甜高粱青贮有氧稳定性、瘤胃降解率及其对瘤胃菌群影响的研究

发布时间：2018-06-20 03:59

本文选题：甜高粱 + 青贮发酵　；参考：《塔里木大学》2017年硕士论文

【摘要】：甜高粱具有生物产量高、含糖量高、抗旱、耐贫瘠等优良特性,是一种极具开发潜力的青贮饲料作物。甜高粱青贮饲料在动物养殖方面的的研究已有少量报道,然而,有关甜高粱青贮的瘤胃降解特性、有氧稳定性,以及对瘤胃微生物影响的研究却少见报道。为此,本试验选用高糖、低糖甜高粱品种和普通玉米制作的三种青贮为实验材料,采用尼龙袋降解试验、变性凝胶电泳和高通量测序技术,以及在有氧暴露0、5、10、15、20和25d时干物质、水溶性碳水化合物(WSC)、pH、温度、和微生物数量的变化,对高糖(HSS)、低糖(LSS)甜高粱青贮和玉米青贮(MZS)的降解率、有氧稳定性,及其对瘤胃菌群的影响进行了比较研究,得出如下主要结果:(1)有氧稳定性的研究结果显示,在有氧暴露环境下,LSS有氧稳定性最好,酵母菌、霉菌和好氧细菌数量增加最少;HSS有氧稳定性最差,酵母菌、霉菌和好氧细菌数量增加最多;MZS有氧稳定性和好氧性微生物数量居中;(2)瘤胃降解试验表明,在瘤胃发酵降解的前期(24h),HSS的干物质(DM)、中洗纤维(NDF)降解率均显著高于MZS和LSS(P0.05),在24 h时,MZS和HSS的DM和NDF降解率达到了相似水平(P0.05)。HSS粗蛋白质(CP)的24 h和48 h降解率显著高于MZS和LSS(P0.05);(3)与LSS相比,饲喂HSS与MZS可以增加瘤胃微生物的数量和种类,饲喂HSS和MZS的瘤胃微生物相似性为80%,而LSS与HSS和MZS的瘤胃微生物相似性只有60%;(4)HSS和MZS的瘤胃细菌菌群结构具有很高相似性,二者与LSS瘤胃细菌存在明显差异。LSS瘤胃中厚壁菌门是优势菌群(占78.5%),而MZS和HSS瘤胃中的优势菌群是拟杆菌门和变形菌门;从科属水平看,普雷沃菌属和琥珀酸弧菌科在MZS和HSS瘤胃中是优势菌群,毛螺旋菌科是LSS瘤胃中的优势菌群。三种主要瘤胃纤维降解菌,产琥珀酸丝状杆菌在MZS和HSS瘤胃中占细菌的1.5%,在LSS瘤胃中未检测到;黄色瘤胃球菌在HSS瘤胃中占1.4%,在LSS和MZS中含量相似,约占细菌总量的0.25%。未检测到白色瘤胃球菌。本研究表明,HSS与MZS的瘤胃降解率相似,二者的瘤胃菌群多样性和优势菌群相似度较高,HSS使黄色瘤胃球菌和产琥珀酸丝状杆菌数量增加,提示HSS可以通过调控瘤胃微生物以提高其降解率。同时,HSS有氧稳定性较差,容易发生二次发酵,因此,需要采取相应措施以提高其有氧稳定性。
[Abstract]:Sweet sorghum is a kind of silage crop with high biological yield, high sugar content, drought resistance and poor tolerance. There have been few studies on sweet sorghum silage in animal culture. However, there are few reports on rumen degradation, aerobic stability and effects on rumen microorganisms of sweet sorghum silage. For this reason, three kinds of silage made of high sugar, low sugar sweet sorghum and common corn were used as experimental materials, nylon bag degradation test, denaturing gel electrophoresis and high throughput sequencing technology, and dry matter at aerobic exposure of 0 ~ 5 ~ 10 ~ 10 ~ 1520 and 25 d ~ (-1), respectively. The changes of pH, temperature and microorganism quantity of water-soluble carbohydrate (WSCC) were compared to study the degradation rate, aerobic stability and the effect on rumen flora of sweet sorghum silage and corn silage MZSs with high sugar and low sugar LSSs. The main results are as follows: (1) the results of the study on aerobic stability show that the aerobic stability of LSS is the best under aerobic exposure, and the increase in the number of yeast, mold and aerobic bacteria is the least, and the aerobic stability of HSS is the worst, and that of yeast, The results of rumen degradation test showed that the number of mycetes and aerobic bacteria increased the most and the number of aerobic microbes was in the middle of MZS aerobic stability. In the early stage of rumen fermentation, the degradation rate of dry matter (DMN) of HSS was significantly higher than that of MZS and LSSP 0.05%. At 24 h, the degradation rates of DM and NDF of MZS and HSS reached the same level as that of crude protein CPP0.05. HSS at 24 h and 48 h, respectively. It was higher than MZS and LSSP 0.05 (P < 0.05) and compared with LSS (P < 0.05). Feeding HSS and MZS could increase the number and species of rumen microbes. The similarity of rumen microbes between HSS and MZS was 80, while the similarity between LSS and HSS and MZS was only 60%. There was significant difference between them and LSS bacteria. The dominant flora of LSS was 78.5%, while the dominant flora of MZS and HSS was Bacteroides and Proteus, and from the level of family and genus, the dominant bacteria in MZS and HSS were Bacteroides and Proteus, and in the level of family and genus, the dominant bacteria in MZS and HSS were Bacteroides and Proteus. Prevovobacter and Vibrio succinidae are dominant in MZS and HSS rumen, and helicidae are dominant in LSS rumen. Among the three main rumen fibrinolytic bacteria, filamentous succinate bacteria accounted for 1.5% of MZS and HSS rumen bacteria, but not in LSS rumen, while rumen coccus xanthococcus accounted for 1.4% in HSS rumen, similar in LSS and MZS, accounting for 0.25% of total bacteria. No rumen coccus was detected. The results showed that the rumen degradation rates of HSS and MZS were similar. The diversity of rumen flora and the similarity of dominant microflora between HSS and MZS increased the number of Rumen coccus and filamentous succinate producing bacilli. These results suggest that HSS can improve the degradation rate by regulating rumen microbes. At the same time, the aerobic stability of HSS is poor, so it is easy to produce secondary fermentation, so it is necessary to take corresponding measures to improve the aerobic stability of HSS.
【学位授予单位】：塔里木大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S816.53

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