复合植物提取物对奶牛瘤胃细菌菌群的影响

目的] 研究饲粮中添加蒲公英、益母草、金银花和连翘4种植物的乙醇提取物对泌乳期荷斯坦奶牛瘤胃细菌菌群的影响。方法] 采用完全随机试验设计,将24头泌乳期荷斯坦奶牛随机分为对照组和试验组,每组12头。对照组饲喂基础饲粮,试验组饲喂基础饲粮+0.3%/（头·d）复合植物提取物。试验期共75 d,预试期15 d,正试期60 d。于试验正式期第60天通过口腔采集奶牛瘤胃液,提取瘤胃液样品总DNA,利用16S rDNA序列分析技术研究饲粮中添加复合植物提取物对奶牛瘤胃细菌菌群的影响。结果] 对照组与试验组的瘤胃微生物在OTU水平上可相互分离。试验组奶牛瘤胃细菌的α多样性指数与对照组差异不显著（P>0.05）。添加复合植物提取物改变奶牛瘤胃中17个细菌菌门相对丰度,但试验组与对照组差异不显著（P>0.05）;在门水平上,2组的拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）在总菌群中占比最高;在属水平上,试验组瘤胃细菌相对丰度与对照组差异不显著（P>0.05）,2组优势菌属均为普雷沃菌属1（Prevotella 1）。通过LEFse分析发现,与对照组相比,试验组奶牛瘤胃中的拟杆菌目（Bacteroidales）相对丰度显著（P<0.05）降低,而双歧杆菌科（Bifidobacteriaceae）的相对丰度显著（P<0.05）增加。结论] 在泌乳期奶牛饲粮中添加0.3%的蒲公英、益母草、金银花和连翘复合提取物具有调节瘤胃菌群的作用。

Effects of Compound Plant Extracts on Rumen Bacterial Flora in Dairy Cows

Objective] This study was conducted to assess the effects of dietary supplementation of compound ethanol extracts from Taraxacum mongolicum, Leonurus japonicus, Lonicera japonica and Forsythia suspensa on rumen bacterial flora in lactating Holstein dairy cows. Method] A total of 24 lactating Holstein dairy cows were randomly allocated to a control group （n=12） or an experimental group （n=12） by using a completely randomized experiment design. The control group fed a basal diet, and the experimental group fed the same basal diet supplemented with 0.3% compound plant extracts of DM per cow per day. The experiment lasted for 75 days, including a 15-day pre-experiment and a 60-day formal experiment. On day 60 of the formal experiment, the rumen fluid samples were orally collected and the total DNA was extracted. The impacts of dietary supplementation of compound plant extracts on variation of rumen bacterial flora in dairy cows were evaluated by using 16S rDNA sequence analysis. Result] The rumen microorganisms in the experimental group and the control group could be separated from each other at the OTU level. The α diversity index of rumen bacteria in the experimental group was not significantly （P>0.05） different from that in the control group. Dietary supplementation of compound plant extracts altered the relative abundance of 17 bacterial phyla in rumen in dairy cows to a certain extent, but no significant （P>0.05） differences were observed. At phylum level, Bacteroidetes and Firmicutes accounted for the highest proportions in total rumen bacteria. At genus level, the relative abundance of rumen bacteria in the experimental group was not significantly （P>0.05） different from that in the control group, and the dominant bacteria were Prevotella 1 in both of the groups. Linear discriminant analysis effect size （LEfSe） demonstrated that compared with the control group, the relative abundance of Bacteroidales in the experimental group was significantly （P<0.05） reduced, and that of Bifidobacteriaceae was significantly （P<0.05） elevated. Conclusion] Dietary supplementation of 0.3% compound extracts from Taraxacum mongolicum, Leonurus japonicus, Lonicera japonica and Forsythia suspensa has regulatory effects on rumen bacterial flora in lactating Holstein dairy cows.