Influence of wet distillers grains diets on beef cattle fecal bacterial community structure

Abstract

BackgroundThe high demand for ethanol in the U.S. has generated large stocks of wet distillers grains (DG), a byproduct from the manufacture of ethanol from corn and sorghum grains. Little is known, however, about the potential influence of dietary DG on fecal microbial community structure. A better understanding of the microbial population in beef cattle feces could be an important monitoring tool to facilitate goals of improving nutrient management, increasing animal growth performance and decreasing odors and/or shedding of pathogens. Five diets consisting of a traditional diet fed to finishing beef cattle in the Southern High Plains of Texas-CON (steam-flaked corn control with 0% DG), and four concentrations of DG in the dietary dry matter; 10 C (10% corn-based DG), 5S (5% sorghum-based DG), 10S (10% sorghum DG), and 15S (15% sorghum DG) were fed to steers at the Texas Tech University Burnett Animal Center. Diets were essentially isonitrogenous with a formulated crude protein value of 13.5%.ResultsFecal grab samples were obtained from 20 steers (n = 4 per diet) and the barcoded DNA pyrosequencing method was used to generate 127,530 16S operational taxonomic units (OTUs). A total of 24 phyla were observed, distributed amongst all beef cattle on all diets, revealing considerable animal to animal variation, however only six phyla (core set) were observed in all animals regardless of dietary treatment. The average abundance and range of abundance, respectively of the core phyla were as follows: Firmicutes (61%, 19 to 83%), Bacteroidetes (28%, 11 to 63%), Proteobacteria (3%, 0.34 to 17.5%), Tenericutes (0.15%, 0.0 to 0.35%), Nitrospirae (0.11%, 0.03 to 0.22%), and Fusobacteria (0.086%, 0.017 to 0.38%). Feeding DG-based diets resulted in significant shifts in the fecal microbial community structure compared with the traditional CON. Four low abundance phyla significantly responded to dietary treatments: Synergistetes (p = 0.01), WS3 (p = 0.054), Actinobacteria (p = 0.06), and Spirochaetes (p = 0.06).ConclusionsThis is, to our knowledge, the first study using this method to survey the fecal microbiome of beef cattle fed various concentrations of wet DG. Comparison of our results with other cattle DNA sequencing studies of beef and dairy cattle feces from a variety of geographical locations and different management practices identifies a core set of three phyla shared across all cattle. These three phyla, in order of relative abundance are; Firmicutes, Bacteroidetes, and Proteobacteria. The presence of large animal-to-animal variation in cattle microbiome was noted in our study as well as by others.

Escherichia coli O157:H7 Super-Shedder and Non-Shedder Feedlot Steers Harbour Distinct Fecal Bacterial Communities

“…Our dataset was estimated to cover more than 85% of the bacterial diversity present in feces (Figure 2). The bacterial community in all steers was dominated by Firmicutes , accounting for 53.9%, followed by Bacteroidetes at 35.6% of total sequences, a pattern observed by others [11], [12], [38]. With this depth, however, only a small proportion of OTUs (<1%, or 10–50 OTUs) were shared by all 22 samples at 97% similarity level (Figure 5; Table S3).…”

Pathophysiological evaluation of subacute ruminal acidosis (SARA) by continuous ruminal pH monitoring

“…Recently, pyrosequencing has been used for assessment of microbial composition in the rumen of cattle (Jami & Mizrahi 2012; Rice et al . 2012). These studies supported the notion that pyrosequencing facilitated greater understanding of microbial diversity.…”

Comparison of bacterial communities in faeces of beef cattle fed diets containing corn and wet distillers’ grain with solubles

“…2011). The feeding of a 10% corn‐ or 5–15% sorghum‐based distillers’ grain diet to 200 animals on five diets results in phylum‐level changes in the Synergistetes, WS3, Actinobacteria and Spirochaetes (Rice et al. 2012).…”