Temporal Dynamics in Rumen Bacterial Community Composition of Finishing Steers during an Adaptation Period of Three Months

Abstract

The objective of this study was to explore whether collecting rumen samples of finishing steers at monthly intervals differed, and whether this difference or similarity varied with diets. For these purposes, 12 Chinese Holstein steers were equally divided into two groups. The dietary treatments were either standard energy and standard protein (C) or low energy and low protein (L). Rumen samples were obtained on day 30, day 60 and day 90 from both dietary treatments and were analyzed by using 16S rRNA gene sequencing. The results showed that monthly intervals had no effect on the richness and evenness of the rumen bacterial community in the two diets. However, taxonomic difference analysis (relative abundance >0.5%) revealed that the relative abundance of three phyla (Proteobacteria, Fibrobacteres and Cyanobacteria) and six genera (Rikenellaceae_RC9_gut_group, Ruminococcaceae_NK4A214_group, Fibrobacter, Eubacterium_coprostanoligenes_group, Ruminococcaceae_UCG-010 and Ruminobacter) were significantly different between monthly sampling intervals, and the difference was prominent between sampling in the first month and the subsequent two months. Moreover, the differences in abundances of phyla and genera between monthly sampling intervals were affected by diets. Analysis of similarity (ANOSIM) showed no significant differences between monthly sampling intervals in the C diet. However, ANOSIM results revealed that significant differences between the first month and second month and between the first month and third month were present in the L diet. These results indicated that temporal dynamics in rumen bacterial community composition did occur even after an adaptation period of three months. This study tracked the changes in rumen bacterial populations of finishing cattle after a shift in diet with the passage of time. This study may provide insight into bacterial adaptation time to dietary transition in finishing steers.

Digestive Ability, Physiological Characteristics, and Rumen Bacterial Community of Holstein Finishing Steers in Response to Three Nutrient Density Diets as Fattening Phases Advanced

“…The predominant microbiota was quite different in seasons and opposite variation trend of Bacteroidetes abundance was observed in summer and winter [10]. Previous report revealed that both Succinivibrionaceae_UCG-002 and Ruminobacter abundances in rumen were positively associated with ambient temperature [8]. Yadav et al [11] found that low ambient temperature reduced the mean retention time of ruminal contents, thus low digestibility of digesta may appear.…”

“…One hundred and twenty-six ruminal samples (42 samples from each fattening phase, with 4, 5, and 5 in H, C, and L diets, respectively) were extracted using a DNA Kit (OMEGA, Omega Bio-Tek, Norcross, GA, USA) as described by Qiu et al [8]. Purity and quality of genomic DNA were checked on 1% agarose gels and quantified using a spectrophotometer (NanoDrop 2000 Technologies Inc., Wilmington, DE, USA).…”

“…The primers and PCR reaction system used in the current study were according to our previous report [8]. Briefly, the V3 to V4 was selected as the target hypervariable region, which was amplified with the following primers: 338F (5 -ACTCCTACGGGAGGCAGCAG-3 ) and 806R • C for 10 min.…”

“…Jami et al [5] characterized the dynamic bacterial compositions at five representative stages from birth to adulthood and observed convergent bacterial community as age advanced. Additionally, our previous studies in finishing steers revealed monthly temporal dynamics in composition of rumen bacteria even fed the same diet [8] and time-dependent alterations of fecal bacterial community in fattening stage [9]. However, information about the responses of ruminal bacteria to fattening diets in various nutrient densities, fattening stage, and their possible interaction is limited.…”

Characterization of the Rumen Microbiota and Volatile Fatty Acid Profiles of Weaned Goat Kids under Shrub-Grassland Grazing and Indoor Feeding

“…Although there is a core microbial community in the rumen [6,7], a large number of studies have reported that the rumen microbiome can be changed drastically by many factors, such as age [8][9][10], dietary source [11,12], feeding system [13][14][15], host species [7] and even geography [7]. For example, Wang et al investigated the temporal dynamics of the rumen microbiome in goats, and observed that the relative abundance of Firmicutes did not vary with age [9].…”