实用饲料对养殖草鱼体组织脂肪酸组成的影响

Influence of practical diets on tissue fatty acid composition in reared grass carp(Ctenopharyngodon idellus)

为探究生产一线所使用的实用饲料对养殖草鱼体组织脂肪酸组成的影响,试验对两种草鱼育成期商品饲料(CY1和CY2)及该饲料饲喂草鱼的肝胰脏、腹腔脂肪组织、肾脏、肠道、脾脏、肌肉、鳃、眼、脑9种组织的脂肪酸组成进行了检测和分析。结果显示,CY1和CY2饲料亚油酸(LA)含量分别为35.13%和35.07%,亚麻酸(LNA)含量分别为4.93%和9.01%,花生四烯酸(ARA)含量分别为1.10%和10.88%,n-3高不饱和脂肪酸(HUFA)含量分别为2.12%和0.80%。饲料与组织脂肪酸组成相关性分析显示,腹腔脂肪组织和肠道组织的脂肪酸组成与饲料脂肪酸组成相关系数最高,脑组织最低。为了判明脂肪酸的组织沉积特征,对组织重要脂肪酸含量与饲料相应脂肪酸含量的比值进行散点分析,发现脂肪酸离散程度由高到低依次为HU.FA、LA和LNA、饱和脂肪酸(SFA)和单不饱和脂肪酸(MUFA)。组织及饲料SFA、MUFA、HUFA比值大于1,LA、LNA比值小于1。不同组织器官相比较,腹腔脂肪组织的SFA、HUFA比值最低,MUFA、LA、LNA比值较高;相反,在脑组织中,HUFA比值较高,而LA、LNA比值最低。研究表明,两种商品饲料LNA的添加水平较低,LA的添加水平较高。鱼体组织的脂肪酸组成基本反映了饲料脂肪酸组成,但脂肪酸的组织沉积模式存在差异,分析可能与不同类型脂肪酸的利用与转化特点不同有关。建议生产中有针对性地选择饲料油脂,以满足草鱼生长及维护健康状态的脂肪酸需求。

Two kinds of praetieal grass carp feed （CYI and C32） a,ld 9 tissues （hepalopancreas, intraperitoneal fat, kidney, intestine, spleen, muscle, gill, eyes and brain） of the fish fed with the two kinds of feed were collected to evaluate the influence of practical diets on tissue fatty acid composition in reared grass carp. The results showed that LA eontent in diel CYI and CY2 were 35.13% and 35.07%, respectively, LNA enntent were 4.93% and 9.01%, respeclively. ARA level were 1.10% and 10.88%, respectively, and n-3 HUFA proportion were 2.12＋＇,4＇ and 0.80%, respectively, lntraperitoneal fal and intestine showed the highesl enrrelation coefficient between tissues anti dietary fatty acid cnnlposition, while the brain showed the Inwest correlation coefficient, hnportant fatty acid enntent of the tissue and corresponding dietary fatty acid content ratio were analyzed with seatter diagram to justify the feature of tissue rally acid deposition. Dispersion degree from high Io h,w was HUFA, I,A and I,NA, SFA and MIJFA, respectively. SFA, MUFA and HUF＇A ratios were greater than 1 while LA and LNA ratio were less than 1. Compared Io other lissues, intraperitoneal tat, SFA, HUFA vonlenls were the lowes! and MUFA, LA, I,NA were the highest, on the contrary, in brain, HUFA showed the higher content and LA, LNA showed the lowest content. In conclusion, the dietary LNA content in practical feed appears to be less than the necessary, while the LA content excessive. Tissue fatty acid profiles reflected the composition of dietary fatty acid, however, the fatty acid deposition patterns were different in various tissues, which might be related to the diversity of utilization and transformation mode of certain fatty acid. It is suggested that the attention should be paid for the dietary oil source selection to meet the fatty acid requirement of grass carp, which could be benefit to the growth and health status of this specific fish species.