| 缓释尿素对牦牛瘤胃细菌和真菌群落组成的影响 | |
| Alternative Title | Effect of slow-release urea on the composition of ruminal bacteria and fungi communities in yak |
| 闫小婷 | |
| Subtype | 硕士 |
| Thesis Advisor | 邱强 |
| 2019-03-25 | |
| Degree Grantor | 兰州大学 |
| Place of Conferral | 兰州 |
| Degree Name | 硕士 |
| Degree Discipline | 生态学 |
| Keyword | 缓释尿素 细菌 真菌 牦牛 |
| Abstract | 牦牛是一种生活在青藏高原的典型反刍家畜，在长期应对高寒、缺氧及牧草冷暖季供给不平衡的恶劣环境下，形成了高效的氮素利用率。牦牛瘤胃微生物的结构和功能不但与其它反刍家畜显著不同，而且在牦牛氮素的代谢与利用方面发挥重要作用。因此，研究牦牛瘤胃微生物与氮素代谢的关系有助于提高我们对牦牛高原适应机制的认识。缓释尿素（Slow-release urea, SRU）是一种能被瘤胃微生物降解为氨的非蛋白氮饲粮添加剂，研究牦牛瘤胃氮素代谢的良好模型，但是有关缓释尿素对牦牛瘤胃微生物结构与功能的影响机制仍不清楚。 本研究系统比较了不同浓度缓释尿素添加（10或20 g/kg SRU的基础日粮，分别命名LSRU组和HSRU组）对牦牛生长性能和瘤胃微生物群落结构的影响。结果显示，LSRU组牦牛的日增重和饲料利用率要高于HSRU组。对于细菌而言，Prevotella 1、 Rikenellaceae RC9 gut group和Christensenellaceae R-7 group是牦牛瘤胃的优势细菌属（分别占测定OTUs数目的38.7、8.73和2.51%），随着SRU的增加，Chlorobi 和 Rikenellaceae RC9 gut group属细菌的丰度显著降低（P <0.05）。对于真菌而言，覆膜孢酵母属 （Saccharomycopsis）、 念珠菌属 （Candida）和Pseudopithomyces 属是牦牛瘤胃的优势真菌属（分别占测定OTUs数目的22.44、5.26和3.32%） 随着SRU的增加，毕赤酵母属（Pichia）、 Geotrichum 和 Monographella 真菌的丰度显著降低（P <0.05）。瘤胃细菌功能分析表明，随着SRU的增加，D型-谷氨酰胺和D型-谷氨酸代谢功能明显增强（P <0.05）。 我们结果表明SRU影响了牦牛瘤胃微生物区系，鉴定出与尿素代谢相关的关键微生物和代谢通路，为理解尿素代谢、尿素在牦牛以及其它生活在青藏高原的反刍动物中的应用提供了新的见解。 |
| Other Abstract | Yak is typical ruminant animals living in the Qinghai-Tibetan Plateau. Yak has evolved a high nitrogen utilization rate in the harsh environment with cold, low oxygen and seasonal imbalance of biomass production after a long adaptation. Previous studies demonstrated that the rumen microbiota of yak not only significantly differs different from the other ruminants, but also played an important role in the metabolism and utilization of nitrogen. Therefore, examining the relationship between rumen microorganisms and nitrogen metabolism will improve our understanding of about the yak adaptation. Slow-release urea (SRU) is a non-protein nitrogen that can be hydrolyzed to ammonia by rumen microbiota. SRU can be a good model for studying rumen nitrogen metabolism of yak. However, the effect of slow-release urea on the composition and function of the rumen of yak remains unclear.We arranged two dietary treatments: a basal diet containing 10 or 20 g/kg diet of SRU (designated LSRU and HSRU, respectively) to investigate the effect of slow-release urea on the composition and function of the rumen microorganisms of yak. The results showed the average daily weight gain and feed efficiency for yaks fed the LSRU diet were better than for those fed the HSRU diet. The dominant bacterial genera were Prevotella 1, Rikenellaceae RC9 gut group, and Christensenellaceae R-7 group (accounting for 38.7, 8.73 and 2.51% of detected OTUs, respectively). Increasing SRU supply significantly decreased (P < 0.05) abundance of the phylum Chlorobi and genus Rikenellaceae RC9 gut group. The dominant fungal genera were Saccharomycopsis, Candida, and Pseudopithomyces (accounting for 22.44, 5.26 and 3.32% of detected OTUs, respectively). Increasing SRU supply significantly decreased (P < 0.05) abundance of Pichia, Geotrichum and Monographella genera. Furthermore, the predicted functions of D-glutamine and D-glutamate metabolism were significantly decreased (P < 0.05) with an increase in SRU.Our results suggest that SRU has influenced rumen microbiota of yaks, and identified key microorganisms and metabolic pathways associated with urea metabolism, which provides new insights in understanding the urea metabolism, and shed lights on the urea application of yaks and other ruminants lived at Qinghai-Tibetan Plateau. |
| Pages | 56 |
| URL | 查看原文 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | https://ir.lzu.edu.cn/handle/262010/342016 |
| Collection | 生命科学学院 |
| Affiliation | 生命科学学院 |
| First Author Affilication | School of Life Sciences |
| Recommended Citation GB/T 7714 | 闫小婷. 缓释尿素对牦牛瘤胃细菌和真菌群落组成的影响[D]. 兰州. 兰州大学,2019. |
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