【作者】 丁轲；

【导师】 倪学勤； 潘康成；

【作者基本信息】 四川农业大学 ， 预防兽医学， 2003， 硕士

【摘要】 本研究从鸡肠道中筛选了3株益生乳酸杆菌，其中D₁₁为德氏乳杆菌德氏亚种，D₂₂为发酵乳杆菌，G₅₂为食品乳杆菌。它们均能耐受pH2.0的酸度和0.6％的胆盐，对致病性大肠杆菌和沙门氏苗有较强的抑制活性，并检验得出乳酸杆菌的体外抑菌活性主要是通过代谢产物中的酸性或酸依赖性的热稳定性物质起作用。 用分光光度法对37种中草药进行了筛选，发现有20种在0.025-0.1％浓度范围内对乳酸杆菌有促进作用，其中陈皮、山萸肉、贯众、党参、栀子、刺五加、葛根对大肠杆菌有抑制作用；白术、陈皮、山萸肉、贯众、刺五加、葛根对沙门氏菌有抑制作用，从而可以确定这几种中草药具有益生元的功能。并根据中草药组方的原则，配制了两个方剂，方一为：黄芪、葛根、刺五加、栀子、麦芽、甘草；方二为2：党参、白术、陈皮、山萸肉、贯众、炙甘草。经验证它们也均具有益生元的功能。 合生元可以改善雏鸡的生产性能。两合生元在0-3周较对照组极显著提高周增重和日增重（P＜0.01），但这两合生元组只有第2周较乳酸杆菌组和中草药组差异显著或极显著，而两合生元组的料肉比在0-5周均较对照组和其余试验组极明显降低（P＜0.01），但各周与乳酸杆菌组无显著差异（P＞0.05），所以从综合效益考虑，合生元在0-3周添加效果最理想。 合生元可提高AA肉鸡的免疫功能。两合生元组在15日龄和35日龄时均可较对照组显著（P＜0.05）或极显著（P＜0.01）提高胸腺指数、法氏囊指数和脾脏指数；两合生元对新城疫效价的影响最明显，较对照组、乳酸杆菌组和两中草药组差异均极显著（P＜0.01）；两合生元组血清中的IgG较对照组、乳酸杆菌组和中草药组无明显差异（P＞0.05）；但IgA均较其余各组极显著提高（P＜0.01）。 合生元可使肠道中的菌群发生变化，15日龄时两合生元组中双歧杆菌数较对照组极显著提高（P＜0.01），乳酸杆菌和大肠杆菌数均较其余各组差异极显著（P＜0.01）；35日龄时，合生元2组的乳酸杆菌较中草药2组明显提高（P＜0.05）；各试验组中的大肠杆菌数都较对照组极显著降低（P＜0.01），两合生元组较乳酸杆菌组和中草药组明显降低（P＜0.05或P＜0.01）。 合生元可提高肠道中的蛋白酶和淀粉酶酶活。两合生元组的蛋白酶和淀粉酶均较对照组和两中草药组差异极显著（P＜0.01），与乳酸杆菌组无明显变化（P＞0.05）。更多还原

【Abstract】 Three beneficial Lactobacillii (D11, D22, G52) were isolated from ileum of adult chicken, they were preliminarily identified Ldelbrueckii, L.fermentum and L.alimentarius respectively. The results showed that they could tolerate low pH and high concentration bile-salt, above all there were powerful inhibition activity to pathogenic E.coli and Salmonella in vitro.20 kinds of Chinese herbal medicines (CHM) were screened, it proved to promote the growth of Lactobacilli by spectrophotography, but the growth of E.coli could be inhibited by tangerine peel, common macrocarpium, hydroxyl-farreol, tangshen, cape jasmine fruit, manyprickle acanthopanax root, schizonepeta; Salmonella could be inhibited by largehead atractylodes rhizome, tangerine peel, common macrocarpium, hydroxyl-farrad, manyprickle acanthopanax root, schizonepeta. According to the prescription principle of CHM, two prescriptions were designed, one was astragalus root, schizonepeta, baikal skullcap root, capejasmine fruit, germinated barley, liquorice; the other was tangshen, white atractylades rhizome, tangerine peel, common macrocarpium, hydroxyl-farred, liquorice, which were also proved as prebiotcs.Two sybiotics were composed of each of the two prescriptions and Lactobacilli, the experiment was designed to investigate the effect of different additives(Lactobacilli, CHM and sybiotics) on growth perfomence, immune function, gastrointestinal microbial population and enzyme activity of AA chickens. The results showed that growth performance of young AA chicken could be improved, and the feed consumed/gain of the two sybiotics groups dropped significantly, it was most reasonable to add sybiotics during 0-3 weeks on account of the whole economic benefit, immune funcation could be increased, their thymus index, bursa of fabricius index and spleen index, antibody titers to New Castle Disease Virus (NDV) and the concentration of IgA in serum could be increased. The microflora of ileum could be changed, thenumber of beneficial Bifidobecteria and Lactobacillus increased, but that of E. coll markedlydropped. The proteinase and a-amylase activity in intestine also could be increased.更多还原