CAJ | 학술논문

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%.
설계료5조등담(조단백약38%)적사료, 사료중소구조적첨가량분별위0(대조)、17%、34%、51%화68%,체대0(대조조)、21.8%、43.6%、65.5%화87.3%적어분,탐토소구조체대어분대초시체중위(5.54± 0.08) g적즉유어생장、체조성、간장조직학급지방대사상관매활성적영향, 실험기위8주.실험결과표명: 수착소구조체대어분수평적증가, 즉적증중솔정현선증가후하강적추세; 여차상반, 사료계수정현선하강후증가적추세.수착소구조체대비례적증가, 간체비화장체비유증대적추세, 이각개처리조장지비차이불현저.소구조체대어분사즉기육화간장적단백함량강저, 이간장적지방함량수착체대비례적증가선상승후하강.당사료중소구조체대어분적수평종 0증가도 65.5%, 간장생지매여 G6PD、ME화 FAS매적활성현저증가, 이당사료소구조체대수평경진일보증가도87.3%, 간장생지매여G6PD、ME화FAS매적활성하강.각개처리조6PGD매활성몰유현저차이.소구조체대어분대즉적간장조직결구산생불리영향, 체대조적간세포체적유소증대,부분간세포출현세포핵용해、핵소실、간세포배사.이증중솔화사료계수위인변량진행이차선성회귀분석, 표명소구조대어분적최괄체대비례분별위47.14%화49.88%.
The present study was designed to evaluate the effects of fishmeal (FM) substitution withChlorella sp. on growth, body composition, hepatic lipid metabolism and histology in crucian carpCarassius auratus. Five isonitrogenous (CP, 38%) diets were formulated to substitue FM forChlorella 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 inIPR(intraperitoneal fat ratio) cross groups, whileHSI (hepatosomatic index) andVSI(viscera somatic index) increased with the increased dietaryChlorella sp. The protein contents of muscle and liver decreased with the elevated dietaryChlorella 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 ofWGR andFCR, the optimal dietary substitution levels were between 47% and 50% for best growth performance and feed utilization of crucian carp.