拟微绿球藻粉替代鱼粉对大菱鲆幼鱼生长性能、体组成和血清生化指标的影响

Effects of Replacement of Dietary Fish Meal by Nannochloropsis sp. Meal on Growth Performance, Body Composition, and Serum Biochemical Indices of Juvenile Turbot (Scophthalmus maximus L.)

中文关键词: 大菱鲆  拟微绿球藻粉  生长  抗氧化能力

英文关键词: Juvenile turbot  Nannochloropsis sp. meal  Growth performance  Antioxidant activity

中文摘要:

      为探讨拟微绿球藻(Nannochloropsis sp.)粉替代鱼粉对大菱鲆(Scophthalmus maximus L.)幼鱼生长性能、体组成和血清生化指标的影响，用拟微绿球藻粉替代基础饲料中0%、3.88%、7.76%、11.64%和15.52%的鱼粉，配制成5种等氮等能的饲料(N0、N3.88、N7.76、N11.64、N15.52)。选取初始体重为(24.60 ±0.02) g的大菱鲆幼鱼600尾，随机分成5组，每组3个重复，每个重复40尾鱼，养殖周期70 d。结果显示：1)各实验组大菱鲆幼鱼的增重率(WGR)、特定生长率(SGR)、蛋白质效率 (PER)、饲料系数(FCR)、日摄食率(DFI)、肥满度(CF)和成活率(SR)均无显著差异(P>0.05)；2)随着藻粉添加量的增加，全鱼及肌肉中粗脂肪含量显著降低(P<0.05)，粗蛋白、粗灰分和水分含量无显著差异(P>0.05)；3)血清溶菌酶(LZM)、补体蛋白C3、补体蛋白C4及酸性磷酸酶(ACP)活力均呈先上升后下降的趋势，分别在N7.76、N7.76、N11.64、N7.76组达到最大值，且显著高于N0组(P<0.05)，N15.52组碱性磷酸酶(ALP)显著低于其他组(P<0.05)，其他组之间无显著差异(P>0.05)；4)藻粉组血清总超氧化物歧化酶(T-SOD)、总抗氧化能力(T-AOC)和谷胱甘肽过氧化物酶(GSH-PX)活力，均呈先上升后下降的趋势，在N7.76组达到最大值，且显著高于N0组(P<0.05)；5) N7.76组血清甘油三酯(TG)含量显著低于其他组(P<0.05)，其他组之间无显著差异(P>0.05)，藻粉组血清总胆固醇(TCHO)显著低于N0组(P<0.05)，各藻粉组之间差异不显著(P>0.05)；6)藻粉组血清谷草转氨酶(AST)活力呈先下降后上升的趋势，N11.64组达到最小值，显著低于N0组(P<0.05)，藻粉组谷丙转氨酶(ALT)活力显著低于N0组(P<0.05)。研究表明，本实验条件下，拟微绿球藻粉替代大菱鲆幼鱼饲料中15.52%的鱼粉对其生长无显著影响，替代7.76%可显著提高其非特异性免疫力，降低血脂水平。

英文摘要:

      A 70-day trial was conducted to investigate the effect of replacement of dietary fish meal by Nannochloropsis sp. meal on growth performance, body composition, and serum biochemical indices of juvenile turbot Scophthalmus maximus L. with an initial weight body weight of (24.60±0.02) g. Five isonitrogenous and isoenergetic diets (N0, N3.88, N7.76, N11.64, and N15.52) were formulated with 0%, 3.88%, 7.76%, 11.64%, and 15.52% fish meal replaced by Nannochloropsis sp. meal, respectively. Each diet was randomly fed to three replicates of fish, with 40 fish per replicate. The following results were obtained. 1) There were no significant differences (P>0.05) in weight growth rate, specific growth rate, protein efficiency ratio, feed coefficient ratio, feed intake, condition factor, and survival rate among the groups. 2) As the meal content of Nannochloropsis sp. increased, the crude lipid content in the whole body and muscle was significantly decreased (P<0.05); however the crude protein, crude ash, and moisture content were not significantly different (P>0.05). 3) Lysozyme, complement protein C3, complement protein C4, and acid phosphatase activities showed a rising trend followed by a decline, with the highest point reached in the N7.76, N7.76, N11.64, and N7.76 groups, respectively, and were significantly higher than that in the N0 group (P<0.05). The alkaline phosphatase activity of the N15.52 group was significantly lower than that the other groups and there were no significant differences among other groups (P>0.05). 4) The total superoxide dismutase, total antioxidant capacity, and glutathione peroxidase activities in the serum of the algae meal groups first increased and then decreased, and reached a maximum in the N7.76 group, which was significantly higher than that in the N0 group (P<0.05). 5) The triglyceride content in the serum of the N7.76 group was significantly lower than that in the other groups (P<0.05), and there were no significant differences among the other groups (P>0.05). The total cholesterol content of the algae meal groups was significantly lower than in the N0 group (P<0.05), but there were no significantly differences among the algae meal groups. 6) The aspartate aminotransferase activity in the serum of the algae meal groups followed a decreasing to increasing trend, reaching the lowest point in the N11.64 group and was significantly lower than that in the N0 group (P<0.05). The alanine aminotransferase activity of the algae meal groups was significantly lower than that in the N0 group (P<0.05). In conclusion, under the experimental conditions tested, Nannochloropsis sp. meal could replace 15.52% of fish meal in juvenile turbot feed without any effects on the growth performance, and the replacement of 7.76% fish meal significantly improved the nonspecific immunity and reduced the blood lipid levels in juvenile turbot.