【作者】 许毅；

【导师】 任继周； 王恬； 周岩民；

【作者基本信息】 南京农业大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 本研究采用动物体内外试验相结合的研究方法，体外试验测定豆粕中的果胶含量，进行体外酶解试验；选用肉仔鸡作为试验动物，对果胶酶不同添加水平对玉米豆粕日粮中养分利用率的影响进行动物体内评定。 体外试验测定了豆粕中果胶及半乳糖醛酸的含量；根据两种酶活单位定义标定了果胶酶的酶活；比较了两种酶活单位定义条件下，不同果胶酶水平对豆粕干物质消化率、还原糖释放量及黏度的影响，确定了体外条件下单位豆粕所需的果胶酶水平，为玉米豆粕型日粮中果胶酶的添加量提供了参考依据。结果表明：豆粕中果胶的含量约为10.45％，半乳糖醛酸的含量约为7.64％；果胶酶在两种酶活单位定义条件下酶活分别为12781.25U和1234.38U，果胶酶在动物消化道内环境条件下(pH 2.6-6.4，40℃)能保持约80％的活力；果胶酶能提高豆粕的干物质消化率和还原糖的释放量，但对黏度无明显的影响；在pH4.2，40℃条件下对豆粕进行酶解，果胶酶的最适添加量为4.6-6.2U/g豆粕。 动物试验选用840羽0日龄的从肉仔鸡，随机分为7组，每组5个重复，每个重复24只，考察果胶酶添加水平对肉鸡生产性能和消化机能的影响。试验组1、2、3、4、5、6组前期果胶酶添加水平分别为0.001％，0.005％，0.025％，0.125％，0.2％，0.275％，后期添加量为0.0008％，0.004％，0.02％，0.1％，0.16％，0.22％。结果表明：(1)添加果胶酶有改善肉鸡生产性能的趋势，全期日增重和料重比均有不同程度的改善。其中显著提高了前期生产性能(p＜0.05)，而后期不显著。生产性能的提高并不随果胶酶的添加水平线性增加，就全期而言添加0.025％果胶酶组生产性能最佳。(2)果胶酶显著提高了干物质、粗纤维和粗蛋白的消化率(p＜0.05)，对能量、粗灰份利用率有改善的趋势，对粗脂肪的利用率无明显影响，对钙、磷利用率的影响有待进一步研究。(3)果胶酶的水平除对空肠淀粉酶的无显著影响外，十二指肠淀粉酶、总蛋白水解酶，空肠总蛋白水解酶均呈先显著提高(p＜0.05)，然后降低的趋势。(4)果胶酶显著降低了十二指肠和空肠食糜的黏度(p＜0.05)，而对回肠食糜的黏度无显著影响。更多还原

【Abstract】 Using both vitro digestion methods and intro methods to study the effect of pectinase on the nutrition utilization of corn-soybean meal diet in broilers.In vitro digestion trial, the content of pectin and galacturonic acid in soybean meal was measured; the activity of pectinase was measured according to two kinds of pectinase unit definition; under these two kinds of pectinase unit definition ,the effect of different pectinase level on the dry matter digestion rate, the content of reducing sugar and viscosity of the soybean meal was studied in order to ascertain the optimize dose of pectinase (U/g soybean meal) in vitro digestion methods. The result showed: the pectin content of soybean meal was 10.45%, and the galacturoninc acid content was 7.64%; the activity of pectinase was 12781.25U/g and 1234.3 8U/g respectively according two kinds of pectinase unit definitionjthe pectinase can improve the dry matter digestion rate and the content of reducing sugar of the soybean meal, but it had no effect on the viscosity; under the condition of pH 4.2 and 40 C,the optimize dose of pectinase was 4.6-6.2U/g(soybean meal).840 AA broilers were randomly allocated to 7 dietary groups and replicated 5 times, which had 24 broilers, to study the effect of pectinase levels on the broilers performance and digestion function. Treatments’ diets of 0-21 days supplemented with pectinase at 0.001%, 0.005%, 0.025%, 0.125%, 0.2%, 0.275%, and 21-42 days treatments’s diets with 0.0008%, 0.004%, 0.02%, 0.02%, 0.1%, 0.016%, 0.022%. The results showed: (1) Supplementd with pectinase improved the broiler performance of 0~21days (p<0.05) and inclined to improve the broiler performance of 21-42 days(p>0.05). Supplemented with 0.025% pectinase in the diets of 0-21 days is the optimize dose, as well as the 0.02% pectinase in 21-42 days diets. (2) Supplemented with pectinase significant increased the digestibility of dry matter, crude protein and crude fibre(p<0.05), inclined to improve the energy metabolizable rate and digestibility of the crude ash(p>0.05), didn’t affect the digestibility of the crude fat. The effect of pectinase on the Ca and P are irregular with the pectinase levels and need further research. (3)The pectinase levels did’t affect the jejunum amylase, but the duodenum amylase, proteolytic enzyme and jejunum proteolytic enzymeinclined to significantly improve first (p<0.05), then the increasing extent decreased.(4)The pectinase significant decrease the chyme viscosity of duodenum and jejunum(p<0.05) but had no effect on the chyme viscosity of ileum(p>.05).更多还原