磷脂影响日本沼虾对饲料中脂肪的需要量

Phospholipid Affects Dietary Lipid Requirement of Oriental River Prawn ( Macrobrachium nipponensis)

本试验旨在探讨饲料中磷脂对日本沼虾(Macrobrachium nipponense)脂肪需要量的影响。选取初始体重为(0.075±0.001)g的日本沼虾为试验对象,在室内养殖缸中进行为期8周的生长试验。将鱼油和豆油等比例混合均匀,再与大豆磷脂分别按2∶1和1∶2混合,使得大豆磷脂分别占脂类混合物的33.3%(低磷脂组)和66.7%(高磷脂组)。将2种脂类混合物分别按3%(低脂肪组)、6%(中脂肪组)、9%(高脂肪组)的比例添加到饲料中,配制出6种等氮等能的试验饲料。根据试验饲料中脂类混合物添加量和大豆磷脂添加量,将6种试验饲料分别命名为L3P1、L3P2、L6P2、L6P4、L9P3、L9P6,实测试验饲料中脂肪水平分别为7%、7%、10%、10%、13%、13%。每种试验饲料投喂4缸试验虾,每缸放养150尾。结果表明:6组日本沼虾的成活率在47.8%~66.9%,以L6P4组成活率最高,其次是L3P2组,以L9P3组最低。高脂肪组的终末体重、增重率、特定生长率和成活率显著低于中、低脂肪组(P<0.05),饲料系数显著高于中、低脂肪组(P<0.05)。高磷脂组终末体重、增重率、特定生长率和成活率显著高于低磷脂组(P<0.05),饲料系数显著低于低磷脂组(P<0.05)。脂类混合物添加量和大豆磷脂比例对各生长性能指标均有显著的交互作用(P<0.05)。虾体粗脂肪含量随着饲料脂肪水平的升高而显著升高(P<0.05),但高磷脂组虾体粗脂肪含量显著低于低磷脂组(P<0.05)。高脂肪组肝胰腺类胰蛋白酶和脂肪酶活性显著低于中、低脂肪组(P<0.05);高磷脂组肝胰腺脂肪酶活性显著高于低磷脂组(P<0.05)。脂类混合物添加量和大豆磷脂比例对肝胰腺脂肪酶活性有显著的交互作用(P<0.05)。脂类混合物添加量对肝胰腺超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC)有显著影响(P<0.05),而大豆磷脂比例对二者无显著影响(P>0.05),但脂类混合物添加量和大豆磷脂比例对肝胰腺T-AOC有显著的交互作用(P<0.05)。上述结果提示,日本沼虾饲料中磷脂应与脂肪保持一定的比例。根据本试验结果,饲料中脂肪水平为10%、大豆磷脂添加量为4%时对日本沼虾比较适宜。

This experiment was carried out to investigate the effects of dietary phospholipid on the requirement of lipid for oriental river prawn(Macrobrachium nipponensis).The oriental river prawns with the initial body weight of(0.075±0.001)g were fed in indoor tanks and fed experimental diets for 56 days.Fish oil and soybean oil was mixed with the equal proportion first.Next,soybean phospholipid was mixed into the mixture of fish oil and soybean oil at the ratio of 33%(low-phospholipid group)and 67%(high-phospholipid group),respectively,then each lipid mixture was supplemented into diet at 3%(low-lipid group),6%(middle-lipid group)and 9%(high-lipid group),respectively,to formulate six isonitrogenous and isoenergetic diets,which were named as L3P1,L3P2,L6P2,L6P4,L9P3 and L9P6 according to the additions of lipid mixture and soybean phospholipid,and the measured lipid level in those diets was 7%,7%,10%,10%,13%and 13%,respectively.Each diet was fed 4 tanks and each tank cultured 150 shrimps.The results showed that the survival rate of shrimps in six groups ranged from 47.8%to 66.9%.Among them,the survival rate of shrimps in L6P4 group was the highest,followed by L3P2 group,and the lowest in L9P3 group.The final body weight,weight gain rate,specific growth rate and survival rate in the high-lipid group were significantly lower than those in the middle-and low-lipid groups(P<0.05),and the feed conversion ratio was significantly higher than that in the middle-and low-lipid groups(P<0.05).The final body weight,weight gain rate,specific growth rate and survival rate in the high-phospholipid group were significantly higher than those in the low-phospholipid group(P<0.05),and the feed conversion ratio was significantly lower than that in the low-phospholipid group(P<0.05).The addition of lipid mixture and the proportion of soybean phospholipid had significant interactions in growth performance indexes of shrimps(P<0.05).Body ether extract content was significantly increased with dietary lipid level increasing(P<0.05),however,the body ether extract content of shrimps in the high-phos-pholipid group was significantly lower than that in the low-phospholipid group(P<0.05).The activities of trypsin and lipase in hepatopancreas of shrimps in high-lipid group was significantly lower than that in middle-and low-lipid groups(P<0.05);the activity of lipase in hepatopancreas of shrimps in high-phospholipid group was significantly higher than that in low-phospholipid group(P<0.05),and a significant interaction between the addition of lipid mixture and the proportion of soybean phospholipid was detected(P<0.05).The activities of superoxide dismutase(SOD)and total antioxidant capacity(T-AOC)in hepatopancreas of shrimps were in-fluenced by the addition of lipid mixture(P<0.05),but the proportion of soybean phospholipid had no signifi-cant effects on them(P>0.05).However,the addition of lipid mixture and proportion of soybean phospholipid had a significant interaction in hepatopancreas T-AOC(P<0.05).These results indicate that phospholipid should be kept in a proper proportion with lipid in the diet,and it is relative optimal when the dietary lipid level is 10%and the phospholipid addition is 4%for oriental river prawn.