【摘要】 【目的】旨在研究不同形式氧化锌对肉兔肠道形态、空肠黏膜紧密连接蛋白基因表达、肠道食糜消化酶活性和盲肠发酵的影响。【方法】选取162只35日龄断奶新西兰白兔，随机分为3组，每组27个重复，每个重复2只，分别饲喂在基础饲粮中添加锌水平为120 mg/kg的饲料级氧化锌（F-ZnO）、纳米氧化锌（N-ZnO）和包被氧化锌（C-ZnO）的饲粮。正试期42 d，分别于21 d和42 d每组选择6只试验兔（即每组6个重复，每个重复1只）屠宰取样，测定肠道和食糜相关指标。【结果】(1)与F-ZnO相比，饲粮添加N-ZnO和C-ZnO均显著提高肉兔十二指肠绒毛高度，降低隐窝深度，提高绒隐比（V/C）(P<0.05)。与F-ZnO和C-ZnO相比，N-ZnO显著提高21 d回肠绒毛高度，降低隐窝深度，提高V/C(P<0.05)；显著降低42 d空肠隐窝深度，提高V/C(P<0.05)。(2)与F-ZnO相比，饲粮添加N-ZnO和C-ZnO均可显著提高试验第21天肉兔空肠Claudin、ZO-1和ZO-2基因表达（P<0.05），显著提高试验第42天空肠Occludin基因表达（P<0.05）。(3)与F-ZnO相比，N-ZnO可显著提高试验第42 d盲肠食糜纤维素酶活性（P<0.05）。3组间空肠食糜脂肪酶、淀粉酶和胰蛋白酶活性，盲肠食糜半纤维素酶和果胶酶活性各组间无显著差异（P>0.05），盲肠食糜总挥发性脂肪酸及乙酸、丙酸和丁酸比例无显著差异（P>0.05）。【结论】肉兔饲粮添加N-ZnO和C-ZnO改善小肠形态结构，提高空肠黏膜紧密连接，促进了肉兔肠道健康，C-ZnO效果更优。更多还原

【Abstract】 【Objective】The present study was conducted to investigate the effects of different forms of zinc oxide on intestinal morphology, the expression of tight junction protein gene in jejunum mucosa,intestinal chymase activity and cecal fermentation in meat rabbits. 【Method】A total of 162 New Zealand white rabbits,weaned at an age of 35 d, were randomly divided into three groups, with 27 replicates in each group and 2 rabbits in each replicate. They were fed with a basal diet supplemented with feed grade zinc oxide(F-ZnO), nano zinc oxide(N-ZnO) and coated zinc oxide(C-ZnO) at a zinc level of 120 mg/kg in the basic diet. During the trial period of 42 days, 6 rabbits in each group were selected for slaughter sampling at 21 d and 42 d respectively. 【Result】(1) Compared with F-ZnO, dietary N-ZnO and CZnO significantly increased duodenal villus height, decreased crypt depth and increased villus/crypt ratio(V/C)(P<0.05). Compared with F-ZnO and C-ZnO, N-ZnO significantly increased the ileal villus height, decreased the crypt depth, and increased V/C at 21 days of test(P<0.05).And the depth of jejunal recess was significantly decreased and V/C was increased at 42 days of test(P<0.05).(2) Compared with F-ZnO, both the genes expression of Claudin, ZO-1 and ZO-2 at 21 d and that of Occludin at 42 d in the jejunum mucosa of meat rabbits in N-ZnO group and C-ZnO group were significantly up-regulated(P<0.05).(3) Compared with F-ZnO, N-ZnO significantly increased the cellulase activity of caecal chyme at 42 d(P<0.05). There was no significant difference in the activities of lipase, amylase and trypsin in jejunum chyme, hemicellulase and pectinase in cecal chyme in rabbits among the three groups(P>0.05), and N-ZnO and C-ZnO did not affect concentration of the total volatile fatty acids and the proportion of acetic acid, propionic acid and butyric acid in cecal chyme of rabbits(P>0.05). 【Conclusion】The addition of N-ZnO and C-ZnO can promote the morphological development of small intestine in meat rabbits, improve the tight connection of jejunum mucosa, and enhance the intestinal health of meat rabbits.更多还原