Effect of different forage-to-concentrate ratios on ruminal bacterial structure and real-time methane production in sheep
Effect of different forage-to-concentrate ratios on ruminal bacterial structure and real-time methane production in sheep
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DOI：
10.1371/journal.pone.0214777
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发表时间：
2019-05-22
期刊：
影响因子：
3.7
通讯作者：
Lou, Yujie
中科院分区：
文献类型：
--
作者：
Li, Runhang;Teng, Zhanwei;Lou, Yujie
反刍动物的甲烷排放已成为中国最大的人为甲烷排放源之一。瘤胃植物群的结构对甲烷的产生有显著的影响。为了建立一个更准确的甲烷产量预测模型，瘤胃植物群应该是最重要的参数之一。本研究的目的是探讨不同粗精比日粮条件下绵羊瘤胃植物群、营养水平和甲烷产量变化之间的关系，并筛选出差异显著的优势菌群。将9只瘤胃插管杂交绵羊分为3组，分别饲喂粗精比为50：50、70：30和90：10的3种日粮。试验采用3 × 3不完全拉丁方设计，分3个阶段进行，每个阶段15d。本研究采用实时荧光定量PCR、高通量测序和体外瘤胃发酵技术，在一个新的实时发酵系统中，对瘤胃液进行实时荧光定量PCR、高通量测序和体外瘤胃发酵。22属进行了筛选，其丰富的线性变化与饲料浓度比和甲烷生产。另外，在12小时的体外发酵过程中，瘤胃菌群结构的不同使发酵高峰出现的时间推迟了26 - 27分钟。纤维降解菌与这一现象呈正相关，而淀粉降解菌和蛋白质降解菌则呈负相关。这些结果将有助于宏观控制瘤胃微生物和更好地管理日粮，以改善反刍动物的营养。此外，我们的研究结果将有助于筛选与甲烷生产高度相关的细菌属。
Emission from ruminants has become one of the largest sources of anthropogenic methane emission in China. The structure of the rumen flora has a significant effect on methane production. To establish a more accurate prediction model for methane production, the rumen flora should be one of the most important parameters. The objective of the present study was to investigate the relationship among changes in rumen flora, nutrient levels, and methane production in sheep fed with the diets of different forage-to-concentration ratios, as well as to screen for significantly different dominant genera. Nine rumen-cannulated hybrid sheep were separated into three groups and fed three diets with forage-to-concentration ratios of 50:50, 70:30, and 90:10. Three proportions of the diets were fed according to a 3 x 3 incomplete Latin square, design during three periods of 15d each. The ruminal fluid was collected for real-time polymerase chain reaction (real-time PCR), high-throughput sequencing and in vitro rumen fermentation in a new real-time fermentation system wit. Twenty-two genera were screened, the abundance of which varied linearly with forage-to-concentration ratios and methane production. In addition, during the 12-hour in vitro fermentation, the appearance of peak concentration was delayed by 26-27min with the different structure of rumen bacteria. The fiber-degrading bacteria were positively correlated with this phenomenon, but starch-degrading and protein-degrading bacteria were negative correlated. These results would facilitate macro-control of rumen microorganisms and better management of diets for improved nutrition in ruminants. In addition, our findings would help in screening bacterial genera that are highly correlated with methane production.