饲料碳水化合物对南方鲇(Silurus meridionalis Chen)幼鱼消化酶活性的影响

实验室循环水养殖系统中，27．5℃条件下，以对照组（添加0％碳水化合物）和处理组（添加12％碳水化合物）的人丁配合饲料喂养南方鲇（Silurus meridionalis Chert）幼鱼（38～42g），在喂养0，2，4周后分别测定实验鱼胃、肠、胰的淀粉酶和蛋白酶活性．结果显示：胃、肠、胰淀粉酶活性在对照组与处理组之间差异均不显著；南方鲇幼鱼的淀粉酶活性的基础水平（未经实验处理的0周）在胃、肠分别为0．073，0．108U／mg，高于某些肉食性鱼类的相应水平；蛋白酶活性在摄人碳水化合物后却产生了明显的变化（卢〈0．05）．研究表明：南方鲇幼鱼淀粉酶活性对饲料碳水化合物的变化具有相对保守性，而蛋白酶活性对碳水化合物的变化则表现出明显的反应．本研究提示，南方鲇幼鱼能够利用饲料碳水化合物可能与其淀粉酶活性的基础水平较高有关．

Effect of Dietary Carbohydrate on Digestive Enzyme Activities in Southern Catfish (Silurus meridionalis Chen)Juveniles

Amylase and protease activities in stomach, gut and pancreas of southern catfish juveniles fed diets containing starch content (0% ,12%) were measured at 2 and 4 weeks. The same index was also measured at 0 week. The results showed that there was no difference between control and treatment group in amylase activities of three tissues. The basic level (0. 073 U/mg for stomach and 0. 108 U/mg for gut) of amylase activities was higher than some other carnivorous fishes. However, dietary carbohydrate had a great effect on protease activities. It suggested that southern catfish can use dietary carbohydrate due to its high level of basic amylase activities.