饲料不同n-3/n-6脂肪酸比值对日本沼虾生长、虾体组分、血清抗氧化及相关基因表达的影响

为探讨饲料中n-3/n-6脂肪酸比值对日本沼虾生长性能、虾体肉质及血清抗氧化能力的影响,设计了5种不同n-3/n-6脂肪酸比值(D1:0.29、D2:0.56、D3:1.02、D4:2.20、D5:8.52)的等氮等脂饲料,进行了8周养殖实验,每组设4个重复,每个重复45尾虾。结果显示,饲料n-3/n-6脂肪酸比值对日本沼虾的存活率(SR)无显著影响;日本沼虾增重率(WGR)和特定生长率(SGR)随饲料脂肪酸比值的增加先升后降,D3组最高且显著高于D1组。饲料n-3/n-6脂肪酸比值对虾体粗脂肪(CF)和粗蛋白(CP)影响显著,D4组虾体粗脂肪显著高于其他各组;D3组虾体粗蛋白显著高于D2、D4和D5组。虾体肌肉脂肪酸比值受饲料脂肪酸比值的影响,肌肉中n-3/n-6脂肪酸比值与饲料中n-3/n-6脂肪酸比值存在显著的正相关关系。血清超氧化物歧化酶(SOD)在D5组达到最高且显著高于D1、D2和D3组,但与D4组差异不显著;D3组谷胱甘肽过氧化物酶(GSH-Px)最高且显著高于其他各组;D5组血清丙二醛(MDA)含量显著高于D1和D3组。饲料脂肪酸比值对日本沼虾肝胰腺抗氧化基因表达影响显著,D4组Hsp60表达量最高且显著高于D5组,但与D1、D2和D3组差异不显著;D2组Hsp70和Toll表达量最高且显著高于其他各组;D5组Myd88表达量最高且显著高于其他各组。综上所述,饲料中n-3/n-6脂肪酸比值为1.02～2.20,可以显著提高日本沼虾的生长性能和非特异性免疫力。

Effects of dietary n-3/n-6 fatty acid ratio on growth performance, body composition, serum antioxidant capacity and related genes expression of oriental river prawn (Macrobrachium nipponense)

An 8-week feeding trial was conducted to study the effect of dietary n-3/n-6 fatty acid ratios on growth performance, body composition and serum antioxidant capacity of oriental river prawn (Macrobrachium nipponense). Five isonitrogenous and isolipid diets with different n-3/n-6 fatty acid ratios (D1: 0.29, D2: 0.56, D3: 1.02, D4: 2.20, D5: 8.52) were formulated to feed five groups of shrimps, respectively. Each diets was fed 4 tanks (4 replicates) with 45 prawns per tank.The results showed as follows: the survival rate of M. nipponensis was not significantly affected by n-3/n-6 fatty acid ratio in diet. The WGR and SGR of the prawns increased first and then decreased with the increasing dietary fatty acid ratios, and the WGR and SGR in D3 group was the highest and significantly higher than those of D1 group. The dietary n-3/n-6 fatty acid ratio had significant influence on the crude fat (CF) and crude protein (CP) of the whole body, and the crude fat reached the maximum value in D4 group, which was significantly higher than those in other groups. The crude protein of whole body in D3 group was significantly higher than those in D2, D4 and D5 groups. The n-3/n-6 fatty acid ratio in muscle was significantly positively correlated with the dietary n-3/n-6 fatty acid ratio. The serum superoxide dismutase (SOD) in D5 group was the highest, which was significantly higher than those in groups D1, D2 and D3, and not significantly different from that in group D4. Glutathione peroxidase (GSH-Px) reached its highest in D3 group, significantly higher than those in other groups. Serum malondialdehyde (MDA) was the highest in D5 group, which was significantly higher than those in D1 and D3 groups. The Hsp60 expression was the highest in group D4 and significantly higher than that in group D5, but not significantly different from groups D1, D2 and D3. The highest expression levels of Hsp70 and Toll in D2 group were significantly higher than those in other groups. Myd88 expression was the highest in D5 group and significantly higher than those in other groups. In conclusion, the dietary n-3/n-6 fatty acid ratio 1.02-2.20 can significantly improve the growth performance and non-specific immunity of M. nipponensis, and change the normal components and fatty acid composition of the prawn whole body.