Evaluation of Associative Effects on Degradability, Fermentation Parameters, and In Vitro Methane Production as a Result of Variation in the Ruminants Diets Constituents

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

SPECIFIC COMMENTS

INTRODUCTION

Lines 35-38. Throughout this section, the authors state that ruminal fermentation has been greatly manipulated over several decades to minimize the production of methane gas (CH4), by increasing the amount of concentrate feed in the diet to increase nutrient utilization, which improves animal productivity and reduces environmental impacts. However, I would appreciate that the authors should mention, with citations, that the reduction of ruminal methane emissions can also be achieved through other feeding alternatives, such as the use of balanced diets, the use of additives with antimethanogenic potential, the use of foliage and fruits from trees or shrubs or the use of better quality forages, among others.

 

MATERIAL AND METHODS

No comment.

 

RESULTS

In the footnote of Table 2 it says: Means followed by the different letters capital letters (crops) and letters lowercase (forage to concentrate ratio) differ ….

I suggest: Means followed by the different capital letters (forages) and lowercase letters (forage to concentrate ratio) differ ….

Lines 294-295. What do CB1, CB2 and CB3 mean?

Lines 223-226. … (P < 0.0001) than in the silages of corn and pineapple crop waste

Must say: … (p < 0.001) than in the silages of corn and pineapple crop waste.

Lines 222, 224. In the significance levels P ˃ 0.05, P ˂ 0.0001 and P ˂ 0.05 of the footnote in Table 3, the capital letter P is used; in all cases, P should be standardized and the letter p ˃ or p ˂ lowercase should be written.

Lines 232-233. I would suggest that the authors compare the percentage decreases in methane production from the 100:00 and 10:90 ratios for corn silage, Tifton hay, and pineapple crop waste silage.

In the text and tables, authors should review and standardize the use of statistical differences of ˂ 0.001, which is repeatedly written as ˂.001

In Table 2 the Forage p-value of ME and NE is expressed as ˂.0001, while in the text it is noted as p ˂ 0.001. Please review and correct.

In Table 2 the p-value Forage-to-concentrate ratio of IVDMD, GP, ME and NE is expressed as ˂.001, while in the text it is noted as p ˂ 0.001. Please review and correct.

In Table 3 the p-value Forage of HAc, CO2 and CH4 is expressed as ˂.001, while in the text it is noted as p ˂ 0.001. Please review and correct.

In the footnotes of Tables 2 and 3, significant differences are indicated by the Tukey test (P ˂ 0.05); however, for some of the noted means, significance levels of p ˂ 0.001 are indicated. Please review and correct.

 

DISCUSSION

In this section, I would like that authors discuss more widely the use of different forage sources to reduce CH4 emissions. In this regard, I would suggest that authors include further discussion about the importance and practical implications of using different forage souces on methane production.

It is significant that methane emissions varied with the different evaluated forages, particularly the obtained emissions with the use of crop waste. Therefore, I would appreciate that the authors highlight the importance of the best forage found to reduce methane emissions.

Besides the addition of concentrate to diets, the reduction of methane emissions by ruminants can be achieved through other feeding alternatives, such as the use of balanced diets, use of additives with antimethanogenic potential or use of foliage and fruits from trees or shrubs, among others. In this regard, I would suggest that the authors discuss the possibilities of reducing methane emissions through the use of better quality forages.

Finally, I would suggest that the authors discuss some limitations of the study.

 

REFERENCES

References on some topics (e.g. methane production, rumen fermentation, acidosis, and others) should be updated.

 

Author Response

Attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Table 1， the unit.

Figure 1, provided SEM.

Table 2, superscript the letter.

The reference need to revise according to the author guildline.

Doubel and need explained the concentrate to forage ration?

 

Author Response

Attached.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

It is an exciting research. Nevertheless, explaining some issues related to the methodology and results and discussing them in more detail is necessary.

Comments for author File: Comments.pdf

Author Response

Attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The article has been significantly improved, but it still lacks clarity on how the redox potential was measured and calculated.

Author Response

The article has been significantly improved, but it still lacks clarity on how the redox potential was measured and calculated.

Suggestions accepted. Thank you.