木聚糖酶对鲫鱼生长性能和小肠绒毛的影响

Effects of Xylanase on Growth Performance and Small Intestinal Villus of Carassius auratus

采用单因子浓度梯度法,在以小麦为主的基础饲料中分别添加0.05%、0.10%和0.15%的木聚糖酶,以基础饲料为对照组,每组设4个重复,饲喂鲫鱼74d,测定鲫鱼的生长性能,观察肠道形态。结果表明:(1)0.05%组鲫鱼的增重率比对照组提高24.2%(P<0.01),0.10%组和0.15%组的增重率比对照组提高17.0%和15.7%(P<0.05);投饲系数分别较对照组降低19.2%、14.4%、13.6%(P<0.05)(。2)0.05%、0.10%和0.15%组的干物质表观消化率分别比对照组提高13.19%、9.33%和8.93%(P<0.01);蛋白质表观消化率分别比对照组提高9.98%、9.19%和8.82%(P<0.01);总糖表观消化率分别比对照组提高29.88%、26.67%和24.94%(P<0.01);(3)饲料添加木聚糖酶能促进小肠绒毛的发育。其中0.05%、0.10%和0.15%组前肠绒毛的高度分别较对照组提高了54.07%、34.96%和18.07(%P<0.01);0.05%组前肠绒毛的宽度较对照组提高了23.46%(P<0.01)。0.05%和0.10%组中肠绒毛的高度分别较对照组提高了6.60%(P<0.01)和3.96%(P<0.05)。0.05%和0.10%组中肠绒毛的宽度分别较对照组提高了10.95%和9.49%(P<0.01)。扫描电镜观察鲫鱼肠绒毛的超微结构,0.05%组前肠绒毛发育最好,绒毛排列整齐,微绒毛簇状结构致密,且很少黏附食糜颗粒。

Carassius auratus were fed with wheat-based diet which supplemented with 0.05 % ,0.10 % and 0.15 % Xylanase respectively for 74 days. The growth rate, the apparent digestibility and the small intestinal villus of the fish were measured. The results showed that：（1） Compared with the control, the weight gain of the group fed with 0.05 % xylanase was raised 24.2 % （P〈0.01）. The weight gains of 0.10 % and 0.15 % xylanase groups were 17.0 % and 15.7 % higher than that of control（P〈0.05）. （2）Apparent digestibility on the dry matter of 0.05 %,0.10 % and 0.15 % xylanase groups were 13.19 %, 9.33 % and 8.93 % higher than that of control respectively （P〈0.01）. The protein apparent digestibility increased 9.98%, 9.19 % and 8.82 % （P〈0.01）. The total carbohydrate apparent digestibility increased 29.88 %, 26.67 % and 24.94 % respectively （P〈0.01）. （3） Xylanase could promote the development of small intestine villi of the fish. The villous heights of fore-guts of 0.05 %, 0.10 % and 0.15 % xylanase groups were 54.07 %, 34.96 % and 18.07 % higher than that of control （P〈0.01）. The villous width of fore-gut of 0.05 % xylanase group was 23.46 % more than that of control （P〈0.01）. The villous height of mid-gut of 0.05 % and 0.10% xylanase groups were 6.60 % （P〈0.01） and 3.96 % more than that of control （P〈0.05）. The villous width of mid-gut of 0.05 % and 0.10 % xylanase groups were 10.95 % and 9.49 % more than that of control （P〈0.01）. The intestinal villi ultrastructure of Carassius auratus was observed with scanning electron microscope. The for-gut villi of 0.05 % xylanase group arranged regularly and developed best, their microvillus had compact structure and less chyme granules.