The Basics of Clinical Nutrition for Compromised Ruminants—A Narrative Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The topic of this review is novel and worth trying. It provides comprehensive information on the clinical nutrition of compromised ruminants. The flow of the writing and ideas is clear. It is a well-detailed review. 

Specific comments:

• The abstract is shallow, lacks recommendations, and results of the review. Additionally, a summary or conclusion statement should be included.
• Many places in the review need references to support the mentioned information, such as 32-37, 39-43, 44-48, 62-77, 85-89, 96-103, 278-286, 431-442, 473-481, 568-575, ...ect
• Please provide references to support what is in the figures and Tables (Provide them in the footnote) 
• Why is there a duplication on some subheadings, such as in lines 324, 597, 671, 7575? 

Overall, the English level of writing is excellent 

 

Author Response

Reviewer 1:

Comments and Suggestions for Authors

The topic of this review is novel and worth trying. It provides comprehensive information on the clinical nutrition of compromised ruminants. The flow of the writing and ideas is clear. It is a well-detailed review. 

Specific comments:

• The abstract is shallow, lacks recommendations, and results of the review. Additionally, a summary or conclusion statement should be included. Thanks for your comment. We have reviewed the abstract and added or adjusted the text (L22 – 23, L31-36, and L38-39).
• Many places in the review need references to support the mentioned information, such as 32-37, 39-43, 44-48, 62-77, 85-89, 96-103, 278-286, 431-442, 473-481, 568-575, ...ect Thanks for your comment. We have reviewed the text and added reference whenever specific information was provided. However, some of the statements were general knowledge and no references are provided (Green front text).
• Please provide references to support what is in the figures and Tables (Provide them in the footnote) We have done this for Table 1, that is based on information from only a few sources. Other figures and tables are our original work that we cannot cite specific references for.
• Why is there a duplication on some subheadings, such as in lines 324, 597, 671, 7575? All address different subheadings

Reviewer 2 Report

Comments and Suggestions for Authors

I am concerned that this manuscript does not meet the standard criteria for publication in a highly reputable journal. Please consider the following comments and suggestions: 

1. Figure 1 ==> Step 4 "Pharmaconutrients" is misspelled
2. Chapter 3 ==> reccomending to perform a systematic review with more quantitative data on nutrient utilization in compromised ruminants, detailing the animal type (small/big ruminant), growth/production phase, pathology/negative effect on health and/or production. This would give a more organized overview on the existing studies and information in this area.
3. Line 366 - review the wording
4. Chatpter 4. should also be included in the systematic review, as mentioned for Chapter 3.
5. line 423-424 ==> Please reconsider this statement. The net energy for maitenance in the case of high producing dairy cows (~40kg of milk/day) would not cover the total energy requirements of the animals given that the lactation cannot be promptly stopped in case the pathology is present during the lactation. If only the NEm is supplied via the diet, the overall health status of a lactating cow could be worsened. 
6. line 428 - please add reference

7. line 447-458 - What is the basis of these suggestions? please detail. Once again, I highlight the need of a systematic review with more quantitative data in compromised ruminants in order to help determine nutritional suggestions.

8. lines 468 - 470 - please add reference

9. line 474 - 475 - there are numerous studies addressing the meal size and frequency in ruminants. Just to list a few:
   https://doi.org/10.3168/jds.2020-18199
   https://doi.org/10.3168/jds.2013-7504
   https://doi.org/10.3168/jds.2020-18869
   https://doi.org/10.3390/agriculture11080776

   This chapter could also be considered in a systematic review with more quantitative data.

10. line 589 - use upper-script

Author Response

Reviewer 2:

Comments and Suggestions for Authors

I am concerned that this manuscript does not meet the standard criteria for publication in a highly reputable journal. Please consider the following comments and suggestions: 

1. Figure 1 ==> Step 4 "Pharmaconutrients" is misspelled Thanks for noticing this. Corrected in Figure 1.
2. Chapter 3 ==> reccomending to perform a systematic review with more quantitative data on nutrient utilization in compromised ruminants, detailing the animal type (small/big ruminant), growth/production phase, pathology/negative effect on health and/or production. This would give a more organized overview on the existing studies and information in this area. We agree with the reviewer’s recommendation that a systematic review and meta-analysis would be beneficial. Unfortunately, this could not be carried for this paper, as a systematic review and meta-analysis takes over a year and requires at least 5 papers that have the same outcomes and same methodology and there is a lack of sufficient literature to carry out this activity. A systematic review of this area (and meta-analysis) would be a completely separate (and a significant) paper. However, the lack of suitable literature would make this task only suitable for a scoping review.
3. Line 366 - review the wording. Thanks for noticing this. Corrected (L380-381)
4. Chatpter 4. should also be included in the systematic review, as mentioned for Chapter 3. Unfortunately, the lack of suitable literature for ruminants makes this task impossible.
5. line 423-424 ==> Please reconsider this statement. The net energy for maitenance in the case of high producing dairy cows (~40kg of milk/day) would not cover the total energy requirements of the animals given that the lactation cannot be promptly stopped in case the pathology is present during the lactation. If only the NEm is supplied via the diet, the overall health status of a lactating cow could be worsened. Thanks for noticing this. We have added a sentence: “This guideline should still consider the physiological, productive and reproductive status of the ruminant as discussed in the section above (e.g., a lactating dairy cow should be provided enough to support her lactation).” (L442-444)
6. line 428 - please add reference Thanks for noticing this. We have corrected the text and added suitable references. (L445-447)
7. line 447-458 - What is the basis of these suggestions? please detail. Once again, I highlight the need of a systematic review with more quantitative data in compromised ruminants in order to help determine nutritional suggestions. Thanks for your suggestion. References added (L463). Unfortunately, the lack of suitable literature for ruminants makes the task of systematic review impossible.
8. lines 468 - 470 - please add reference Thanks for noticing this. References added (L486)
9. line 474 - 475 - there are numerous studies addressing the meal size and frequency in ruminants. Just to list a few:
   https://doi.org/10.3168/jds.2020-18199
   https://doi.org/10.3168/jds.2013-7504
   https://doi.org/10.3168/jds.2020-18869
   https://doi.org/10.3390/agriculture11080776

This chapter could also be considered in a systematic review with more quantitative data. Thanks for the suggestion. Reading the comment, we realized that we are missing the element of ‘compromised’ in the sentence. Now corrected (L490-493). We agree that for healthy ruminants, this may be an area of interest for a systematic review and meta-analysis. This would be of interest for production. This would make a suitable, separate, manuscript.

1. line 589 - use upper-script. Thanks for this observation. Corrected (L613-614). We have also adjusted the font size in the Table.

Reviewer 3 Report

Comments and Suggestions for Authors

1. Please indicate the source of Figure 1.
2. Line 457-458: What is the basis for the author's suggestion of nutritional adjustment?
3. Section 5.3 does not provide specific cases (such as tetracycline chelation with calcium, feeding adjustments for patients with ulcers caused by NSAIDs). It is suggested to prepare a list summarizing the interactions between common drugs for ruminants and nutrients, as well as the management plans.
4. Line 553, maybe Table 3?
5. Line 612, What does this mean? “{Hall[97]owell, 20[60]16 #65}”
6. Line 704, maybe table 4?
7. Table 5 should be appropriately adjusted by swapping rows and columns. This might make it more aesthetically pleasing.
8. The paper lacks some cutting-edge aspects, such as the neglect of emerging fields like nutrigenomics (such as metabolomics guiding individualized nutrition) and intelligent feeding equipment. It is suggested to add a chapter on "Future Directions" to discuss the application of precision nutrition, real-time monitoring technology and big data in clinical nutrition.

Author Response

Reviewer 3:

Comments and Suggestions for Authors

1. Please indicate the source of Figure 1. This figure is original work of the authors and is not based on a single resource.
2. Line 457-458: What is the basis for the author's suggestion of nutritional adjustment? Thanks for this suggestion. References now included (L463).
3. Section 5.3 does not provide specific cases (such as tetracycline chelation with calcium, feeding adjustments for patients with ulcers caused by NSAIDs). It is suggested to prepare a list summarizing the interactions between common drugs for ruminants and nutrients, as well as the management plans. Thanks for this suggestion. Text adjusted and references now included. “Additionally, absorption of medications/nutrients/supplements may be affected (e.g., ionophores may increase the risk of copper toxicosis, particularly in sheep; tetracyclines may be chelated with calcium or high crude protein, decreasing their orally administered absorption) [95,96]. The interaction may be even more evident under conditions of compromised gut integrity (e.g., requirements to adjust nutritional management in ruminants with ulcers associated with the prolonged use of non-steroidal anti-inflammatory drugs; use of any oral antimicrobials on the rumen microbes in any rumen dysbiosis) [97,98].” (L513-520)
4. Line 553, maybe Table 3? Thanks for noticing this. Corrected (L577)
5. Line 612, What does this mean? “{Hall[97]owell, 20[60]16 #65}”We are sorry, that EndNote mistake has not been spotted. Now corrected (L636).
6. Line 704, maybe table 4? Thanks for noticing this. Corrected (L728).
7. Table 5 should be appropriately adjusted by swapping rows and columns. This might make it more aesthetically pleasing. Thanks for the suggestion but transposing the text made the Table very cluttered and we decided to keep the original format.
8. The paper lacks some cutting-edge aspects, such as the neglect of emerging fields like nutrigenomics (such as metabolomics guiding individualized nutrition) and intelligent feeding equipment. It is suggested to add a chapter on "Future Directions" to discuss the application of precision nutrition, real-time monitoring technology and big data in clinical nutrition. Thanks for the suggestion. A short subheading “Future directions” added as follows:

“Ruminant management and nutrition will become progressively more affected by transformative approaches, including big data, real-time monitoring, precision technologies, and tailored, individualized feeding. Precision nutrition aims to tailor diets to meet the specific nutritional requirements of livestock, based on their production and reproductive status, as well as the stage of the productive cycle, all while considering environmental conditions and health. Precision nutrition, facilitated by intelligent feeding systems, has a two-fold potential, satisfying tailored nutritional requirements by livestock and, by reducing nutritional waste, decreasing environmental pollution. Additionally, it reduces cost, labor requirements, and risk of human-related mistakes [149].

As the understanding of pathophysiology and epidemiology of nutritional disorders increases (e.g., incorporation of metabolomics and nutrigenomics in diagnostics [150,151]), the role of precision nutrition is likely to become more important in clinical nutrition, both in prevention and treatment. Yet, due to the current cost and time delays in obtaining results, the widespread use of precision nutrition, or heavily tailored clinical nutrition in ruminants, is not yet practical.” (L838-853)

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

This second draft of the manuscript presents major improvements and aligns with the requirements of being published in this journal.