饲料脂肪水平对芙蓉鲤鲫幼鱼血清生化指标、免疫反应及抗氧化能力的影响

为研究饲料脂肪水平对芙蓉鲤鲫(Furong crucian carp)幼鱼初始体重, (2.040.01) g]血清生化指标、免疫指标及抗氧化能力的影响, 以鱼油为主要脂肪源, 配制五种脂肪水平分别为2.50%、4.39%、6.61%、8.42%和10.81%的等氮实验饲料。实验在室内循环水养殖系统中进行, 每种饲料3个重复, 每个重复随机放养30尾芙蓉鲤鲫, 养殖周期为60d。结果显示: 随着饲料中脂肪水平的升高, 芙蓉鲤鲫增重率和蛋白质效率呈现先显著升高后显著降低的趋势(P0.05), 而饲料系数呈现相反的趋势。饲料脂肪水平升高显著提高了芙蓉鲤鲫血清中总胆固醇(CHO)和球蛋白(GLB)含量, 而显著降低总蛋白(TP)和白蛋白(ALB)含量。饲料脂肪水平未对鱼体血清高密度脂蛋白胆固醇(HDL-C)和甘油三酯(TG)含量造成显著影响(P0.05)。芙蓉鲤鲫血清免疫球蛋白M (IgM)含量、血清和肝胰脏超氧化物歧化酶(SOD)活力、肝胰脏总抗氧化能力(T-AOC)随脂肪水平增加先升高后下降(P0.05)。血清中过氧化氢酶(CAT)活力10.81%组显著高于其他各组(P0.05)。肝胰脏CAT和丙二醛(MDA)活力在各处理组组间差异不显著(P0.05)。研究结果表明, 在饲料中适宜的脂肪添加有助于改善芙蓉鲤鲫健康状况, 但过高的脂肪水平加重了芙蓉鲤鲫的代谢压力和氧化速率。增重率与饲料脂肪水平作二次回归分析显示, 芙蓉鲤鲫获得最大增长所需饲料脂肪最佳水平为6.94%。

EFFECT OF DIETARY LIPID LEVELS ON SERUM BIOCHEMICAL INDICES,IMMUNE RESPONSES AND ANTIOXIDANT CAPABILITY OF JUVENILE FURONG CRUCIAN CARP (FURONG CARP♀× RED CRUCIAN CARP♂)

To investigate effects of dietary lipids on serum biochemical indices, immunity, and antioxidant capability of juvenile Furong crucian carp (Furong carp♀× red crucian carp♂) mean initial body weight, (2.04±0.01) g], five isonitrogenous experimental diets were formulated with increasing lipid levels (2.50%, 4.39%, 6.61%, 8.42%and 10.81%lipid) using fish oil as the lipid source to feed triplicate groups of fish for 60 days. The results showed that with the increase of dietary lipid level, weight gain rate (WGR) and protein efficiency ratio (PER) significantly increased and then decreased, and the maximum of WGR and PER were found in the 6.61%lipid group (P<0.05). The feed conver-sion ratio (FCR) showed the opposite trend. Dietary lipids significantly increased serum total cholesterol (CHO) and globulin (GLB) contents, but significantly decreased total protein (TP) and albumin (ALB) content (P<0.05). Dietary lipids have no effect in high density lipoprotein cholesterol (HDL-C) and triglyceride (TG) content (P>0.05). The im-munoglobulin M (Ig M) content, serum superoxide dismutase (SOD), hepatic SOD activity and total antioxidant capa-city (T-AOC) significantly increased and then decreased with increasing dietary lipid levels (P<0.05). The maximum of serum catalase (CAT) activity was found in the 10.81%lipid group, which are significantly higher than other groups (P<0.05). There were no significant difference in hepatic CAT activity and malondialdehyde (MDA) content among dietary treatments (P>0.05). These results suggest that proper die-tary lipid level can improve the health of Furong crucian carp, but excess dietary lipid may exert adverse effects. Based on the second-order regression analysis of WGR, the optimal dietary lipid level in juvenile furong crucian carp was 6.94%.