低鱼粉饲料中添加微胶囊或晶体蛋氨酸对凡纳滨对虾消化酶活性的影响

在低鱼粉饲料中分别添加晶体蛋氨酸(MET)、羟基蛋氨酸(MHA)和3种微胶囊蛋氨酸邻苯二甲酸醋酸纤维素包被蛋氨酸(CAP)、棕榈酸甘油酯包被蛋氨酸(TPA)、树脂包被蛋氨酸(RES),配制5种等氮等能饲料,以晶体蛋氨酸为对照组进行50 d的凡纳滨对虾(初重(0.81±0.01)g)养殖试验,测定对虾消化酶活力的变化。分别在养殖14、28、50 d时,取肝胰腺测定消化酶活性。结果表明,TPA组在养殖14、28、50 d时总蛋白酶活性呈现升高的趋势,50 d时TPA组显著高于RES组(P<0.05);50 d时,MET组脂肪酶活力显著高于其他处理组(P<0.05),淀粉酶活力低于微胶囊组但未见显著差异(P>0.05)。表明低鱼粉饲料中添加TPA微胶囊蛋氨酸有助于提高凡纳滨对虾蛋白酶和淀粉酶的活性。

Effects of Microcapsules or Crystalline Methionine in Lower Fishmeal Diets on Digestive Enzyme Activity of Pacific White Shrimp(Litopenaeus vannamei)

To evaluate the effects of microcapsules or crystalline methionine in diets of Pacific white shrimp(Litopenaeus vannamei)on digestive enzyme activities in hepatopancreas at day 14,28 and 50,five iso-nitrogen and iso-energy diets were prepared in which three diets were supplemented with cellulose-acetate-phthalate(CAP),tripalmitin-polyvinyl alcohol(TPA)and resin(RES)coated L-methionine,respectively.Hydroxyl-methionine calcium(MHA) was supplemented as the fourth diet and crystalline L-methionine diet(MET) was used as the control.Five triplicate groups of shrimp((0.81±0.01)g in initial body weight) were fed each test diets for 50 days.The results showed that total protease activity of shrimp fed TPA was increased at day 50 compared with day 14 and 28,and that was significantly higher than RES(p<0.05).Shrimp fed MET had significantly higher lipase activity than the others(p<0.05) and lower amylase activity than microcapsule methionine groups without difference(P>0.05)at day 50.The results above showed that supplementation microcapsule methionine(TPA) in shrimp diets contributed to enhancing total protease and amylase activity.