多糖、寡糖、蛋白酶对凡纳滨对虾生长、消化酶活性及血清非特异性免疫的影响

Effects of polysaccharides,oligosaccharides and protease on growth,digestive enzyme activities and serum nonspecific immunity of white shrimp(Litopenaeus vannamei)

在基础饲料(对照组)中分别添加0.2%β-葡聚糖、0.05%黄芪多糖、0.4%甘露寡糖、175 mg/kg蛋白酶PT,饲喂初始体重为(4.55±0.08)g的凡纳滨对虾(Litopnnaus vannamei)6周,考察对凡纳滨对虾生长性能、血清非特异性免疫及消化酶活性的影响。结果表明:与对照组相比,饲料中添加0.2%β-葡聚糖、0.4%甘露寡糖及175 mg/kg蛋白酶PT可分别提高凡纳滨对虾增重率16.19%、12.78%、11.25%(P<0.05),降低饲料系数0.10、0.09、0.09(P<0.05);各处理组在肌肉水分、灰分、粗脂肪和粗蛋白含量上无显著差异(P>0.05);在血清非特异性免疫方面,各多糖、寡糖和蛋白酶添加组均显著提高血清酚氧化酶活力(P<0.05),添加0.4%甘露寡糖可提高溶菌酶、碱性磷酸酶活力(P<0.05),添加0.2%β-葡聚糖、0.4%甘露寡糖可显著提高超氧化物歧化酶活力(P<0.05);在消化酶活性方面,添加175 mg/kg蛋白酶PT可显著提高肝胰脏蛋白酶、脂肪酶和肠蛋白酶活性(P<0.05),添加0.2%β-葡聚糖及0.4%甘露寡糖可显著提高胃蛋白酶和肝胰脏脂肪酶活性(P<0.05)。上述结果表明,饲料中添加0.2%β-葡聚糖、0.4%甘露寡糖、175 mg/kg蛋白酶PT可提高凡纳滨对虾生长性能、改善消化酶活性,葡聚糖和甘露寡糖还具有改善血清非特异性免疫的功能,而添加0.05%黄芪多糖对凡纳滨对虾增重率、血清非特异性免疫无显著影响。

A 6-week feeding trial was conducted to study the effects of supplementation of polysaccharides,oligosaccharides and protease in diets on growth performance,serum nonspecific immunity and digestive enzyme activities of white shrimp（Litopenaeus vannamei）.Graded levels of 0.0%（control group）,0.2% β-glucan,0.05% astragalus polysaccharides,0.4% mannan oligosaccharides and 175 mg/kg protease PT were supplemented to diet.Each diet was randomly fed to four cages of white shrimp with initial average weight（4.55±0.08） g in 20 cages（2.5 m×1.2 m×1 m）for 6 weeks.Compared with control group,weight gain rates（WGR） of shrimp fed with 0.2% β-glucan,0.4% mannan oligosaccharides and 175 mg/kg protease PT were increased by 16.19%,12.78%,11.25%（P0.05）,and feed conversion rate（FCR） decreased by 0.10,0.09,0.09（P0.05）.There were no significant differences in contents of muscle moisture,ash,crude fat and crude protein among treatments（P0.05）.In respect of serum nonspecific immunity,phenoloxidase were significantly increased by all additives groups compared with control group（P0.05）,but no difference was found in MDA among groups（P0.05）.Shrimp fed with diet adding 0.4% mannan oligosaccharides had a significantly higher lysozyme and alkaline phosphatase activity,meanwhile activities of superoxide dismutase of 0.2% β-glucan and 0.4% mannan oligosaccharides groups were enhanced compared with control group（P0.05）.In respect of digestive enzymes activities,hepatopancreas protease activities of 0.05% astragalus polysaccharides and 175 mg/kg protease PT groups,intestine protease activity of 175 mg/kg protease PT group,stomach protease activity of 0.2% β-glucan and 0.4% mannan oligosaccharides groups,hepatopancreas lipase activity of 0.2% β-glucan,0.4% mannan oligosaccharides and 175 mg/kg protease PT were all significantly higher than those of control group（P0.05）.Results above showed that the addition of 0.2% β-glucan and 0.4% mannan oligosaccharides in diet could improve the growth performance,serum nonspecific immunity and digestive enzyme activities;addition of 175 kg/kg protease PT could improve the weight gain rate and digestive enzyme activites;addition of 0.05% astragalus polysaccharides had no influence on weight growth rate,serum nonspecific immunity and digestive enzyme activities.