【作者】 李学俭；

【导师】 边连全；

【作者基本信息】 沈阳农业大学 ， 食品科学， 2008， 博士

【摘要】 本研究选取断乳仔猪为研究对象,通过β-甘露聚糖酶对断奶仔猪生长、免疫、肠道微生态的影响,对其机理进行了探讨。为β-甘露聚糖酶的系统开发利用、在仔猪断乳阶段饲料中的应用及适宜添加剂量提供科学的理论依据。特进行如下五个试验:试验一,选用健康的28日龄杜×长×大三元杂交断奶仔猪72头,随机分为4个处理组,每个处理3个重复,每个重复6头仔猪。第1组即对照组、第2组、第3组、第4组在饲喂基础日粮的基础上分别添加β-甘露聚糖酶0、0.025%、0.05%、0.1%。研究不同水平的β-甘露聚糖酶对断乳仔猪生产性能、营养物质消化率以及消化道酶活和养殖经济效益的影响,以确定最宜添加量。试验结果表明断乳仔猪日粮中添加一定剂量的β-甘露聚糖酶:1.可以不同程度地提高断乳仔猪日增重、日采食量,降低料重比和腹泻率（P＜0.05）。2.可以降低饲料成本2-7%,提高经济效益。3.除了对日粮中钙、磷的消化率影响不显著外（P＞0.05）,可以显著提高其它营养成分的表观消化率（P＜0.05）,4.可以显著地提高肠道胰蛋白酶和淀粉酶活性（P＜0.05）,对肠道脂肪酶没有产生显著性影响。5.就生产性能的影响而言,β-甘露聚糖酶的最宜添加量为0.05%。试验二,在试验一选出最宜添加量的基础上,选取150头健康的28±2日龄杜×长×大三元杂交断奶仔猪,随机分为5组,每组3个重复,每个重复10头猪。组1为基础日粮组,组2和组3为0.05%β-甘露聚糖酶和抗生素合用组,分别降低日粮能值80kcal/kg和100kcal/kg,组4和组5分别在降低日粮能值80kcal/kg和100kcal/kg基础上仅添加0.05%β-甘露聚糖酶。以研究0.05%β-甘露聚糖酶在断乳仔猪玉米-豆粕型日粮中的有效能值。试验结果表明:1.0.05%β-甘露聚糖酶在断乳仔猪玉米-豆粕型日粮中可以代替饲料能值80-100kal/kg。2.β-甘露聚糖酶和抗生素联合使用有协同作用。试验三:试验一进行时,于仔猪断奶前、断奶后即试验期的第一周、第二周、第三周、第四周末采血测定仔猪猪瘟抗体、T淋巴细胞转化率和血清生化指标。研究β-甘露聚糖酶对断乳仔猪生化指标和免疫机能的影响。试验结果表明断乳仔猪日粮中添加适宜剂量的β-甘露聚糖酶:1.可以显著提高血清T₄和IGF-1水平（P＜0.05）,对血清T₃没有显著性影响,因此在一定程度上促进了仔猪的生长。2.可以显著提高血清SOD、GSH-PX和T-AOC酶活力,降低血清MDA产量（P＜0.05）,从而提高了机体的抗氧化能力。3.可以显著提高血清IgA、IgG水平和T-淋巴细胞转化率（P＜0.05）,对血清IgM影响不显著,从而在一定程度上提高了机体的细胞免疫机能。4.对血清GPT、GOT活性没有产生影响,显著降低血清LDH、CK酶活力（P＜0.05）,一定程度上缓和了仔猪的断乳应激。5.可以显著提高猪瘟抗体效价（P＜0.05）,从而一定程度上提高了机体的体液免疫机能。6.可以显著提高血清AKP活力和血糖浓度,显著提高血清总蛋白、白蛋白水平（P＜0.05）,从而促进了机体内蛋白的沉积。对血清尿素氮没有显著性影响。7.对血清脂类的影响不显著（P＞0.05）,但一定程度上能调节机体脂类的代谢,加快脂肪的消化吸收,降低体内胆固醇的沉积。试验四:试验一结束当天上午每重复随机选取1头健康仔猪屠宰,立即取出相应的肠段,研究β-甘露聚糖酶对断乳仔猪肠道菌群和肠道组织形态的影响。试验表明断乳仔猪日粮中添加一定剂量的β-甘露聚糖酶:1.可以提高肠道双歧杆菌和乳酸杆菌的数量,降低肠道大肠杆菌数量（P＞0.05）。2.可以显著降低十二指肠、空肠、回肠、盲肠的pH值（P＜0.05）。3.可以显著提高十二指肠和空肠的肠绒毛高度,降低隐窝深度（P＜0.05）;提高了回肠的肠绒毛高度,降低隐窝深度,但差异不显著。4.综合β-甘露聚糖酶对肠道菌群和肠道组织形态的影响,0.05%β-甘露聚糖酶的效果好于其它两个剂量。试验五:于试验一基础上进行,于试验的第14天,28天分别在早、中、晚收集每重复组新鲜粪便各50g混合均匀后,放置冰盒中,迅速运至实验室-20℃下保存以供DNA提取→菌群DNA的PCR扩增→DGGE分析。从分子生物学角度研究β-甘露聚糖酶对断乳仔猪肠道菌群多样性的影响。试验结果表明:断乳仔猪日粮中添加一定剂量的β-甘露聚糖酶。1.试验前期可以显著提高DGGE图谱中条带数目和多样性参数H’（P＜0.05）,试验后期可以提高DGGE图谱中条带数目和多样性参数H’,但差异不显著（P＞0.05）。2.β-甘露聚糖酶可以在一定程度上缓解断乳应激所引起的细菌种类和数量的减少。本研究结论是,断乳仔猪日粮中添加一定剂量的β-甘露聚糖酶均能不同程度地提高断奶仔猪的日增重、日采食量,降低料重比和腹泻率;其中0.05%β-甘露聚糖酶在提高生产性能方面最好;其生产性能的提高是通过影响肠道微生态环境和血液生理生化指标、机体免疫机能而实现的。更多还原

【Abstract】 Early-weaned piglets（28d age）are useed as animal model to determine the effect of beta mannanase on performance、immunity、intestinal microecology of weaned piglets and discuss mechanism;to provide a scientific basis for utilizing and Appropriate dosage in weaned piglets’diets.The first experiment:Seventy-two 28-d-old weaned Duroc×Landrace×Yorkshire piglets were divided into four groups with three replicates,each of which including 6 piglets,in a randomized block design（male:female=1:1）to study the effect of beta mannanase on the performance、digestability of nutrients、intestinal digestive enzymes activity、economic efficencies and determine the optimal level of beta mannanase on the early weaned piglets..the frist group（control group）、the second、third and fourth group were fed with corn-soybean meal basal diet adding beta mannanase in 0%、0.025%,0.05%and 0.1%level.The whole experimental period was 4 weeks.The main results:Adding the optimal level of beta mannanase in dietary of weaned piglets.1.Dietary beta mannanase can increase the average daily gain group and the average daily feed intake,decrease the feed-meat ratio and the diarrhea frequencies compared with control group in the different degree（p＜0.05）.2.The cost of diets may be reduced by 2-7%,promoting economical efficiencies.3.The dietary beta mannanase can increase digestability of nutrient except Ca,P（p＜0.05）.4.The dietary beta mannanase can increase remarkably intestinal Parenzyme and Amylase activities（p＜0.05）.but had no significant effect on Lypase.5.The experimental group3（0.05%beta mannanase）was optimum in the way of improving performance.The second experiment:On the basis of the first experiment’ optimum.150 28-d-old weaned DurocxLandrace×Yorkshire pigs were divided into five groups with one-way random design,each group including 3 replicates（10 pigs per replicates）to determine the effective energy of 0.05%beta mannanase in weaned pigs’ diet.The first group was the control group,fed with corn-soybean basal diet.The group2 and group3,combination 0.05%beta mannanase with antibiotics,were fed with the basal diet decreased 80kal/kg and 100kal/kg energy respectively.The group4 and The group5 were fed with the basal diet decreased 80kal/kg and 100kal/kg energy respectively,and alone 0.05%beta mannanase.The whole experimental period was 4 weeks.The experimental results showed that:1.0.05%beta mannanase can instead 80-100kal/kg energy in the corn-soybean meal diet of weaned piglets.2.Beta mannanase and antibiotics may promote each other.The third experiment:At the start、the first weekend、the second weekend、the third weekend and the fourth weekend of the first experiment,preparing serum for biochemical parameters、the SFD antibody and TLR to study the effect of beta mannanase on serum biochemical parameters and immunity,discuss mechanism of beta mannanase on performance of weaned piglets.The experiment showed:the optimal level of beta mannanase in dietary of weaned piglet’s diets.1.Beta mannanase can advance serum T₄ and IGF-1（p＜0.05）,had no significant effect on serum T₃.so beta mannanase can promote performance of weaned piglets to some extent.2.Beta mannanase can advance serum SOD、GSH-PX、T-AOC activities remarkably（P＜0.05）,decrease serum MDA,promoting antioxidant capacity.3.Beta mannanase can advance serum IgG、IgA and the SFD antibody of piglets（p＜0.05）,had no significant effect on serum IgM,promoting humoral immunity of weaned piglets to some extent.4.Beta mannanase have no impact on serum GPT and GOT,decrease serum LDH、CK activities（p＜0.05）,slowing weaning stress of piglets to some extent.5.Beta mannanase can advance serum TLR（p＜0.05）,promoting Cellular immune function of weaned piglets to some extent.6.Beta mannanase can advance serum AKP antivities、GLU、TP、ALB（p＜0.05）, promoting protein deposition of weaned piglets,and had no sifinificant effect on serum BUN.7.Beta mannanase had no sifinificant effect on serum lipids level.but beta mannanase can regulate Lipid metabolism,Speed up digestion and absorption of fat, reduce deposition of cholesterol in the different degree. The fourth experiment:12 piglets（1 pig each replicate randomly）were slaughtered at the end of first experiment,the corresponding intestines were removed to study the effect of beta mannanase on intestinal flora and intestinal Morphology.The experiment showed that:Adding the optimal level of beta mannanase in dietary of weaned piglets.1.Beta mannanase can increase the quatities of benefical flora,reduce the quatities of harmful flora in the different degree（p＞0.05）.2.Beta mannanase can decrease intestinal pH（p＜0.05）.3.Beta mannanase can increase remarkably Villous height of Duodenum、Jejunum,decrease crypt depth of Duodenum、Jejunum（p＜0.05）;had no significant effect on Villous height and crypt depth of Ileum（p＞0.05）.4.Considering effects of beta-mannanase on intestinal flora and Morphology of weaned piglets,0.05%beta mannanase is the best. The fifth experiment:Collecting 50g fresh faecel of each replicate randomly selected at the first experimental 14d and 28d and mixturing,storing at-20℃.and extracting total DNA→PCR→DGGE to study the effect of beta mannanase on diversity intestinal flora of weaned piglets.The experiment showed that:Adding the optimal level of beta mannanase in dietary of weaned piglets.1.Beta mannanase can increase remarkably DGGE bands and H’of weaned piglets faecal samples in earlier period（P＜0.05）,had no significant effects on DGGE bands and H’ in later period（P＞0.05）.2.Beta mannanase can slow reducing of intestinal microbial kinds and quatities caused by weaning press.In the conclusion,the different dosage of beta mannanase added in the feed of weaned piglets can improve ADG and AFI,decrease F/G and diarrhea in the different degree;0.05%beta mannanase group is the best in the way of improving performance of weaned piglets;Improving of the production performance was gained by effect of beta mannanase on intestinal microecology,blood physiological and biochemical index and immunity.更多还原