1～35日龄羔羊小肠消化酶活性的研究

Study on Development of the Small-intestinal Digestive Enzyme Activity of 1-35 days' Small-tail Han Sheep Lambs

选取初生体重（3.38±0.33）kg的小尾寒羊公羊56只,分为2组,从4日龄起分别饲喂牛奶粉代乳料或鱼粉代乳料,并在21日龄将原饲喂牛奶粉代乳料和鱼粉代乳料的羔羊各8只转喂开食料,在7、14、21、28和35日龄各屠宰4只,取小肠各段食糜,测定小肠食糜上清液的α-淀粉酶、乳糖酶、胰蛋白酶和糜蛋白酶的酶活性及体增重,以研究不同日龄和不同代乳条件下羔羊小肠消化酶的发育。结果表明,饲喂牛奶粉代乳料时羔羊小肠α-淀粉酶、乳糖酶、胰蛋白酶和糜蛋白酶活性随日龄变化,饲喂牛奶粉代乳料时羔羊日增重平均为157.2g/（只·d）,随日龄变化不显著;饲喂鱼粉代乳料时羔羊小肠的α-淀粉酶、乳糖酶、胰蛋白酶和糜蛋白酶活性在不同日龄均低于饲喂牛奶粉代乳料羔羊,平均分别低43.7%、46.0%、35.2%和10.2%,饲喂鱼粉代乳料时羔羊日增重降低,特别是在21日龄后,提示可能受鱼粉蛋白免疫反应的影响。在21日龄给羔羊转喂开食料,羔羊小肠的α-淀粉酶、乳糖酶、胰蛋白酶和糜蛋白酶活性降低,但之后逐渐恢复,在21日龄前饲喂牛奶粉代乳料的羔羊转喂开食料时α-淀粉酶、乳糖酶和胰蛋白酶活性降低的程度较饲喂鱼粉代乳料的大,但活性仍较高。由本研究得出结论,1~35日龄羔羊小肠α-淀粉酶、胰蛋白酶和糜蛋白酶活性随日龄增加,乳糖酶活性随日龄降低;羔羊饲喂鱼粉代乳料时小肠消化酶活性显著降低;在21日龄转喂开食料后,羔羊出现消化障碍,但较短期内可恢复。

56Small-tail Han sheep lambs with birth body weight（3.38±0.33）kg were randomly divided into two groups（n=28each group）,fed with milk powder substitute or fish meal substitute since 4days of age respectively and after 21 days of age,eight lambs in each group were turned to starting feed.At the age of 7,14,21,28 and 35days,four lambs were slaughtered from each group respectively.The contents of small intestine were collected,determining theα-amylase activity,lactase activity,trypsinase activity,chymotrypsin activity of chyme supernatant from the small intestine,to investigate the enzyme activity in small intestine at different ages with different milk substitutes.The results showed that the activity ofα-amylase,lactase,trypsinase,chymotrypsin of chyme supernatant from small intestine of the lamb fed with milk powder substitute was linearly correlated with age,and the average daily gain was 157.2g/d,without significant change with age.At different ages,the activity ofα-amylase,lactase,trypsinase,chymotrypsin of chyme supernatant from small intestine of the lambs fed with fish meal substitute was inferior to those fed with milk powder substitute,43.7%,46.0%,35.2%and 10.2% on average,respective-ly,and the average daily gain was reduced,especially after 21 days of age.It was revealed that the growth of the lamb fed with fish meal substitute might be influenced by the immune response of fish meal protein.After the lambs were given starting feed,the activity ofα-amylase,lactase,trypsinase,chymotrypsin of chyme supernatant from small intestine decreased,but recovered later.The activity ofα-amylase,lactase,trypsinase of the lamb fed with milk powder substitute before 21 days of age reduced more than the lambs fed with fish meal substitute,but the activity was still high.It was concluded that the activity ofα-amylase,trypsinase,chymotrypsin of chyme supernatant from small intestine of the lamb increased with age,the activity of lactase decreased with age,while the activity of digestive enzyme in the small intestine of the lamb fed with fish meal substitute was significantly reduced.After the lambs were fed with starter,digestive obstacle occurred,but disappeared later.