作 者：
徐良;闻海波;孙光兴;马学艳;金武;华丹;顾若波;徐跑
单 位：
南京农业大学无锡渔业学院;中国水产科学研究院淡水渔业研究中心农业农村部淡水鱼类遗传育种与养殖生物学重点开放实验室;中国水产科学研究院淡水渔业研究中心中美淡水贝类种质资源保护及利用国际联合实验室
关键词：
眼斑拟石首鱼;鱼油;脂肪代谢;脂肪酸;饲料
摘 要：
为了增加眼斑拟石首鱼Sciaenops ocellatus血浆多不饱和脂肪酸(DPA)和二十二碳六烯酸(DHA)含量,筛选适宜而有效的鱼油添加量,在等氮等能饲料基础上添加不同含量的鱼油(4%、7%、9%),饲喂3组体质量为(43.40±6.40)g的眼斑拟石首鱼,每组设3个平行,每个平行放养30尾鱼,养殖试验共进行8周,试验结束后测定3个鱼油添加量水平对鱼体生长、脂肪代谢和血液指标等的影响。结果表明:添加鱼油4%和7%的试验组鱼体存活率、体长、增重率显著高于9%鱼油添加组(P<0.05);4%鱼油添加组肝体指数和脏体指数显著低于9%鱼油添加组(P<0.05),但与7%鱼油添加组无显著性差异(P>0.05);3组的鱼体肥满度均无显著性差异(P>0.05);3组鱼体肠道脂肪酶(LPS)和脂质过氧化物酶(LPO)等活性无显著性差异(P>0.05);肝脏组织学观察显示,肝细胞脂肪变性程度与添加鱼油水平呈正相关;4%和7%鱼油添加组血糖含量显著高于9%鱼油添加组(P<0.05),而4%鱼油添加组谷丙转氨酶(ALT)含量显著低于9%鱼油添加组(P<0.05),但甘油三酯含量则显著高于9%鱼油添加组(P<0.05);3组的总蛋白、总胆固醇及低密度脂蛋白(LDL)无明显差异(P>0.05);4%鱼油添加组DPA和DHA含量分别为(226.72±27.74)、(2470.31±293.51)mg/L,是未添加鱼油的2倍水平,但4%和7%鱼油添加组无显著性差异(P>0.05)。研究表明:饲料中添加过量脂肪(鱼油过多)会抑制眼斑拟石首鱼的生长,并抑制脂肪代谢相关酶,加速肝脏脂肪沉积;在饲料总脂肪8.21%条件下,即添加4%的鱼油(DHA含量24%)可以显著增加眼斑拟石首鱼血浆中DHA和DPA含量。
译 名：
Effects of dietary fish oil levels on growth, lipid metabolism and blood physiology of red drum Sciaenops ocellatus
作 者：
XU Liang;WEN Haibo;SUN Guangxing;MA Xueyan;JIN Wu;HUA Dan;GU Ruobo;XU Pao;Wuxi Fisheries College, Nanjing Agricultural University;Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences;Sino-US Cooperative Laboratory for Germplasm Conservation and Utilization of Freshwater Mollusks, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences;
关键词：
Sciaenops ocellatus;;fish oil;;fat metabolism;;fatty acid;;feed
摘 要：
Juvenile red drum Sciaenops ocellatus with initial body weight of(43.40±6.40)g were reared in 9 net cages(1 m×1 m×1 m) disposed in a cement tank and fed isonitrogen and isoenergetic diets containing 4%(group 4%), 7%(group 7%) and 9%(group 9%) of fish oil at water temperature for 8 weeks when the growth performance, indicators of lipid metabolism, blood parameters and liver histology were investigated in the fish fed the diets containing various levels of fish oil in order to screen the optimal dietary fish oil levels to increase the contents of docosapentaenoic acid and docosahexaenoic acid in the plasma of the red drum. Results showed that there were significantly higher survival rate, body length, and weight gain rate in the fish in groups 4% and 7% fish oil than those in group 9%(P<0.05). The fish fed the diet containing 4% of the fish oil had significantly lower hepatosomatic index and viserosomatic index than the fish fed the diet containing 9% of the fish oil(P<0.05) did, without significant difference between group 4% and group 7%. No significant difference in condition factors and activities of lipase(LPS) and lipoperoxidase(LPO) in intestines were found among the three groups(P>0.05). The liver histological observation revealed that hepatocyte steatosis was positively correlated in extent with the level of dietary fish oil. The blood glucose levels were significantly higher in group 4% and group 7% than that in group 9%(P<0.05), with significantly lower alanine transaminase(ALT) activity in group 4% than that in group 9%(P<0.05). There were significantly higher triglyceride level in group 4% than that in group 9%(P<0.05), without significant differences between group 4% and group 7%, and without significant difference in total protein, total cholesterol and low density lipoprotein(LDL) levels among the three groups(P>0.05). There were(226.72±27.74)mg/L of docosapentaenoic acid and(2470.31±293.51) mg/L of docosahexaenoic acid in group 4%, significantly higher than those in other fishes, without significant difference between group 4% and group 7%(P>0.05). The findings indicated that too much dietary fat(fish oil) inhibited the growth of the red drum, and the activities of enzymes related to fat metabolism, and accelerated the deposition of liver fat, and that the level of docosapentaenoic acid and docosahexaenoic acid in the plasma of the red drum was significantly increased by addition of 4% fish oil with 24% DHA in the commercial feed containing 8.21% crude fat.
