【作者】 王永花；

【导师】 周光宏； 高峰；

【作者基本信息】 南京农业大学 ， 动物营养与饲料科学， 2006， 硕士

【摘要】 为提高麦类饲料的营养价值，增加麦类作物在饲料中的应用，本文通过研究在小麦基础日粮中添加木聚糖酶制剂对肉仔鸡生长性能和内源酶活性等的影响，对木聚糖酶制剂在鸡胃肠道的作用模式进行了初步探讨。 对内仔鸡生长性能的影响 小麦基础日粮中添加木聚糖酶制剂，提高了肉仔鸡增重和饲料转换率。较小麦对照组，添加0.02％酶Ⅰ、0.05％酶Ⅰ、0.02％酶Ⅱ和0.05％酶Ⅱ组肉仔鸡增重分别提高2.22％，2.72％，4.19％和0.26％，差异不显著(P＞0.05)；料重比分别降低4.92％，5.46％，5.46％和4.37％，差异均极显著(P＜0.01)。 对肠道环境影响 1) 加酶后，肉仔鸡腺胃、十二指肠、空肠、回肠、结肠、盲肠和胰腺的相对重量表现不同程度下降；2) 加酶后，肉仔鸡回肠食糜相对重量大都下降显著(P＜0.05)，空肠食糜相对重量有下降趋势；3) 加酶对肉仔鸡食糜pH值无显著影响。 木聚糖酶活性变化 小麦日粮中添加木聚糖酶制剂，21日龄肉仔鸡消化道各段木聚糖酶活性存在显著差别。其中空肠木聚糖酶活性最大，盲肠和十二指肠活性次之。各加酶组肉仔鸡消化道各段食糜木聚糖酶活性的变化趋势一致。但0.05％酶Ⅱ组空肠的木聚糖酶活性低于其他三组，且空肠、盲肠和十二指肠木聚糖酶活性间无显著差异，与其他加酶组存在一定差异，表明不同木聚糖酶产品和添加量在畜禽肠道效应不同。 对肠道食糜内源酶活性影响 加酶后，肉仔鸡十二指肠、空肠和回肠食糜的淀粉酶活性有所增加；空肠和回肠食糜胰蛋白酶活性有所增加；大部分加酶组十二指肠、空肠和回肠食糜脂肪酶活性有增加趋势，但差异均不显著(P＞0.05)。 对胰腺和肠道粘膜内源酶活性影响 1) 加酶后，肉仔鸡胰腺胰蛋白酶和淀粉酶活性均有所升高，而胰腺总蛋白酶和脂肪酶活性大都有所下降，但差异均不显著(P＞0.05)；2) 加酶，对肉仔鸡小肠粘膜麦芽糖酶、蔗糖酶以及腺胃粘膜胃蛋白酶活性(包括U／mg蛋白和U／g粘膜)均无显著影响(P＞0.05)。更多还原

【Abstract】 In order to improve the nutritional value of the viscous-grains to animals and increase their application in feed production, this work was designed to study the influence of xylanase supplementation to a wheat-based diet on productive performance and endogenous enzymes activities of broilers. And the action mode of xylanase in the gastro-intestinal tract (GIT) of broilers was preliminarily investigated in this article.Broiler performance: Body weight gain (BWG) and feed conversion rate (FCR) were improved with the supplementation of xylanase in the wheat-based diet. Supplementing Enzyme I (0.02%, 0.05%) and Enzyme II (0.02%, 0.05%) , respectively ,increased BWG by 2.22%, 2.72%, 4.19% and 0.26%, but not affected; and significantly depressed (P<0.01) the feed to weight gain rate by 4.92%, 5.46%, 5.46% and 4.37%.Growth of digestive organs: 1) In general, relative weight of proventriculus, duodenum, jejunum, ileum, colon, cecum and pancreas of broilers were decreased with enzyme supplementation. 2) Relative weight of intestinal chyme in the ileum were almost significantly decreased (P<0.05), relative weight of chyme in the jejunum were only decreased not significant with enzyme supplementation. 3) The pH value of GIT chyme was not affected with enzyme supplementation.Change pattern of xylanase activity in the GIT : Xylanase activity in different GIT segments differed significantiy when enzymes were supplemented. A high value of xylanase activity was observed in the jejunum, followed by cecum and duodenum content. The change patterns of xylanase activity in separate GIT segment showed a similar tendency with different enzyme supplementation. However, xylanase activity in the jejunum with the administration of 0.05% Enzyme II was lower when compared with other three enzyme treatments and no significance was observed on xylanase activity between更多还原