不同壁材微胶囊饲料对黄姑鱼稚鱼生长和消化酶活力的影响

EFFECTS OF DIFFERENT WALL MATERIALS OF THE MICROENCAPSULATED DIETS ON THE GROWTH AND DIGESTIVE ENZYME ACTIVITY OF NIBEA ALBIFLORA LARVAE

研究采用湿法制粒流化床包衣工艺,分别以明胶、乙基纤维素、玉米醇溶蛋白为壁材制备微胶囊饲料,比较其对黄姑鱼稚鱼生长和消化酶活力的影响。粒径(178—590)μm的3种微胶囊饲料质量均大于50%。扫描电镜观察微胶囊饲料的表面均有一层较为致密的包衣薄膜。壁材明胶、乙基纤维素、玉米醇溶蛋白微胶囊饲料的包含率分别为95.4%、95.6%和95.8%;脂类包埋率分别为72.6%、76.5%和64.3%;氮保留率分别为53.5%、62.3%和54.6%。将3种微胶囊饲料分别饲喂15日龄黄姑鱼稚鱼30d。明胶组和玉米醇溶蛋白组稚鱼的体重、全长均显著高于乙基纤维素组(P<0.05),但成活率差异不显著(P>0.05);明胶组稚鱼的体重、全长和成活率均高于玉米醇溶蛋白组,但差异均不显著(P>0.05)。明胶组稚鱼的胰蛋白酶活力显著高于乙基纤维素组和玉米醇溶蛋白组(P<0.05),但淀粉酶和碱性磷酸酶活力的差异均不显著(P>0.05)。与乙基纤维素、玉米醇溶蛋白相比,明胶更适合作为黄姑鱼稚鱼微胶囊饲料壁材。

In this study, we evaluated the effects of different wall materials of microencapsulated diets on the growth and the digestive enzyme activity of N. albiflora larvae. Three groups of diets were microencapsulated with gelatin, ethyl celluse, and zein. The microencapsulated diets were prepared with wet granulation and fluidized bed coating process. More than 50% of the microencapsulated diets had diameters between 250 μm and 590 μm. Scanning electron microscopy microphotographs showed that the surface of the microencapsulated diet was covered by a dense film. The inclusion efficiency of the gelatin, ethyl celluse, and zein groups was 95.4%, 95.6% and 95.8%, respectively; the lipid encapsulation efficiency was 72.6%, 76.5% and 64.3%, respectively; the nitrogen retention efficiency was 53.5%, 62.3% and 54.6%, respectively. A 30-day feeding experiment was conducted with the larvae at DAH 15. At DAH 20, the larvae were weaned from copepods to the experimental diets. The wet weight and total length of larvae from the gelatin group and the zein group were significantly larger than those from the ethyl cellulose group(P<0.05). There was no significant difference in the survival rate between the groups. The trypsin activity of the larvae from the gelatin group was significantly higher(P<0.05) than the ethyl cellulose group and the zein group. There were no significant differences in the amylases activity and the alkaline phosphatases activity between the groups. Therefore compared to ethyl cellulose and zein, gelatin should be more suitable for the wall material of the microencapsulated diets for N. albiflora larvae.