饲料脂肪水平对异育银鲫生长性能、体脂沉积、肌肉成分及消化酶活性的影响

Effects of Dietary Lipid Levels on Growth Performance,Body Fat Deposition,Muscle Composition and Activities of Digestive Enzymes of Gibel Carp (Carassius auratus gibelio)

本试验旨在研究饲料脂肪水平对异育银鲫(Carassius auratus gibelio)生长性能、体脂沉积、肌肉成分和消化酶活性的影响。选取平均重为(17.00±0.15)g的异育银鲫375尾,随机分为5组,每组3个重复,每个重复25尾,分别饲喂在基础日粮中添加0(D0组,即对照组)、2%(D1组)、4%(D2组)、6%(D3组)、8%(D4组)(实测脂肪水平分别为2.16%、4.08%、6.04%、7.99%和9.88%)鱼油的试验日粮。预试期10d,正试期45d。结果表明,随着饲料中脂肪水平的升高,异育银鲫的特定生长率、饲料转化率、肝体指数和肌肉中脂肪含量均呈现先升高后下降的趋势,而肝胰脏中脂肪含量呈现升高趋势。回归模型分析表明异育银鲫达到最优特定生长率、饲料转化率、肝体指数和肌肉中脂肪含量的饲料脂肪水平分别为5.08%、6.92%、7.77%和9.40%。饲料脂肪水平对鱼体肌肉中水分、灰分、磷、钠、镁、铁和锌的含量无显著影响(P>0.05),但可使鱼体肌肉中蛋白质含量呈下降趋势,且当饲料脂肪水平为9.88%时,肌肉中蛋白质含量较对照组显著下降(P<0.05)。饲料中适宜脂肪水平可促进肠道蛋白酶的分泌,而对肠道淀粉酶和肝胰脏蛋白酶、淀粉酶无明显促分泌作用。经生产性能、鱼体品质(体脂沉积、肌肉成分)和消化酶活性等综合分析表明异育银鲫鱼种日粮中适宜脂肪水平为4.08%～6.92%。

The trial was conducted to evaluate the effects of dietary lipid levels on growth performance,body fat deposition,muscle composition and activities of digestive enzymes of gibel carp （Carassius auratus gibelio）. Three hundred and seventy-five juvenile gibel carp with average initial body weight of （17.00±0.15） g were randomly divided into 5 groups （named D0 to D4） with 3 replicates of 25 fish in each replicate. Five groups were fed diets with 0 （group D0,control group）,2% （group D1）,4% （group D2）,6% （group D3） and 8% （group D4） fish oil,respectively （measured lipid levels of 5 diets were 2.16%,4.08%,6.04%,7.99% and 9.88%,respectively）. The experiment lasted for 55 days,including preset period for 10 days and test period for 45 days. The results showed as follows： with the increased of dietary lipid levels,the specific growth ratio,feed conversion ratio,liver somatic index and lipid content in muscle were firstly increased and then decreased,and the lipid content in hepatopancreas was increased. The regression model analysis showed the best dietary lipid level which could acquire the best specific growth ratio,feed conversion ratio,liver somatic index and lipid content in muscle was 5.08%,6.92%,7.77% and 9.40%,respectively. The dietary lipid levels had no significant effects on moisture,ash,sodium,phosphorus,magnesium,iron and zinc content in muscle （P〉0.05）,but there was a downward trend in muscle protein content,and when the dietary lipid level was 9.88%,the protein content in muscle was significantly lower than that in control group （P〈0.05）. The suitable lipid levels in diet could promote the intestinal proteases secretion,and there was no significant role in promoting secretion of the intestinal amylase and hepatopancreas amylase,protease. From basis on comprehensive analysis on growth performance,fish body quality （muscle fat deposition and muscle composition） and activities of digestive enzymes,and it was concluded that the suitable dietary lipid level for gibel carp fingerling should be 4.08%-6.92%.