Rumen Microbial Population Dynamics during Adaptation to a High-Grain Diet
Rumen Microbial Population Dynamics during Adaptation to a High-Grain Diet
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DOI：
10.1128/aem.00388-10
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发表时间：
2010-11-01
影响因子：
4.4
通讯作者：
DeSilva, U.
中科院分区：
文献类型：
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作者：
Fernando, S. C.;Purvis, H. T., II;DeSilva, U.
高谷物适应计划被广泛用于饲养场牛，以平衡增强的生长性能和酸中毒的风险。这种从高饲料饮食到高谷物饮食的适应性改变了瘤胃微生物种群结构，有助于在瘤胃内建立稳定的微生物种群。因此，为了评估适应高谷物饮食期间的细菌种群动态，使用含有谷物和干草的比例为20：80、40：60、60：40和80：20的递增饮食方案，使4头瘤胃插管肉牛适应高谷物饮食。瘤胃细菌种群进行了评估，在每个阶段的逐步增加的饮食后1周的适应，之前的阉牛过渡到下一阶段的饮食，使用末端限制性片段长度多态性（T-RFLP）分析，16 S rRNA基因文库，和定量实时PCR。T-RFLP分析显示，在最后两个阶段的逐步增加饮食的瘤胃微生物种群结构的转变。16 S rRNA基因文库显示了两个不同的瘤胃微生物种群在干草喂养和高谷物喂养的动物，并检测到只有24个共同的操作分类单位的398和315，分别。干草喂养的动物的16 S rRNA基因文库含有显著较高数量的属于纤维杆菌门的细菌，而谷物喂养的动物的16 S rRNA基因文库含有显著较高数量的属于拟杆菌门的细菌。实时PCR分析检测到埃氏巨球菌，牛链球菌，反刍月形单胞菌，和普雷沃氏菌种群在适应高浓缩（高谷物）饮食的显着倍数增加，而溶纤维丁酸弧菌和产琥珀酸纤维杆菌种群逐渐减少，因为动物适应高浓缩饮食。本研究使用几种分子方法评估瘤胃微生物种群，并提出了一个更广泛的图片瘤胃微生物种群结构在适应高谷物饲料饮食。
High-grain adaptation programs are widely used with feedlot cattle to balance enhanced growth performance against the risk of acidosis. This adaptation to a high-grain diet from a high-forage diet is known to change the rumen microbial population structure and help establish a stable microbial population within the rumen. Therefore, to evaluate bacterial population dynamics during adaptation to a high-grain diet, 4 ruminally cannulated beef steers were adapted to a high-grain diet using a step-up diet regimen containing grain and hay at ratios of 20:80, 40:60, 60:40, and 80:20. The rumen bacterial populations were evaluated at each stage of the step-up diet after 1 week of adaptation, before the steers were transitioned to the next stage of the diet, using terminal restriction fragment length polymorphism (T-RFLP) analysis, 16S rRNA gene libraries, and quantitative real-time PCR. The T-RFLP analysis displayed a shift in the rumen microbial population structure during the final two stages of the step-up diet. The 16S rRNA gene libraries demonstrated two distinct rumen microbial populations in hay-fed and high-grain-fed animals and detected only 24 common operational taxonomic units out of 398 and 315, respectively. The 16S rRNA gene libraries of hay-fed animals contained a significantly higher number of bacteria belonging to the phylum Fibrobacteres, whereas the 16S rRNA gene libraries of grain-fed animals contained a significantly higher number of bacteria belonging to the phylum Bacteroidetes. Real-time PCR analysis detected significant fold increases in the Megasphaera elsdenii, Streptococcus bovis, Selenomonas ruminantium, and Prevotella bryantii populations during adaptation to the high-concentrate (high-grain) diet, whereas the Butyrivibrio fibrisolvens and Fibrobacter succinogenes populations gradually decreased as the animals were adapted to the high-concentrate diet. This study evaluates the rumen microbial population using several molecular approaches and presents a broader picture of the rumen microbial population structure during adaptation to a high-grain diet from a forage diet.