【作者】 唐建中；

【导师】 戴求仲； 张石蕊；

【作者基本信息】 湖南农业大学 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 一、芽孢杆菌的体外抑菌活性及其耐药性的研究试验采用牛津杯法和微量肉汤稀释法,分别测定了枯草芽孢杆菌和地衣芽孢杆菌对大肠埃希菌C83917、大肠埃希菌C83901和鼠伤寒沙门氏菌三种肠道致病菌的体外抑菌活性及对六类常用抗生素的耐药情况,结果表明：这两种益生芽孢杆菌对这三种致病菌都有底、中度的抑菌作用；六类抗生素中,对金霉素、抗敌素、黄霉素、硫酸粘菌素、喹乙醇有较强的耐受性,吉它霉素、硫酸新霉素对这两种益生菌抑制作用较强,不宜配伍使用。二、温度和调质制粒对芽孢杆菌影响的研究试验采用高温加热和调质制粒两种方法,测定了枯草芽孢杆菌和地衣芽孢杆菌的耐热性能,结果表明：两种芽孢杆菌对高温和制粒均有较强的耐受性。经90℃处理10min后,枯草芽孢杆菌的死亡率为12%左右,地衣芽孢杆菌为6.4%；90℃调质制粒后,枯草芽孢杆菌和地衣芽孢杆菌的死亡率分别为15.4%和7.1%。三、芽孢杆菌对黄羽肉鸡生产性能影响及作用机理的研究选择7日龄健康快长黄羽肉鸡(公母各半)375羽,随机分为5个处理,每个处理3个重复,每个重复25只鸡,试验期为7-56日龄。对照组(Ⅰ)饲喂基础日粮,试验组(Ⅱ、Ⅲ、Ⅳ、Ⅴ)分别在基础日粮中添加150g／t、200g／t、250g／t、300g／t的芽孢杆菌。在肉鸡56日龄时,评价其生产性能,测定相关血清理化指标,免疫器官指数及盲肠菌群,并通过代谢试验测定各试验组的养分利用率。试验结果表明：试鸡全期(7-56d)平均日增重以试验V组最高,明显高于对照组(P<0.05),但各试验组之间差异不显著(P>0.05),全期料重比以试验V组最低,显著底于对照组、试验Ⅱ、Ⅲ组(P<0.05)；试验V组试鸡的屠宰率比对照组有显著提高(P<0.05),各试验组间差异不显著(P>0.05)；胸腺指数以试验V组最高,明显高于对照组(P<0.05),也高于试验Ⅱ、Ⅲ、Ⅳ组(P>0.05)；血清中胰岛素(Ins)含量以试验V组最高,显著高于对照组(P<0.05),也比试验Ⅱ、Ⅲ、Ⅳ组高(P>0.05)；与对照组相比,各试验组能够显著降低肉鸡肓肠中大肠杆菌、沙门氏菌及总需氧菌的数量(P<0.05),增加乳酸杆菌的数量(P<0.05)；各试验组明显提高了肉鸡日粮蛋白质(P<0.05)和干物质(P>0.05)表观消化率,并提高了肉鸡日粮代谢能的浓度(P>0.05)和某些氨基酸的表观消化率(P<0.05)。更多还原

【Abstract】 Experiment 1:Studies on the Antimicrobial Activities in Vitro and Drug Resistances of BacillusThe experiment was comducted to detect the antimicrobial activities in vitro of B. subtilis and B. licheniformis on E. coli C83917,E. coli C83901 and Salmonella typhimurium as well as their resistances to six kinds of antibiotics which commonly used in the feed.The methods of experiment adopted were Oxford Cup and broth-microdilution.The results showed that both useful bacillus possess a low- medium bacteriostasis on these three pathogenic bacteria; these two bacillus had a tolerance for Chlortetracycline, Polymyxin E, Flavomycin, Polymyxin B and Olaquindox to some extent, but sensitive to Kitasamycin and Neomycin Sulfate.Experiment 2:Studies on the Effects of Temperature and Pelleting on BacillusThe heating of high temperature and pelleting were adoped to determine the heat resistances of B. subtilis and B. Licheniformis,the results showed that both bacillus could endure high temperature and pelleting, the mortality of B. Subtilis was 12% and that of B. Licheniformis was 6.4% after being processed through 90℃for 10 min; the mortalitis of B. Subtilis and B. Licheniformis respectively were 15.4% and 7.1% after pelleting at 90℃.Experiment 3:Studis on the Effects of Bacillus on the Performance of Yellow Broiler and its Related Mechanism375 yellow chickens of 7days old were randomly divided into 5 groups, with three replications per group and each replication with 25 chickens, the trial period was 7-56 days old.The control group (Ⅰ)was provided with the basal diet,the test groups (Ⅱ、Ⅲ、Ⅳ、Ⅴ) was fed a basal diet which added 150 g/t、200 g/t、250 g/t and 300 g/t bacillus respectively. At day 56,six chickens per group were slaughted to collected samples for testing the performance, blood biochemical indexes, weight of immune organs and cecal microflora, the nutrient availability was tested as well through metabolic trial. The result of this study showed that the ADG of test group V was significantly higher than control group I (P<0.05), but there was not significant difference among the test groups(P>0.05); Feed conversion ratio of the whole trial period of test group V was significantly lower than control groupⅠ,test groupⅡand test groupⅢ(P<0.05); Thymus index of test group V was the highest,significantly higher than that of control groupⅠ(P<0.05);the content of Ins in serum of test group V was higher than control groupⅠ(P<0.05),and also higher than othe test groups (P>0.05);compared with control groupⅠ,each test group could significantly low the amount of E. Coli, Salmonella and Aerobes(P<0.05) in the cecum of the chicken; all test groups significantly improved the apparent digestibility of CP (P<0.05)and DM(P>0.05) of diet on chicken, and enhanced the concentration of AME(P>0.05) and availability of some amino acids of the diet(P<0.05).更多还原