发酵南极磷虾粉替代鱼粉对锦鲤生长、体色及血清生化指标的影响

Effects of Fish Meal Replacement with Fermented Antarctic Krill Meal on Growth Performance,Body Color and Serum Biochemical Indexes of Koi Carp(Cyprinus carpio L.)

为探讨发酵南极磷虾(Euphausia superba)粉替代鱼粉对锦鲤(Cyprinus carpio L.)生长、体色和血清生化指标的影响,以初始体质量为(4.92±0.22)g的锦鲤450尾为实验对象,随机分为5组,每组设置3个重复,每个重复30尾鱼,对照组添加未发酵的脱脂南极磷虾粉,实验组添加由粪肠球菌(Enterococcus faecalis)、植物乳杆菌(Lactobacillus plantarum)、丁酸梭菌(Clostridium butyricum)和复合菌(1∶1∶1)发酵的脱脂南极磷虾粉,分别命名为ES(对照组)、EF、LP、CB和MIX,南极磷虾粉的添加量均为200 g/kg,共投喂70 d。结果表明,与对照组相比,发酵南极磷虾粉替代鱼粉显著提高了锦鲤的终末体质量、特定生长率和增重率(P<0.05),MIX组的终末体质量、特定生长率和增重率显著高于其他组(P<0.05)。实验组皮肤和鳞片中类胡萝卜素含量显著增加(P<0.05),红色(a*)值、黄色(b*)值以及tyr在皮肤和鳞片中相对表达量显著提高(P<0.05),MIX组的a*值、b*值和基因相对表达量显著高于其他组(P<0.05)。实验组血清甘油三酯(TG)和总胆固醇(TC)含量均显著提高(P<0.05),谷草转氨酶/谷丙转氨酶(AST/ALT)比值和丙二醛(MDA)含量显著下降(P<0.05)。对照组锦鲤肝细胞出现脂滴和空泡化现象。研究表明,在脱脂磷虾粉添加水平为20%的锦鲤饲料中,使用复合菌对磷虾粉进行发酵能有效提高磷虾粉的吸收和转化利用率。

To investigate the effects of replacing fish meal with fermented Antarctic krill meal on growth performance,body color,and serum biochemical indexes of koi carp,450 koi carp with an average body weight of(4.92±0.22)g were randomly divided into five groups with three replicates per group and 30 fish per replicate.In the control group,we added unfermented defatted Antarctic krill meal,and in the experimental groups,we added defatted Antarctic krill meal fermented by Enterococcus faecalis,Lactobacillus plantarum,Clostridium butyricum,and compound bacteria(1:1:1),which were termed as ES(control group),EF,LP,CB,and MIX,respectively.The addition amount of Antarctic krill meal in each group was 200 g/kg,and the experiment lasted for 70 days.The results showed the following:Compared with those in the control group,the replacement of fish meal with fermented Antarctic krill meal significantly improved final body weight(FBW),weight gain rate(WGR),and specific growth rate(SGR)(P<0.05);additionally,the FBW,WGR,and SGR of the MIX group were significantly higher than those in other groups(P<0.05).The carotenoid content in the skin and scales of the experimental group was significantly increased(P<0.05);the red(a*)and yellow(b*)value,and relative expression of tyr in the skin and scales were significantly increased(P<0.05);and the a*and b*values and the relative expression of the tyr gene in the MIX group were significantly higher than those in other groups(P<0.05).The contents of serum triglyceride(TG)and total cholesterol(TC)in the experimental group were significantly increased(P<0.05),whereas the ratio of glutamic oxalate transaminase/alanine transaminase(AST/ALT)and the content of malondialdehyde(MDA)were significantly decreased(P<0.05).The liver cells of the control group showed lipid droplets and vacuolar degeneration.No significant difference was observed in each index among the EF,LP,and CB groups(P>0.05).Based on the above results,using complex bacteria to ferment krill meal in the koi carp feed is recommended with a 20%addition level of defatted krill meal,which can effectively improve the absorption and conversion utilization rate of krill meal.