摘要
设计了5组等氮(粗蛋白约38%)的饲料,饲料中小球藻的添加量分别为0(对照)、17%、34%、51%和68%,替代0(对照组)、21.8%、43.6%、65.5%和87.3%的鱼粉,探讨小球藻替代鱼粉对初始体重为(5.54±0.08)g的鲫幼鱼生长、体组成、肝脏组织学及脂肪代谢相关酶活性的影响,实验期为8周。实验结果表明:随着小球藻替代鱼粉水平的增加,鲫的增重率呈现先增加后下降的趋势;与此相反,饲料系数呈现先下降后增加的趋势。随着小球藻替代比例的增加,肝体比和脏体比有增大的趋势,而各个处理组肠脂比差异不显著。小球藻替代鱼粉使鲫肌肉和肝脏的蛋白含量降低,而肝脏的脂肪含量随着替代比例的增加先上升后下降。当饲料中小球藻替代鱼粉的水平从0增加到65.5%,肝脏生脂酶如G6PD、ME和FAS酶的活性显著增加,而当饲料小球藻替代水平更进一步增加到87.3%,肝脏生脂酶如G6PD、ME和FAS酶的活性下降。各个处理组6PGD酶活性没有显著差异。小球藻替代鱼粉对鲫的肝脏组织结构产生不利影响,替代组的肝细胞体积有所增大,部分肝细胞出现细胞核溶解、核消失、肝细胞坏死。以增重率和饲料系数为因变量进行二次线性回归分析,表明小球藻对鱼粉的最适替代比例分别为47.14%和49.88%。
The present study was designed to evaluate the effects of fishmeal(FM)substitution with Chlorella sp.on growth,body composition,hepatic lipid metabolism and histology in crucian carp Carassius auratus.Five isonitrogenous(CP,38%)diets were formulated to substitue FM for Chlorella sp.with 0(control),21.8%(RM 21.8),43.6%(RM 43.6),65.5%(RM 65.5)and 87.3%(RM 87.3),respectively.Each experimental diet was randomly fed to triplicate groups with 20 crucian carp[initial body weight of(5.54±0.08)g]per tank for 8 weeks.Weight gain rate(WGR)increased with the substitution level from 0 to 43.6%,and then tended to decline with further increased replacement,but feed conversion ratio(FCR)showed the opposite trend with WGR.No significant differences were observed in IPR(intraperitoneal fat ratio)cross groups,while HSI(hepatosomatic index)and VSI(viscera somatic index)increased with the increased dietary Chlorella sp.The protein contents of muscle and liver decreased with the elevated dietary Chlorella sp.level,while the highest hepatic lipid contents were observed in RM 43.6 and RM 65.5 groups,which is associated with the increased expression of several lipogenic enzymes,such as G6PD(glucose-6-phosphate dehydrogenase),ME(malic enzyme),FAS(fatty acid synthase).Chlorella sp.had adverse effects on hepatic histology based on the cell size.Karyolysis,nucleus disappearance or necrosis occured in some hepatocytes of crucial carp fed Chlorella-added diets.Based on the quadratic regression analysis of WGR and FCR,the optimal dietary substitution levels were between 47%and 50%for best growth performance and feed utilization of crucian carp.
作者
石西
罗智
黄超
朱晓鸣
刘胥
SHI Xi;LUO Zhi;HUANG Chao;ZHU Xiao-Ming;LIU Xu(College of Fisheries,Huazhong Agricultural University,Wuhan 430070,China;State Key Laboratory of Freshwater Ecologyand Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;Panjin Guanghe Crab Lid.,Co.,Panjin 124200,China)
出处
《水生生物学报》
CAS
CSCD
北大核心
2015年第3期498-506,共9页
Acta Hydrobiologica Sinica
基金
农业部公益性行业(农业)科研专项(201303053)资助
关键词
鲫
小球藻
鱼粉
生长性能
脂肪代谢
Crucian carp Carassius auratus
Chlorella sp.
Fishmeal
Growth performance
Lipid metabolism
