包膜蛋氨酸对松浦镜鲤生长性能、肠道消化酶和肌肉氨基酸组成的影响

Effects of Coated Methionine on Growth Performance, Intestinal Digestive Enzymes and Muscle Amino Acids Content of Songpu Mirror Carp(Cyprinus carpio Songpu)

试验旨在研究不同水平包膜蛋氨酸(Methionine,Met)对松浦镜鲤(Cyprinus carpio Songpu)幼鱼生长性能、肠道消化酶活性、体组成和肌肉氨基酸组成的影响。选取松浦镜鲤幼鱼360尾,初始体重(8.25±0.78)g,随机分成4组,每组3个重复,每个重复30尾,放养在12个养殖桶中。对照组饲喂添加0.4%晶体Met的基础饲料,试验组分别饲喂0(B0组)、0.2%(B2组)、0.4%(B4组)的包膜Met水平的等氮等能饲料,试验期8周。结果表明:(1)与对照组相比,B0组的增重率和蛋白质效率显著降低(P<0.05),饲料系数显著增加(P<0.05),特定生长率没有显著性差异(P>0.05);与对照组相比,B2、B4组特定生长率、增重率、蛋白质效率和饲料系数均差异不显著(P>0.05)。(2)各组间鱼体水分、粗脂肪、粗灰分含量均无显著差异(P>0.05);与对照组相比,B2组的粗蛋白含量显著降低(P<0.05),B0、B4组无显著差异(P>0.05);B4组的鱼体粗蛋白含量显著高于B0组和B2组(P<0.05)。(3)各组间的胰蛋白酶活性均无显著差异(P>0.05)。B0组淀粉酶活性显著高于对照组和B4组(P<0.05);B4组淀粉酶活性与对照组相比差异不显著(P>0.05),B4组的脂肪酶活性显著高于对照组(P<0.05)。(4)各组间的肌肉必需氨基酸、非必需氨基酸、总氨基酸含量和必需氨基酸指数差异不显著(P>0.05)。说明饲料中添加晶体Met和包膜Met对鲤鱼具有促生长的作用。综合生长性能、消化酶活性及肌肉氨基酸含量分析得出,包膜Met添加量为0.2%可达到晶体Met 0.4%的效果。

This experiment was conducted to investigate the effects of different levels of coated methionine (Met) on growth performance,intestinal digestive enzyme activities,body composition and muscle amino acid composition of juvenile Songpu mirror carp (Cyprinus carpio Songpu).A total of 360 juvenile Songpu mirror carps with an initial body weight of (8.25±0.78) g were randomly divided into four groups,with three tanks per group and 30 fishes per tank.The Control group was fed with basal diet supplemented with 0.4%crystal methionine,and the experimental groups were fed with isonitrogenous and isoenergetic diets containing 0 (B0),0.2%(B2)and 0.4%(B4) coated methionine,respectively.The experiment lasted for eight weeks.The results showed as the followings:(1) Compared with the control group,weight gain rate (WGR) and protein efficiency ratio (PER) in group B0 were significantly decreased (P<0.05),feed conversion ratio(FCR) was significantly increased (P<0.05),and specific growth rate (SGR) was not significantly different(P>0.05);there were no significant differences in SGR,WGR,PER and FCR in B2 and B4,compared with the control group (P>0.05).(2) There were no significant difference in moisture,ether extract,and ash contents among all groups (P>0.05);compared with the control group,crude protein of B2 was significantly decreased (P<0.05),but no significant difference was found in groups B0 and B4 (P>0.05);crude protein content of B4 was significantly higher than that of B0 and B2 (P<0.05).(3) There was no significant difference in trypsin activity among all groups (P>0.05);the amylase activity of B0 was significantly increased,compared with control group and B4 (P<0.05);there was no significant difference in amylase activity in B4 group compared with control group (P>0.05);the lipase activity of B4 was significantly increased control group (P<0.05).(4) The contents of essential amino acids,non-essential amino acids,total amino acids and essential amino acid index in muscle hed no difference among all groups (P>0.05).The results suggested that crystal Met and coated Met in diets could promote the growth of carp.Based on the analysis of growth performance,digestive enzyme activity and amino acids content in muscle,0.2%coated Met could achieve the effect of 0.4%crystal Met.