Fecal Microbiome Differences in Angus Steers with Differing Feed Efficiencies during the Feedlot-Finishing Phase

Abstract

The gastrointestinal microbiota of cattle is important for feedstuff degradation and feed efficiency determination. This study evaluated the fecal microbiome of Angus steers with distinct feed efficiencies during the feedlot-finishing phase. Angus steers (n = 65), fed a feedlot-finishing diet for 82 days, had growth performance metrics evaluated. Steers were ranked based upon residual feed intake (RFI), and the 5 lowest RFI (most efficient) and 5 highest RFI (least efficient) steers were selected for evaluation. Fecal samples were collected on 0-d and 82-d of the finishing period and microbial DNA was extracted and evaluated by 16S rRNA gene sequencing. During the feedlot trial, inefficient steers had decreased (p = 0.02) Ruminococcaceae populations and increased (p = 0.01) Clostridiaceae populations. Conversely, efficient steers had increased Peptostreptococcaceae (p = 0.03) and Turicibacteraceae (p = 0.01), and a trend for decreased Proteobacteria abundance (p = 0.096). Efficient steers had increased microbial richness and diversity during the feedlot period, which likely resulted in increased fiber-degrading enzymes in their hindgut, allowing them to extract more energy from the feed. Results suggest that cattle with better feed efficiency have greater diversity of hindgut microorganisms, resulting in more enzymes available for digestion, and improving energy harvest in the gut of efficient cattle.

The impact of different diets and genders on fecal microbiota in Hanwoo cattle

“…Since Paeniclostridium , Romboutsia , and Turicibacter belong to the Firmicutes phylum, a higher abundance of these genera in steers fed the late fattening TMR diet may contribute to the F/B ratio increase, which is positively correlated with the average daily gain [ 29 ]. This is supported by the association between Turicibacter and a high feed efficiency [ 11 , 37 ]. The increase in many minor bacterial species within Firmicutes may also contribute to the F/B ratio increase.…”

“…Alistipes is a core genus that is commonly found in the feces of cattle, but its function requires further investigation [ 7 , 16 , 36 ]. Previous studies showed that Turicibacter is more abundant in cattle with a high feed efficiency [ 11 , 37 ]. Since steers have a greater average daily gain compared to heifers, the abundance of Turicibacter is thought to be the greatest in Hanwoo steers fed a late fattening diet in the present study.…”

“…Recently, the Illumina MiSeq or HiSeq platform, which can produce numerous sequence reads, was applied to investigate the fecal microbiota composition in cattle. Various studies have been conducted to investigate and compare the fecal microbiota composition related to different beef production systems [ 10 ], different feed efficiencies [ 5 , 11 ], core microbiota investigations [ 12 ], grazing and feedlot cattle comparisons [ 13 ], management units in dairy cattle [ 14 ], dairy calves [ 15 ], and dairy cattle during early lactation [ 16 ]. These studies indicated that the fecal microbiota in cattle can be affected by various factors such as diet, age, individuals, breed, regions, and environments.…”

— Invited Review — Assessment of the gastrointestinal microbiota using 16S ribosomal RNA gene amplicon sequencing in ruminant nutrition

“…Similar to findings for the rumen, there is a possible link between feed efficiency and the fecal microbiota in cattle. Some studies indicated that the fecal microbiota composition differed between high- and low-feed efficiency cattle [ 54 , 55 ]. Lourenco et al [ 54 ] compared fecal microbiota between efficient and inefficient Angus steers during the feedlot-finishing stage.…”

“…Some studies indicated that the fecal microbiota composition differed between high- and low-feed efficiency cattle [ 54 , 55 ]. Lourenco et al [ 54 ] compared fecal microbiota between efficient and inefficient Angus steers during the feedlot-finishing stage. Their results showed that Ruminococcaceae and Clostridiaceae were decreased in inefficient Angus steers, whereas Peptostreptococcaceae and Turicibacteraceae were increased in efficient Angus steers during the feedlot-finishing stage ( Table 1 ).…”