Increased Yearling Weight Gain Is Associated with a Distinct Faecal Microbial Profile

Area of Science:

• Animal Science
• Microbiology
• Genomics

Background:

• Gut microbial communities play a crucial role in livestock physiological processes and production traits.
• Animal production traits, particularly growth performance, are vital for the profitability of livestock enterprises.
• Previous research suggests a correlation between gut microbiota composition and growth performance in livestock.

Purpose of the Study:

• To characterize and compare the fecal microbial profiles of Angus steers exhibiting high and low average daily gain (ADG).
• To investigate these microbial differences at both the weaning and yearling stages of development.
• To determine if gut microbiota composition is associated with growth performance differences in beef cattle.

Main Methods:

• Rectal fecal samples were collected from Angus steers categorized by high and low ADG.
• 16S rRNA gene sequencing was employed to profile the microbial communities.
• Analyses included comparisons of relative abundances, LEfSe, alpha diversity (species richness), and beta diversity (phylogenetic similarity).

Main Results:

• Few significant microbial differences were observed between high and low ADG groups at the weaning stage.
• At the yearling stage, significant differences in microbial profiles emerged between high and low ADG groups.
• Eight phyla and six genera showed significantly different relative abundances; species richness decreased in the high ADG group (p=0.001), and beta diversity clearly separated the groups (p=0.005).

Conclusions:

• Gut microbial profiles differ significantly between Angus steers with high and low average daily gain, particularly at the yearling stage.
• Reduced species richness and altered phylogenetic similarity in the gut microbiota are associated with higher growth performance (ADG).
• These findings highlight the potential of targeting gut microbiota for enhancing growth performance in beef cattle.