Alfalfa Stem Cell Wall Digestibility: Current Knowledge and Future Research Directions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I consider that it is important to also include in this work a review of the use of additives  (fibrolytic enzymes and ferulic acid esterase-producing lactic acid bacteria) for improve alfalfa silage digestibility.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Reviewer 1:

I consider that it is important to also include in this work a review of the use of additives (fibrolytic enzymes and ferulic acid esterase-producing lactic acid bacteria) for improve alfalfa silage digestibility.

Response: We added texts in line 379-389 in the revision related to use of additives for improving alfalfa silage digestibility. We cited references as well.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors, 

It was a pleasure to revise your manuscript entitled "Alfalfa stem cell wall digestibility: current knowledge and future research directions. Your revision is well-structured and covers the essential literature about previous findings and gaps. 

Currently, enteric methane is an important issue, and some studies have shown the importance of digestibility on the potential CH4 production from forages. I suggest the authors write one or two paragraphs regarding cell wall digestibility and CH4 emissions. Could you provide future directions? 

Please see "Enteric methane emission, diet digestibility, and nitrogen excretion from beef heifers fed sainfoin or alfalfa". This study might be helpful. 

I am looking forward to seeing your revised version of this manuscript reviewer. 

Author Response

Reviewer 2:

Comment:

Currently, enteric methane is an important issue, and some studies have shown the importance of digestibility on the potential CH4 production from forages. I suggest the authors write one or two paragraphs regarding cell wall digestibility and CH4 emissions. Could you provide future directions? 

Response: We have added a paragraph in line 146-158 in the revision discussing the relationship between NDF and CH3 emissions.  Also added a future direction in the section.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is well written and easy to read.

The authors have done an excellent job citing papers, including at least 13 papers published in the last 5 years.

A few suggested corrections:

line 60 alfalfa stem digestibility can be affected by several factors...

line 66 should the phase be cell-cell digestibility as listed or cell-wall?

line 66-67 reword to say Researchers have used NIRS-based screening approaches and found...

line 128 were found to rapidly and completely degrade with the first

line 278-279 through altering ADL and in vitro neutral detergent fiber (remove in)

line 337 remove in) suggested that decreased total CW concentration

line 364-367 Gene modification to change the lignin content via breeding, increasing the amount of cellulose without increasing lignin content and increasing rapidly fermentable carbohydrates in alfalfa would be some of the potential future strategies to improve alfalfa digestibility and ruminant utilization.

I don't believe reference 69 by Akin and Rigsby are cited in the manuscript unless you misnumbered in the text.

Reference 66 by Morrison - should be Lolium perenne

Reference 68 by Jung and Fahey - no year given; should be 1983; in Vitro

Reference 93 by Strobel and Russell - in title should be pH not PH

Comments on the Quality of English Language

Quality of English very good, only a few suggestions.

Author Response

Reviewer 3:

The manuscript is well written and easy to read.

The authors have done an excellent job citing papers, including at least 13 papers published in the last 5 years.

A few suggested corrections:

line 60 alfalfa stem digestibility can be affected by several factors... (fixed)

line 66 should the phase be cell-cell digestibility as listed or cell-wall? (fixed)

line 66-67 reword to say Researchers have used NIRS-based screening approaches and found...  (edited)

line 128 were found to rapidly and completely degrade with the first (fixed)

line 278-279 through altering ADL and in vitro neutral detergent fiber (remove in)-(fixed)

line 337 remove in) suggested that decreased total CW concentration (fixed)

line 364-367 Gene modification to change the lignin content via breeding, increasing the amount of cellulose without increasing lignin content and increasing rapidly fermentable carbohydrates in alfalfa would be some of the potential future strategies to improve alfalfa digestibility and ruminant utilization.-(fixed)

I don't believe reference 69 by Akin and Rigsby are cited in the manuscript unless you misnumbered in the text. (fixed- was misnumbered)

Reference 66 by Morrison - should be Lolium perenne  (fixed)

Reference 68 by Jung and Fahey - no year given; should be 1983; in Vitro  (fixed)

Reference 93 by Strobel and Russell - in title should be pH not PH   (fixed)