Comparison Of Different Microbial Communities In The Rumen Of Dairy Cows By PCR-DGGE And Real-time PCR

In the present study, two trials were conducted to anlyse the microbial communities of different fractions and compare the microbial communities adherent to three kinds in the rumen of Holstein dairy cows. The main studies as follows:Comparison of microbial communities adherent to three kinds of feeds in dairy cows by PCR-DGGE:In order to get the information of microbes involved in coarse degradation, microbial communities adherent to alfalfa hay, corn silage and Chinese wild hay in the rumen of Holstein dairy cows were analyzed.Three healthy Chinese Holstein dairy cows with permanent rumen cannula and similar weight were selected, three kinds of feeds were put in nylon bags respectively, then incubated in the rumen for 24h, the microbial communities adherent to feeds were eluted with PBS method and compared by DGGE. Some different and same bands were selected and sequenced. Phylogenetic tree was built by Mega 4.1. DGGE profiles showed the number and intensity of bands from different samples were different; The identity between alfalfa hay and alfalfa was low but the identity between corn silage and Chinese wild hay was high; Simpson index of different samples were different significantly (P<0.05), Shannon-Wiener index was not different significantly (P>0.05); The phylogenetic tree derived from 16s rDNA sequence was found that the closest relatives belonged to Clostridium sp., Brevibacillus spp., Bartonella spp,Bacteroidetes spp. The results showed that the microbial communities adherent to three feeds were different.Analysis of microbial communities of different fractions in the rumen of Holstein dairy cows by DGGE and Real Time PCR:Using Denaturing gradient gel electrophoresis(DGGE) and Real-time PCR (RT-PCR) to analysis the microbe population in Liquid Fraction, Adherent Fraction and Associated Fraction from the rumen of Holstein dairy cows.Whole ruminal contents were sampled from four Holstein dairy cows and partitioned into three fractions, then they were analyzed by DGGE and RT-PCR including general bacteria and Fibrobacter succinogenes.DGGE profiles showed the number and intensity of bands from different fractions were different; Bands clusters showed that the identity between liquid fractions and solid fraction was low; For different fractions, Evenness index were different significantly (P<0.05), Shannon-Wiener index and Dominance index was not different significantly (P>0.05); RT-PCR revealed that the gene copies of general bacteria between adherent fraction and liquid fraction or associated fraction were significantly different(P<0.01); the gene copies of general bacteria between liquid fraction and associated fraction were not different(P>0.05); the numbers of Fibrobacter succinogenes gene copies between three fractions were all significantly different{P<0.01). The microbe population structure in three fractions from the rumen of Holstein dairy cows were different..