饲料蛋白水平对中华鳖稚鳖生长和消化酶活性的影响

Effects of dietary protein levels on growth performance and digestive enzyme activities of Chinese soft-shelled turtle Pelodiscus sinensis juvenile

配制蛋白水平分别为34%,37%,40%,43%和46%的五组等能饲料,饲养中华鳖日本品系稚鳖(3.70±0.05 g)8周,探讨饲料不同蛋白水平对稚鳖生长、饲料利用率以及消化酶活性的影响。试验结果表明,试验鳖的增重率、饲料利用效率随着饲料蛋白含量的增加而提高,在43%蛋白饲料组达到最佳值(P<0.05);当饲料蛋白含量增加到46%,试验鳖生长表现不再显著提高(P>0.05)。随着饲料蛋白水平的提高,试验鳖胃、肝脏和肠道的蛋白酶活性均呈现上升趋势,其中胃和肝脏蛋白酶活性均在43%蛋白饲料组达到最大值,肠道蛋白酶活性在46%蛋白饲料组最高。各组织中淀粉酶活性以及肝脏脂肪酶活性随饲料蛋白水平的提高显著下降(P<0.05),胃和肠道脂肪酶活性下降趋势不显著(P>0.05)。

An 8 weeks＇ feeding trial was conducted to evaluate the effects of dietary protein level on growth,feed utilization and digestive enzyme activities of juvenile Chinese soft-shelled turtle,Pelodiscus sinensis Japanese strain with the primary weight of（ 3. 70 ± 0. 05） g. Five iso-energetic diets were formulated to contain graded protein levels of34%,37%,40%,43% and 46%. The results showed that the growth performance of the soft-shelled turtles and feed utilization ratio were significantly increasing with the dietary protein level enhancing（ P〈0.05）,while no further growth increase was observed beyond 43% protein level（ P〈0.05）. The pepsin activity in stomach,and the protease in liver and intestinal tract increased significantly with increasing dietary protein levels. The highest values in stomach and liver were observed in 43% protein group,while for intestinal tract was in 46% protein group. The amylase activities in all detected organs and lipase activity in liver decreased significantly when dietary protein levels increased（ P〈0.05）,however,lipase activities in stomach and intestinal tract showed indistinctive decline trendamong the dietary treatments（ P〈0.05）.