Effects of Guanidinoacetic Acid on Ruminal Fermentation and Greenhouse Gas Production Using Fresh Forage and Silage from Different Maize (Zea mays L.) Genotypes
, Verónica Andrade-Yucailla 3, Mona Mohamed Mohamed Yasseen Elghandour 4, Néstor Acosta-Lozano 3, Marco Antonio Rivas-Jacobo 1, Daniel López-Aguirre 2, Jonathan Raúl Garay-MartÃnez 5, Paulina Vazquez-Mendoza 6, Marcos Barros-RodrÃguez 7,* and Abdelfattah Zeidan Mohamed Salem 4,*Round 1
Reviewer 1 Report
The authors investigated the effect of Guanidinoacetic Acid on In Vitro Ruminal Fermentation and Greenhouse Gas Production using Fresh Forage and Silage from Different Maize (Zea mays L.) Genotypes. Some concerns should be addressed before publication.
1. L54-L57, L59-L60, too long sentence, please rewrite it.
2. Change to “A viable alternative to deal with this problem is to manipulate of the diet…”
3. L71, What does ‘it’ refer to?
4. L76-L80, suggest to rewrite the sentence, too long and too hard to read it.
5. “and at the time of evaluation”，what's meaning？
6. L133-L134, change to “the neutral detergent fiber (NDF) and acid detergent fiber (ADF) were analyzed with the methodology…”
7. L160-L163, long sentence.
8. L226, L228, L230, why not use P <0.05 or P<0.01?
9. Within 0-24h, gas production is increasing at such a slow rate. Why? This is markedly different from the usual in vitro fermentation kinetics.
The English should be improved. There are too many sentences in the paper, and they are hard to read.
Author Response
RESPONSE LETTER
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Manuscript ID: |
fermentation-2366503 |
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Title: |
Effects of Guanidinoacetic Acid on In Vitro Ruminal Fermentation and Greenhouse Gas Production using Fresh Forage and Silage from Different Maize (Zea mays L.) Genotypes |
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Journal |
Fermentation |
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Section: |
Microbial Metabolism, Physiology & Genetics |
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Special Issue: |
In Vitro Digestibility and Ruminal Fermentation Profile |
Dear Assigned Reviewer,
We appreciate the time they devoted to reviewing our manuscript and the comments they made, the which undoubtedly served to improve the quality. We have made changes to the manuscript document based on your suggestions and using "change control", and below is a transcript of your suggestions in black and our responses to each suggestion in blue.
Sincerely,
The Author's
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Comments from the Reviewers to the Authors:
REVIEWER 1
The authors investigated the effect of Guanidinoacetic Acid on In Vitro Ruminal Fermentation and Greenhouse Gas Production using Fresh Forage and Silage from Different Maize (Zea mays L.) Genotypes. Some concerns should be addressed before publication.
- L54-L57, L59-L60, too long sentence, please rewrite it.
Response: We have restructured the sentence.
- Change to “A viable alternative to deal with this problem is to manipulate of the diet…”
Response: We already made the correction
- L71, What does ‘it’ refer to?
Response: We refer to the silage, the correction has already been made.
- L76-L80, suggest to rewrite the sentence, too long and too hard to read it.
Response: We have restructured the sentence.
- “and at the time of evaluation”，what's meaning？
Response: We mean GAA, the correction has already been made.
- L133-L134, change to “the neutral detergent fiber (NDF) and acid detergent fiber (ADF) were analyzed with the methodology…”
Response: We already made the correction.
- L160-L163, long sentence.
Response: We have restructured the sentence.
- L226, L228, L230, why not use P <0.05 or P<0.01?
Response: We consider it more appropriate to use the real value to know how close or removed it is from the defined significance level.
- Within 0-24h, gas production is increasing at such a slow rate. Why? This is markedly different from the usual in vitro fermentation kinetics.
Response: It is possible that it looks that way because the data that we present in the Figures and Tables are from the accumulated production at different incubation times, that is, the value of the current reading plus the previous one.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article "Effects of Guanidinoacetic Acid on In Vitro Ruminal Fermenta-2 tion and Greenhouse Gas Production using Fresh Forage and 3 Silage from Different Maize (Zea mays L.) Genotypes". The paper is in the interest of Fermentation, however there are several issues to be solved before publication:
1. The abstract is not concise and clear enough, and needs to be improved.
2. Would you explicitly specify the novelty of your work? What progress against the most recent state-of-the-art similar studies was made?
3. What about other types of additives? Does it have a similar effect, but with lower greenhouse gas emissions? These issues need to be considered and completed.
4. The introduction part needs to be revised. The author only introduces the GAA additive in the introduction, and here needs to add the effect comparison of other additives to illustrate the significance of studying GAA additives.
5. Table 1: Was the data in the table not tested in parallel? If not, the availability of such data is questionable. If parallel experiments were performed, please add error values to the table.
6. Error bars are missing for data in each Fig.
7. In the Results, it is necessary to add a literature comparison to show that the effects of other additives in the literature are compared with this study, and to further prove the usability of the additives in this study, a comparison table can be added.
Minor editing of English language required
Author Response
REVIEWER 2
The article "Effects of Guanidinoacetic Acid on In Vitro Ruminal Fermenta-2 tion and Greenhouse Gas Production using Fresh Forage and 3 Silage from Different Maize (Zea mays L.) Genotypes". The paper is in the interest of Fermentation, however there are several issues to be solved before publication:
- The abstract is not concise and clear enough, and needs to be improved.
Response: We appreciate your recommendation; we have improved the abstract.
- Would you explicitly specify the novelty of your work? What progress against the most recent state-of-the-art similar studies was made?
Response: We believe that the novelty of this work is in the quantification of greenhouse gases (GHG) using GAA as an additive and corn forage (a very common ingredient in cattle diets), as well as demonstrating that GAA does not increase GHG.
- What about other types of additives? Does it have a similar effect, but with lower greenhouse gas emissions? These issues need to be considered and completed.
Response: We appreciate your suggestion, but considering that we only evaluate GAA, we believe that mentioning other additives is outside the scope of the stated objective and is unnecessary.
- The introduction part needs to be revised. The author only introduces the GAA additive in the introduction, and here needs to add the effect comparison of other additives to illustrate the significance of studying GAA additives.
Response: We appreciate your recommendation, but feel it is more important to highlight the reported benefits of GAA use in animals, as outlined in paragraph three of the introduction.
- Table 1: Was the data in the table not tested in parallel? If not, the availability of such data is questionable. If parallel experiments were performed, please add error values to the table.
Response: Table 1 only shows the characterization of the chemical composition of the fresh forage and corn silage, since it was not the object of study in this investigation and therefore, these data were not statistically analyzed.
- Error bars are missing for data in each Fig.
Response: We have already added the error bars in all Figures, we appreciate your observation.
- In the Results, it is necessary to add a literature comparison to show that the effects of other additives in the literature are compared with this study, and to further prove the usability of the additives in this study, a comparison table can be added.
Response: We appreciate your comments, but as indicated by our objective, we evaluated the in vitro production of total gas, CH4, CO and H2S, as well as rumen fermentation characteristics and CH4 conversion efficiency of fresh forages and silages of different genotypes maize, with and without the addition of GAA. Therefore, we consider it inappropriate to compare this additive with others.
Author Response File: Author Response.pdf
Reviewer 3 Report
Specific comments and questions:
The presented article is relevant because it concerns environmental issues, especially important nowadays - the production of greenhouse gases during in vitro fermentation of feed.
Maize (l. 68) or corn (l. 64), which term, American or English do you prefer?
In terms of the results in Table 1:
- It is not clear is there any significant differences between controlled parameters of the chemical composition. The explanation given of these results is very, very short and not sufficient. And more, it is necessary to add the number of the samples analyzed in the title of the table.
The numbering of the Tables as it is now is wrong, there are now two tables numbered 4.
Tables 3 and 4, which are for CH4 production, contain repeated information on CH4 production calculated as mL gas 100 mL-1 gas. In this regard, there are two possible options:
- Option 1: In Table 3, the data for kinetic parameters and CH4 production presented as mL gas g-1 DM incubation should remain only (CH4 production presented as mL gas 100 mL-1 gas to drop out), Table 4 should remain unchanged.
- Option 2: Table 4 should now be dropped altogether, and the authors adding in the text an explanation for calculating methane in "g gas kg-1 DM for 4, 24 and 48 h”
It`s up to you!
As we have already said, the information included in the tables is very large: many factors, many parameters, several interactions. Therefore, it may be better, for a clearer and faster orientation, to show in bold the significant differences where they exist.
The discussion: a very good attempt has been made to highlight the role of each controlled parameter in the physiological function of the gastrointestinal tract of animals, as well as to explain the results obtained. In the explanation of all parameters, emphasis is placed on the influence of GAA addition. Overall, the discussion is very successful.
Regarding the conclusion drawn: my opinion is that the effectiveness of each evaluated factor on the relevant indicators is adequately reflected.
Author Response
REVIEWER 3
The presented article is relevant because it concerns environmental issues, especially important nowadays - the production of greenhouse gases during in vitro fermentation of feed.
Maize (l. 68) or corn (l. 64), which term, American or English do you prefer?
Response: It's maize, the correction has already been made.
In terms of the results in Table 1:
- It is not clear is there any significant differences between controlled parameters of the chemical composition. The explanation given of these results is very, very short and not sufficient. And more, it is necessary to add the number of the samples analyzed in the title of the table.
Response: Table 1 only shows the characterization of the chemical composition of the fresh forage and corn silage, since it was not the object of study in this investigation and therefore, these data were not statistically analyzed. In addition, we take your comment into account and add the number of samples analyzed in the title of the Table.
The numbering of the Tables as it is now is wrong, there are now two tables numbered 4.
Response: That's right, we already removed the wrong one.
Tables 3 and 4, which are for CH4 production, contain repeated information on CH4 production calculated as mL gas 100 mL-1 gas. In this regard, there are two possible options:
- Option 1: In Table 3, the data for kinetic parameters and CH4 production presented as mL gas g-1 DM incubation should remain only (CH4 production presented as mL gas 100 mL-1 gas to drop out), Table 4 should remain unchanged.
- Option 2: Table 4 should now be dropped altogether, and the authors adding in the text an explanation for calculating methane in "g gas kg-1 DM for 4, 24 and 48 h”
Response: We appreciate the suggestions, we're sorry, it was our mistake, but we already deleted the wrong Table.
It`s up to you!
As we have already said, the information included in the tables is very large: many factors, many parameters, several interactions. Therefore, it may be better, for a clearer and faster orientation, to show in bold the significant differences where they exist.
Response: We appreciate your recommendation, we have taken it into account, and we highlight in bold the significant differences in each Table.
The discussion: a very good attempt has been made to highlight the role of each controlled parameter in the physiological function of the gastrointestinal tract of animals, as well as to explain the results obtained. In the explanation of all parameters, emphasis is placed on the influence of GAA addition. Overall, the discussion is very successful.
Response: We appreciate positive feedback.
Regarding the conclusion drawn: my opinion is that the effectiveness of each evaluated factor on the relevant indicators is adequately reflected.
Response: We appreciate positive feedback.
Author Response File: Author Response.pdf
