外源α-淀粉酶对21日龄肉鸡消化器官发育、肠道内源酶活性的影响

Influence of Exogenous Alpha-amylase Supplementation on Development of Digestive Organs and Intestinal Enzyme Activities of 21-day-old Broilers

选用1日龄AA肉鸡440羽,随机分成4组,每组5个重复,分别饲喂基础日粮(对照组)和在基础日粮中添加1 000 U/kg(250 mg/kg)、3 000 U/kg(750 mg/kg)9、000 U/kg(2 250 mg/kg)微生物α-淀粉酶的试验日粮,研究添加不同剂量外源α-淀粉酶对肉鸡消化器官发育和内源酶活性变化的影响。结果表明:添加淀粉酶能降低肉鸡21日龄肝脏、肌胃、前肠相对重量和前肠相对长度(P>0.05),并提高了肉鸡前肠内容物淀粉酶、总蛋白酶(P<0.05)和胰蛋白酶(P<0.05)活性,但未影响脂肪酶活性,高剂量(2 250 mg/kg)添加组的总蛋白酶(P<0.05)和淀粉酶活性呈下降趋势;肉鸡空肠黏膜DNA、RNA浓度及蔗糖酶、麦芽糖酶活性未受淀粉酶水平(250 mg/kg和750mg/kg)影响,但高剂量(2 250 mg/kg)降低了蔗糖酶和麦芽糖酶活性(P<0.05)。

Four hundred and forty 1-day-old AA broiler chickens were randomly allocated to four groups for 5 replicates, and fed a commercial starter diet and the same diets supplemented with 1 000 U/kg （250 mg/kg）, 3 000 U/kg （750 mg/kg）, 9 000 U/kg （2 250 mg/kg） of α-amylase preparation up to 21 day of age to study the effects of supplementary α-amylase of different levels on the development of digestive organs, intestinal enzyme activities. The results showed that relative weights of liver, gizzard, anterior intestine and relative length of anterior intestine tended to decrease （P〉0.05）. The increased activities of amylase, protease （P〈0. 05）, and trypsin （P〈 0.05） in anterior intestinal and high-dose-depression responses with the amylase supplementation of 2 250 mg/kg were observed. Lipase activity, however, was unaffected by amylase supplementation of all levels （P〉0. 05）. DNA, RNA concentration and the activities of maltase and sucrase within jejunal mucosa were not affected by supplementary amylase of 250 mg/kg and 750 mg/kg. High-dose-depression responses were also observed for the activities of maltase and sucrase （P〈 0.05）.