,9. 17% and 10. 94% groups）. W ith the increase of dietary lipid level,the protein efficiency ratio（ PER） showed a descending trend,while conversely the feed conversion ratio（ FCR） showed a rising tendency,and the FCR in the 7.19% and 9.17% groups was significantly lower than that in the 13.04% and 14.20% groups（ P〈 0.05）. Moreover,viscerasomatic index（ VSI） and mesenteric fat index（ MFI） in the 13.04% and 14.20% groups were significantly higher than those in the other three groups（ P〈 0.05）. Lipid content in whole body and liver was increased with the increase of dietary lipid level,which of 7.19% group came to be the lowest,though the crude protein content in whole body of 9.17% group seemed to be the highest. Histological examinations indicated that the severity of fatty degeneration in liver cells of red drum had a positive relationship with the dietary lipid level. In conclusion,the dietary lipid level in artificial formulated feed for red drum is recommended to be 7.19% to 9.17%.