Influence of Cutting Intervals and Transition Periods on Chemical Composition Variability of Selected Tropical Grasses under Flooded Savanna Conditions of Arauca, Colombian Orinoquia
, Oscar Mauricio Vargas-Corzo 3, Pere M. Parés-Casanova 4 and Otoniel Pérez-López 5Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript described these native grasses constitute an important sustainable food resource for livestock in the flooded savanna ecosystem. It is suitable for publication in this journal, but there are still some questions.
1. There are too many references, please simplify it and keep it to 30-40.
2. The resolution of Figure is poor. You are advised to improve it.
3. The introduction should be shortened.
4. Some sentences have grammatical errors, please correct them.
Comments on the Quality of English LanguageModerate editing of English language required
Author Response
First reviewer’s responses
This manuscript described these native grasses constitute an important sustainable food resource for livestock in the flooded savanna ecosystem. It is suitable for publication in this journal, but there are still some questions.
Response. Dear reviewer,
The authors appreciate the insightful comments.
We attach the corrections and answers and were inserted into the text.
- There are too many references, please simplify it and keep it to 30-40.
Response: We consider that the number of references is adequate since it provides bibliographic support for all the content of the text; it reinforces the document about what has been written; makes consulted sources of information available to those who read the work
- The resolution of Figure is poor. You are advised to improve it.
Response: The figure was improved.
- The introduction should be shortened.
Response: The introduction was modified considering all the suggestions sent by the evaluators
- Some sentences have grammatical errors, please correct them.
Response: English was revised throughout the document
Moderate editing of English language required
Response: English was revised throughout the document
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis work evaluates the chemical composition variability of grasses grown in different physiographic positions of the flooded savanna at different cutting intervals and transition period. This manuscript is well organized. I think that it can be accepted after minor revision.
Other comments:
1. The abstract might be useful to either provide a lead-in sentence or clarify its direct relevance to the primary study aim.
2. The novelty of this work need be emphasize in "Introduction".
3. In "4. Discussion", it might benefit from highlighting the novelty and advantages of the method developed in this study compared to other known studies. The discussion need be further improved.
4. "Ca" and "Mg" need be corrected. "Ca2+" and "Mg2+"？
5. “5. Conclusions” was too preliminary. Important data need be provided. The advantage and disadvantage of this work need be summarized. The prospect for improving this work should be introduced.
Author Response
Second reviewer’s responses
This work evaluates the chemical composition variability of grasses grown in different physiographic positions of the flooded savanna at different cutting intervals and transition period. This manuscript is well organized. I think that it can be accepted after minor revision.
Other comments:
Response. Dear reviewer,
The authors appreciate the insightful comments.
We attach the corrections and answers and were inserted into the text.
- The abstract might be useful to either provide a lead-in sentence or clarify its direct relevance to the primary study aim.
Response: Modifications were made to the summary considering the number of words allowed.
- The novelty of this work need be emphasize in "Introduction".
Response: An attempt was made to emphasize the novelty of the study in the introduction.
- In "4. Discussion", it might benefit from highlighting the novelty and advantages of the method developed in this study compared to other known studies. The discussion need be further improved.
Response: a final paragraph highlighting the study results was described at the discussion section
- "Ca" and "Mg" need be corrected. "Ca2+" and "Mg2+"？
Response: corrected in the text
- “5. Conclusions” was too preliminary. Important data need be provided. The advantage and disadvantage of this work need be summarized. The prospect for improving this work should be introduced.
Response: your suggestion was taken into account
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsOverall, the article is arranged well and will contribute to the field. However, it still needs some minor corrections to enhance its quality for possible publication in this journal.
In the title, the authors mentioned tropical grasses, which is a very broad term while the authors analyzed nine native and introduced grasses? Would be better if change to selected tropical grasses?
Line 26: “(CP, Ash, EE, TDN, DMD, ME, P and S)” Please provide the full name for the abbreviations when appear first in the manuscript.
Line 49-54: Please modify this part as the paper is about chemical constituents of some selected grasses. For example make the connection of livestock and preferred fodder grass species.
2.2. Evaluated Grasses Species: Why authors choose these selected species?
Line 111: How many plots of 3 m x 3 m were established?
Line 121: How many plots were established for soil sampling? Which soil nutrients were analyzed?
Secondly, the authors evaluated the chemical composition variability of some introduced and native grasses from the floodplain ecosystem of the Colombian Orinoquia, at different cutting intervals and transition periods which is fine, but would be better to mention the adaptability of these species to different climatic conditions.
Results and Discussion
Would be better to arrange the discussion section in headings to make it easy and understandable for the readers such as;
Leaf, Stem and Total Biomass Dry Matter Yield of selected grasses?
Dynamics of Biomass across Cutting Cycles?
The investigated species can be used directly for grazing or conserved as silage or hay and is a reliable forage species that could represent a significant contribution to the livestock sector?
Please provide a concluding paragraph at the end of the discussion section that best summarizes and concludes your whole manuscript.
Please provide a recommendation at the end of the conclusion.
These grasses can be maintained up to which cutting cycle? i.e ist, 2nd….
Which species should be prioritized for dissemination to the livestock farming community that has higher nutritional value?
Which cutting cycle will affect the chemical composition, increase or decrease the yield and quality of species after which cutting cycle?
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
Third reviewer’s responses
Response. Dear reviewer,
The authors appreciate the insightful comments.
We attach the corrections and answers and were inserted into the text.
Overall, the article is arranged well and will contribute to the field. However, it still needs some minor corrections to enhance its quality for possible publication in this journal.
In the title, the authors mentioned tropical grasses, which is a very broad term while the authors analyzed nine native and introduced grasses? Would be better if change to selected tropical grasses?
Response: your suggestion was taken into account
Line 26: “(CP, Ash, EE, TDN, DMD, ME, P and S)” Please provide the full name for the abbreviations when appear first in the manuscript.
Response: corrected in the text
Line 49-54: Please modify this part as the paper is about chemical constituents of some selected grasses. For example make the connection of livestock and preferred fodder grass species.
Response: your suggestion was taken into account supplemented information between the mentioned paragraphs.
In the text it appears: “In the area, the livestock ac-tivity is performed under a traditionally extensive grazing condition to breed and raise cattle mainly with native grasses and some introduce pastures” [6,8].
2.2. Evaluated Grasses Species: Why authors choose these selected species?
Response: in the materials and methods section it was specified the following paragraph “These plants were selected as part of a project that aims to identify forage alternatives for the livestock activity in the region, considering its representativeness, animals acceptability and the opinion of farmers belonging to the Livestock Committee of the Region”.
Line 111: How many plots of 3 m x 3 m were established?
Response: “bank” (n = 15) and “low” (n = 12). It was corrected in the text
Line 121: How many plots were established for soil sampling? Which soil nutrients were analyzed?
Secondly, the authors evaluated the chemical composition variability of some introduced and native grasses from the floodplain ecosystem of the Colombian Orinoquia, at different cutting intervals and transition periods which is fine, but would be better to mention the adaptability of these species to different climatic conditions.
Response: To fully understand the soil characteristics of the evaluated area, a reference was provided from a previous study “Salamanca-Carreño, A.; Vélez-Terranova, M.; Vargas-Corzo, O. M.; Pérez-López, O.; Castillo-Pérez, A. F.; Parés-Casanova, P. M. Relationship of Physiographic Position to Physicochemical Characteristics of Soils of the Flooded-Savannah Agroecosystem, Colombia. Agriculture 2023, 13, 1-11.”(Ref. 10)
Results and Discussion
Would be better to arrange the discussion section in headings to make it easy and understandable for the readers such as;
Leaf, Stem and Total Biomass Dry Matter Yield of selected grasses?
Dynamics of Biomass across Cutting Cycles?
Response: your suggestion was taken into account.
The investigated species can be used directly for grazing or conserved as silage or hay and is a reliable forage species that could represent a significant contribution to the livestock sector?
Please provide a concluding paragraph at the end of the discussion section that best summarizes and concludes your whole manuscript.
Response: your suggestion was taken into account
Please provide a recommendation at the end of the conclusion.
Response: your suggestion was taken into account
These grasses can be maintained up to which cutting cycle? i.e ist, 2nd….
Which species should be prioritized for dissemination to the livestock farming community that has higher nutritional value?
Which cutting cycle will affect the chemical composition, increase or decrease the yield and quality of species after which cutting cycle?
Response: This information was included in the concluding paragraph
Minor editing of English language required
Response: English was revised throughout the document
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors1. What are the main grasses used to feed the animals in Colombia and what is the aim of production (milk, meat, egg etc.). What are the main drawbacks in grasses usage (monoculture, dryness)? How can we assess the quality of grasses? Please give a table to summarise the state of grasses.
2. Line 149: what are NDF AND ADF measuring? What is ethereal extract? Please define these grasses nutritional and mineral characteristic and what are they for?
3. Line 174. Table 2 Why was the CHNS not given?
4. Line 176: the different results of Dry matter between bank grasses and low grasses seems to be not significative. Did you use a statistical model to ensure if these results are significative. A lot of variables are being processed without a statistical model. It can mislead the conclusion from data results. We don’t know which variables are the most important
5. Line 316 NDF also allows to exhibits the extractable which contains lipids, proteins, etc. Why were these nutrients not measure in order to assess the nutrients quality of the grasses?
6. Line 436 why all the fraction from NDF is considered undigestible. That fraction has the extractable as mentioned above with lipids, protein and other fibres.
Author Response
Fourth reviewer’s responses
Response. Dear reviewer,
The authors appreciate the insightful comments.
We attach the corrections and answers and were inserted into the text.
What are the main grasses used to feed the animals in Colombia and what is the aim of production (milk, meat, egg etc.). What are the main drawbacks in grasses usage (monoculture, dryness)? How can we assess the quality of grasses? Please give a table to summarise the state of grasses.
Response: In Colombia, a great diversity of forages is used depending on the height above sea level where the system is located. In the ecosystem evaluated, mainly native species and some introduced species are used. Hence the importance of study given that they are not well known species.
In the introduction is specified that in the study area, production systems mainly focus on breed and raise cattle under extensive conditions. In the introduction we also indicate that the main drawbacks are the scarce knowledge about the yield and quality of forages resources used to feed grazing animal in different physiographic positions, growth phases and periods of the year. Finally, we study the grasses quality using the standard variables commonly used as indicator of grasses performance and composition.
- Line 149: what are NDF AND ADF measuring? What is ethereal extract? Please define these grasses nutritional and mineral characteristic and what are they for?
Response: Fiber and their fractions are extensively explained in the discussion section. Ethereal extract was deeper explained in the discussion section also.
- Line 174. Table 2 Why was the CHNS not given?
Response: we included TDN and DMD, and the soluble CHOs are included into these fractions. Create another variable would be correlated with these fractions and not contribute with new information to the analysis (collinearity).
- Line 176: the different results of Dry matter between bank grasses and low grasses seems to be not significative. Did you use a statistical model to ensure if these results are significative. A lot of variables are being processed without a statistical model. It can mislead the conclusion from data results. We don’t know which variables are the most important
Response: In this study it is not possible to directly compare between “low” and “bank” species since they are not the same grasses. A comparison could only be made between species of the same physiographic position, however that would make the document longer. We propose an analysis scheme that allows us to see everything together, even working with a considerable number of variables.
- Line 316 NDF also allows to exhibits the extractable which contains lipids, proteins, etc. Why were these nutrients not measure in order to assess the nutrients quality of the grasses?
Response: To evaluate the nutritional characteristics of forages we use the variables that are frequently used in studies of nutritional characterization of forage species, and that are used for rations formulation to herbivorous species given that they are positively correlated with animal performance. Likewise, the evaluated fractions were those that were calibrated in the NIRS (Near-Infrared Reflectance Spectroscopy), which was the measurement equipment.
- Line 436 why all the fraction from NDF is considered undigestible. That fraction has the extractable as mentioned above with lipids, protein and other fibres.
Response: In the study we call the fraction (NDF, lignin and HC) as partial digestible or undigestible. Precisely, the partially digestible part is attributed to NDF, since it is a fraction that can be partially degraded by the intestinal flora of ruminants.
Author Response File: Author Response.pdf
