Screening and Functional Prediction of Rumen Microbiota Associated with Methane Emissions in Dairy Cows

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Introduction
The description of lase methane detection (LMD) should come in the
materials and methods and not in the introduction.


Materials and methods

There is no reference to the Simpson and Pielou indices.


Results

Table 1 - units are missing.
Rows 393 to 396 - how do they measure cell membrane transport?
membrane transport?

Discussion
Lines 393 to 396 How do you know that transport is carried out by the
membrane.
Lines 407 to 410 - If the diet is the same in both groups, how can the
groups, how is there physiological adaptation of the microbiotic community in the
GROUP.

Lines 413 to 417 - Archaea and protozoa are the main emitters of enteric methane, why haven't they been studied?

The two groups of microorganisms studied are not important enough to study global enteric methane production.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents an interesting and relevant study on the association between rumen microbiota and methane emissions in dairy cows. The research is timely, given the global emphasis on reducing greenhouse gas emissions from livestock. The authors have utilized both microbial diversity analysis and functional prediction approaches, offering valuable insights into the ruminal microbial communities linked to high and low methane emissions. The use of a large sample size strengthens the study's conclusions, although some methodological aspects and result interpretations require further clarification and discussion. Below are specific comments and suggestions for improving the manuscript.

1. The introduction provides a strong rationale for studying methane emissions in dairy cows but would benefit from further clarification on how this study builds on or contrasts with previous studies, particularly those on functional prediction using meta-omics.

2. The use of the Laser Methane Detector (LMD) is well explained, but it would be helpful to discuss in more detail how the LMD data compares with other methane measurement methods, such as respiration chambers, and whether any calibration was performed for accuracy across different measurement tools.

3. More explanation is needed regarding the statistical models used to analyze microbial diversity indices and methane emissions. Did the authors control for factors such as parity, milk yield, and diet, which could influence methane emissions and microbiota composition?

 

4. The discussion would benefit from a more in-depth exploration of the mechanisms by which the enriched microbial functions in high methane emitters might contribute to greater methane production. Moreover, consider elaborating on the potential applications of these findings for methane mitigation strategies.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This study presents a significant contribution to understanding methane emissions in dairy cattle by leveraging advanced portable measurement devices and systematically assessing rumen microbial communities across a large Holstein population. The findings highlight important correlations between microbial diversity, particularly the role of Bacteroidetes, and methane production, offering valuable insights into the microbial mechanisms underlying greenhouse gas emissions. This research is especially relevant for readers interested in mitigating methane emissions, as it proposes potential microbial targets for intervention. However, addressing the limitations regarding archaea, fungi, and phenotypic measurement methods will further enhance its impact.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have made some changes to the article, but I don't think they have answered some of the questions, for example, how they justify Bacteroidales and Prevotellacea emitting high concentrations of methane, but they don't mention that methanogenic archaea are the main emitters of methane in rummies

Author Response

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Author Response File: Author Response.docx