Dairy cows at a feed bunk

February 04, 2026

How's Your (Microbial) Core Strength?

All ruminants, including dairy cattle, rely on rumen microbes to convert their feed into nutrients they can absorb. While each cow is home to thousands of microbial species, the exact community makeup differs from animal-to-animal based on cow genetics, diet, and early life upbringing.

A recent global study spanning 35 countries found that despite the extraordinary breadth of different microbes found in the rumen, a small set of microbes found in almost all cows have an outsized importance1. Tovar-Herrera et al. found that out of well over 400 total identified genera, a group of just 14 microbial genera were present in over 80% of animals — together, these microbes are known as the core rumen microbiome. And these core microbes represent the functional backbone of the rumen ecosystem.

By comparing the genomes of the core ruminal bacteria to all other ruminal bacteria, the authors found a few key features that are the hallmark of their widespread success.

First off, the core microbes had larger genomes than non-core microbes, by roughly 15% — on average, this translates to an additional 300 genes. They also had broader metabolic capacity, meaning they were able to survive on a more diverse range of nutritional building blocks than non-core members. And they contained specialized genetic pathways that allowed them to synthesize amino acids that are necessary for both non-core microbes and the cow herself. In other words, these microbes help build and stabilize the entire rumen system.

This helps explain why shifts in the rumen microbiome can have meaningful impacts on cow performance. A more stable and functionally capable microbial community leads to more consistent fermentation, improved energy production, and ultimately better feed efficiency.

Galaxis Frontier is the only product containing live microbes that are part of the core rumen microbiome. Supplementation with Galaxis Frontier has been shown to shift rumen microbial function and increase microbiome consistency across animals (Figure 1). These changes help to explain why feeding Galaxis Frontier to dairy cattle increased ruminal propionate concentrations and feed efficiency in eight out of eight independent academic trials2–9.

To find out more on how to strengthen your (microbial) core, reach out!

Figure 1: Phylogenetic-RPCA plot showing tighter clustering of rumen microbiomes in cows supplemented with Galaxis Frontier compared to control cows.
Figure 1. Supplementation with Galaxis Frontier tightened the rumen microbiome, inducing treated cows to look more similar than control cows. Shotgun DNA sequencing analysis of rumen fluid samples collected 10 weeks into the trial by Marinho et al., 2024.

CITATIONS

  1. Tovar-Herrera OE, Grinshpan I, Sorek G, Lybovits I, Levin L, Moraïs S, Mizrahi I. Core rumen microbes are functional generalists that sustain host metabolism and gut ecosystem function. Nature Ecology & Evolution. 2025 Dec 1:1-5.
  2. Dickerson et al., 2022, J. Dairy Sci.
  3. Bulnes et al., 2025, J. Dairy Sci.
  4. Valldecabres et al., 2025, J. Dairy Sci.
  5. Marinho et al., 2024, J. Dairy Sci.
  6. Valldecabres et al., 2022, J. Dairy Sci.
  7. Goldsmith et al., 2023, J. Dairy Sci.
  8. Ferro et al., 2022, ADSA poster.
  9. Tabor et al., 2025, J. Dairy Sci.
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