饲料脂肪水平对许氏平鲉脂肪沉积、血液生化指标及脂肪代谢酶活性的影响

以鱼油为脂肪源,分别配制脂肪水平为3.7%、6.8%、9.6%、13.1%、15.6%的5种实验饲料,对平均初始体质量为(7.13±0.03)g的许氏平鲉进行为期60 d的饲养实验,探讨饲料脂肪水平对许氏平鲉形体指数、脂肪沉积、血液生化指标与脂肪代谢酶活性的影响。结果表明:肝体指数、脏体指数随着饲料脂肪水平的升高显著提高(P0.05),脂肪水平对肥满度没有显著影响(P0.05);许氏平鲉鱼体脂肪沉积随饲料脂肪水平的增加显著提高(P0.05),15.6%全鱼、肌肉、肝脏脂肪含量最高,显著高于3.7%、6.8%组(P0.05)。随着脂肪添加量的增加,许氏平鲉肝脏葡萄糖-6-磷酸脱氢酶(G6PDH)和苹果酸脱氢酶(MHD)活性显著降低(P0.05),15.6%与13.1%组G6PDH、MHD活性显著低于3.7%和6.8%组(P0.05);肝酯酶(HL)和脂蛋白酯酶(LPL)活性显著升高(P0.05),15.6%与13.1%组HL和LPL活性显著高于3.7%和6.8%组(P0.05)。血液甘油三酯(TG)和总胆固醇(CHO)含量随着饲料脂肪水平增加有下降的趋势,15.6%组的TG和CHO含量显著低于3.7%和6.8%组(P0.05);血液中高密度脂蛋白胆固醇(HDLC)、谷草转氨酶(AST)、谷丙转氨酶(ALT)与碱性磷酸酶(ALP)活性呈上升趋势(P0.05),15.6%组最高;低密度脂蛋白胆固醇(LDLC)呈先上升后下降的趋势(P0.05)。研究表明,饲料脂肪水平对许氏平鲉形体指数、脂肪沉积、血液生化指标及脂肪代谢酶活性影响显著,但过高的脂肪水平将使许氏平鲉肝脏脂肪沉积增多,当饲料脂肪水平高于9.6%时不利于鱼类健康生长。

Effects of dietary lipid level on lipid deposition,blood biochemistry indices and lipid metabolic enzyme activities of Sebastes schlegeli

We evaluated the effects of dietary lipid levels on body index,lipid deposition,blood biochemistry indices and lipid metabolic enzyme activities of Sebastes schlegeli.Juvenile fishaverage initial body weight:(7.13±0.03)g]were randomly divided into 5 groups and fed diets containing different lipid levels(3.7%,6.8%,9.6%,13.1% and 15.6%)using fish oil as the lipid source for 60 d.The results showed that the hepatosomatic index(HSI)and viscerosomatic index(VSI)of S.schlegeli increased with increasing dietary lipid levels(P<0.05),while the condition factor(CF)had no significant differences among groups(P<0.05).The crude lipid content of whole body,muscle and liver of S.schlegeli increased with increasing dietary lipid levels(P<0.05).The crude lipid contents of whole body,muscle and liver in the group fed 15.6% lipid were significantly higher than those of the groups fed 3.7% and 6.8% lipid(P<0.05).Dietary lipid had a significant effect on lipid metabolic enzymes(P<0.05).The activities of hepatic glucose-6-phosphate dehydrogenase(G6PDH)and malic dehydrogenase(MDA)decreased with increasing lipid level,but the activities of lipoprotein lipase(HPL)and hepaticlipase(HL)increased(P<0.05).The activities of G6PDH and MDA were significantly lower in the groups fed 15.6% and 13.1% lipid than those of the groups fed 3.7% and 6.8% lipid(P<0.05),but the activities of HPL and HL were significantly higher(P<0.05).The contents of blood triglyceride(TG)and cholesterol(CHO)decreased with increasing dietary lipid levels,but the contents of blood high density lipoprotein cholesterol(HDL-C),glutamic oxaloacetic transaminase(AST)and glutamic pyruvic transaminase(ALT)increased(P<0.05).The contents of blood TG and CHO in the group fed 15.6% lipid were significantly lower than those of the groups fed 3.7% and 6.8% lipid(P<0.05),but the contents of blood HDL-C,AST and ALT were highest.The contents of blood low density lipoprotein cholesterol(LDL-C)initially increased with increasing lipid levels,but then decreased(P<0.05).Results of the above show that dietary lipid level had significant effects on body index,lipid deposition,blood biochemistry indices and lipid metabolic enzyme activities of S.schlegeli,but when dietary lipid level exceeds 9.6%,the lipid deposition in liver would increase,which is bad for health and growth of S.schlegeli.