Growth Performance and Rumen Microbiota of Sheep Respond to Cotton Straw Fermented with Compound Probiotics
and Ping Gong 1,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis study provides an insight into how fermented cotton straw could enhance the growth performance of sheep by increasing the abundance of bacteria associated with the utilization of protein, carbohydrates, and other nutrients. These findings may be conducive to advancements in the livestock industry. However, there are several concerns that need to be addressed. Please review the manuscript again, as there are some typos and grammatical errors that distract from the main subject.
Introduction: The introduction should mention research on the use of cotton straw or similar materials for fermentation in sheep feed. It should also elaborate on the challenges of using cotton straw as a feed resource and explain why biological fermentation is particularly suitable for addressing these challenges.
Materials and Methods: If the probiotic used in the study has a CGMCC number, it is recommended that it be included. The trial mentions 'Stage 1' and 'Stage 2,' but the experimental setup could be explained in more detail to clarify the rationale for these phases.
Discussion: Although studies have shown significant differences in rumen microbiota among treatment groups, further analysis could explore how these differences are related to physiological processes such as sheep growth performance and digestive efficiency. For example, is the increase in abundance of Prevotella bacteria closely correlated with protein and carbohydrate metabolism? Such in-depth biological explanations would strengthen the completeness of the discussion.
Conclusions: While the conclusion is concise and clear, it would benefit from additional discussion of potential future research directions or practical applications, particularly in the context of sustainable feed development for livestock.
Additionally, the following points need clarification:
1. Lines 73-76 lack sufficient details about the probiotic strain, including its isolation source, storage number, and relevant references.
2. In lines 91-93, the study mentions the "stage 1" and "stage 2", but the experimental setup can be explained in more detail to clarify the basic principles of these stages.
3. On line 99, the specific composition or modifications of MIC (microbiome) and MEY (mixed microbial and enzyme preparation group) components require further elaboration.
4. In Table 1, the dietary formula uses fermented cotton straw instead of cotton leaves. What are the specific components of cotton leaves? As mentioned in the article, the CP content of straw increases after fermentation. Why is the overall CP content of the diet decreased after substitution?
5. In the experimental design, it is necessary to describe the purpose of establishing MIC and MEY groups, as well as the relationship between the dosage of these two groups in the diet and the amount of bacteria added to fermented straw.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript explores the fermentation of cotton straw using using compound probiotics (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) as a feed resource for sheep. The fermentation improved the nutrients and hygienic indices. The feeding trial were tested and the rumen microbiota profiles were also analyzed.
The following suggestions are offered for revision.
Line 70~71
The concentration (CFU/mL) of Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae should be presented.
Line 107
Yeast should be Saccharomyces cerevisiae.
Line 108
What is (DM)?
Line 113~114
The full names of VA, VD and VE should be presented.
Line 116
HFC: High-proportion
Line 120
Feed proximate analyses were in accordance with AOAC (2010).
The reference should be cited.
Line 122
Free gossypol (FG) was measured in accordance with GB/T 13086-2020
The reference should be cited.
Line 184 (Table 2)
The methods for the determination of CP, NDF and ADF should be presented.
Line 210
HFC: High-proportion
Line 216
“For GH, all treatment groups significantly enhanced its level (p < 0.05).”
But it was not in group MEY.
Please check the correctness.
Line 226
BHBA, b-Hydroxybutyric acid
Line 236
The method for the determination of sheep rumen fluid pH should be presented.
Line 245
HFC: High-proportion
Line 263
The resolution of Figure 2 is not enough. The authors should provide higher resolution figures.
Line 290
The resolution of Figure 4 is not enough. The authors should provide higher resolution figures.
Line 324~326
“UREA is an indicator of feed protein utilization and body protein metabolism in sheep28. In this study, the UREA levels in the treatment groups were higher, suggesting enhanced utilization of feed protein29.”
However, all treatment groups significantly reduced the levels of UREA in stage 2. Please discuss it.
Line 355
The full name of VFA should be presented.
Line 360
Why the authors did not present the data of alpha diversity, indices such as Sobs, Chao1, and ACE?
Line 364
The data of The Shannon index and Shannoneven indices should be presented.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors response well, so I have no more suggestion.
