Microbial Community and Fermentation Quality of Alfalfa Silage Stored in Farm Bunker Silos in Inner Mongolia, China

Round 1

Reviewer 1 Report

Dear Dr Chao Wang

The manuscript entitled is a descriptive study about microbial community and fermentation quality of alfalfa silage stored in farm bunker silos in a cold and humid  regions of Mongolia. The manuscript provides interesting information on the subject. However, in my opinion, few details must be corrected in order for this paper to be published.

Comments are below

Abstract:

L13: Please, rewrite as: Alfalfa is conserved in a silos type bunker in the cold..

L17: Specify as: in 72 samples collected from 12 farms located in 4 regions localized in three different latitudes and 4 different longitudes. Samples were coded according to region as…  

L19: Describe first where do samples A, B, etc. come from? Due to the nature of the site in which sampling was taken, coding by literals is not the most proper. Please define sampling site according to climatic variables (i.e., warm-dry, warm-rainy, cold-dry, cold-rainy)

L26: In contrast, the pH, NH3-N, and butyric acid concentrations were strongly associated (P < 0.01) with the presence of Clostridium estertheticum.

Introduction

L68: TMR?

Materials and methods

L95-96: Please, include here the climatic conditions prevailing in each region.

Table 2: What does mean the values 2,3- and 1,2- in Butyric and Butanediol

Butanediod and propanediod instead butanediol and propanediol?

Conclusion

L405: Could define the sampling sites in another way, the code by letters is not optimal for clarity to the reader. I strongly recommend that sites be defined, for example, using W=warm, C=cold, D=dry and R=rainy. In such a manner that warm and high humidity sites are defined as WR, this is only an idea. The decision is yours.

Author Response

Dear Reviewers:

Thank you for the reviewers’ comments regarding our manuscript. The comments were valuable and helpful to improve our manuscript as well as the significance of the study results. We have further edited the manuscript, and the revised portions are marked red in the text. Responses to reviewers’ comments are listed below.

We believe that we have improved the manuscript based on the reviewers’ comments. These changes do not influence the content and framework of our study. We also hope that with these improvements, our manuscript is now acceptable for publishing.

Thank you very much for your work concerning our paper.

Q1: L13: Please, rewrite as: Alfalfa is conserved in a silos type bunker in the cold.

A: As reviewers’ suggestion, we have modified this sentence. Please see L 13.

Q2: L17: Specify as: in 72 samples collected from 12 farms located in 4 regions localized in three different latitudes and 4 different longitudes. Samples were coded according to region as.

A: Considering the reviewers’ suggestion, we have modified this sentence. Please see L 16-17.

Q3: L19: Describe first where do samples A, B, etc. come from? Due to the nature of the site in which sampling was taken, coding by literals is not the most proper. Please define sampling site according to climatic variables (i.e., warm-dry, warm-rainy, cold-dry, cold-rainy).

A: As reviewers’ suggestion, we have modified this sentence. Please see L 18-20.

Q4: L26: In contrast, the pH, NH3-N, and butyric acid concentrations were strongly associated (P < 0.01) with the presence of Clostridium estertheticum.

A: Thank you for your professional comment. We have modified this sentence. Please see L 28-29.

Q5: L68: TMR?

A: We changed the abbreviation to the full name. Please see L 71.

Q6: L95-96: Please, include here the climatic conditions prevailing in each region.

A: We have added the climatic condition. Please see L 101-105.

Q7: Table 2: What does mean the values 2,3- and 1,2- in Butyric and Butanediol

Butanediod and propanediod instead butanediol and propanediol?

A: There are four isomers of butanediol, namely 1,2- butanediol, 1,3- butanediol, 1,4- butanediol and 2,3- butanediol. There are two isomers of propanediol, namely 1,2- propanediol and 1,3- propanediol. Refer to some previous studies, 2,3- butanediol and 1,2- propanediol are important indicators of silage fermentation quality because some microorganisms decompose water soluble carbohydrates to produce 2,3- butanediol and 1,2- propanediol to inhibit harmful microorganisms and improve the aerobic stability of silage.

Li, Y., and Nishino, N. (2011). Monitoring the bacterial community of maize silage

stored in a bunker silo inoculated with Enterococcus faecium, Lactobacillus

plantarum and Lactobacillus buchneri. J. Appl. Microbiol. 110, 1561–1570.

Muck, R. E., Nadeau, E. M. G., McAllister, T. A., Contreras-Govea, F. E., Santos, M.

C., and Kung, L. Jr. (2018). Silage review: Recent advances and future uses of silage additives. J. Dairy Sci. 101, 3980–4000.

Q8: Could define the sampling sites in another way, the code by letters is not optimal for clarity to the reader. I strongly recommend that sites be defined, for example, using W=warm, C=cold, D=dry and R=rainy. In such a manner that warm and high humidity sites are defined as WR, this is only an idea. The decision is yours.

A: Thank you for your professional advice. We defined the sampling sites in another way. Please see L 18-20, L 102-109, figure 1, table 1 and table 2.

Q9: If one of the referees has suggested that your manuscript should undergo extensive English revisions, please address this issue during revision. We propose that you use one of the editing services listed at https://www.mdpi.com/authors/english or have your manuscript checked by a colleague fluent in English writing.

A: Thanks for the pointing this out. Due to the limited time available to do this revision, we decided to ask to a native speaker who is employed in the company to read the article and we would thank him for that. The revision concerned only minor corrections (e.g.: minor grammatical errors, words in singular/plural, no correct verb forms, etc.). We have added certificate of English editing in the attached file. Please see that revised portions are marked red in the text.

Reviewer 2 Report

lines 95 and 96 were fresh and frozen samples from same cutting, i.e. were fresh sampled collect and then fermented samples collected after a fermentation period?

36 samples from 12 farms does this mean 3 replications of same silage or 3 different silages from each farm?

What was the length of fermentation period of fermented samples. is this what is meant in line 105?

Can any management practices explain the high clostridium in A, B, and H? How fast were the bunkers filled? what was the packing density of the silages?

Author Response

Dear Reviewers:

Thank you for the reviewers’ comments regarding our manuscript. The comments were valuable and helpful to improve our manuscript as well as the significance of the study results. We have further edited the manuscript, and the revised portions are marked red in the text. Responses to reviewers’ comments are listed below.

We believe that we have improved the manuscript based on the reviewers’ comments. These changes do not influence the content and framework of our study. We also hope that with these improvements, our manuscript is now acceptable for publishing.

Thank you very much for your work concerning our paper.

Q1: lines 95 and 96 were fresh and frozen samples from same cutting, i.e. were fresh sampled collect and then fermented samples collected after a fermentation period?

A: Thank you for your professional comment. Fresh and frozen samples collected from same cutting. Fresh sample collected before ensiling. Fermented sample collected after 60 days ensiling.

Q2: 36 samples from 12 farms does this mean 3 replications of same silage or 3 different silages from each farm?

A: We collected 3 different silages from each farm.

Q3: What was the length of fermentation period of fermented samples. is this what is meant in line 105?

A: Thanks for the pointing this out. The length of fermentation period of fermented samples was 60 days. We have modified this sentence. Please see L 110-111.

Q4: Can any management practices explain the high clostridium in A, B, and H? How fast were the bunkers filled? what was the packing density of the silages?

A: Loose compaction or sealing may cause the high clostridium in A, B, and H. It takes 34 hours to filled the bunker. The packing density of the silages was about 550 kg/m³.