Shredlage Processing Affects the Digestibility of Maize Silage

Round 1

Reviewer 1 Report

This study focused on the effect of conventional and shredlage processing on quality and digestibility of maize silage. The outcome of this research work is of great practical value and is a reference for maize silage. But there are still some questions to answer.

 

 

2.1 Experimental material

The experimental details are inadequate and there is no information on the number of replicates and experimental design.

 

2.2 Chemical analyses

What is the time and temperature of sample preparation based on? Constant weight or some references？

 

Table 2 4.0 mm why not letters between treatments？

 

 

4 Discussion 4.1 …… the first should be avoided, it is a part of the results.

 

Authors need to emphasize the novel insights obtained from this study and to improve.

 

Coclusion need to be highly generalized and should revised by definite conclusion sentence.

Comments for author File: Comments.docx

Author Response

 

 

Response to review of the paper entitled: „The effect of maize forage processing on particle size and digestibility of silage“

 

Dear reviewer,

Thank you very much for your inspiring suggestions. We accepted all of them and tried to incorporate them into the text. Because we added and deleted some references, we changed their numbering.

Kind Regards

Authors

 

 

This study focused on the effect of conventional and shredlage processing on quality and digestibility of maize silage. The outcome of this research work is of great practical value and is a reference for maize silage. But there are still some questions to answer.

 

Comment 1:

2.1 Experimental material

The experimental details are inadequate and there is no information on the number of replicates and experimental design.

 

Response 1:

Harvest was done in practice conditions. Maize was not grown directly for experiment. We made experimental silos during the harvest of silage on the farm. We made one experimental silo per treatment (conventional processing and shredlage processing) in each year. We specified it to the article. (L79 and L 87 to 88)

 

Comment 2:

2.2 Chemical analyses

What is the time and temperature of sample preparation based on? Constant weight or some references？

 

Reponse 2:

The most often method for sample preparation is drying at 60 °C for 48 hours. However, we studied the effect of drying method on chemical composition and digestibility and we found that drying at 50 °C for 48 hours is the best method (except freeze drying, which is very time consuming and expensive) for saving all nutrients and properties of samples the nearest to fresh state.

We inserted reference to the article:

Jančík, F.; Kubelková, P.; Kubát, V.; Koukolová, M.; Homolka, P. Effects of drying procedures on chemical composition and nutritive value of alfalfa forage. S. African J. Anim. Sci. 2017, 47, 96-101. https://doi.org/10.4314/sajas.v47i1.14 (L97 and L340)

 

Comment 3:

Table 2 4.0 mm why not letters between treatments？

 

Response 3:

I am sorry it was our mistake. We supplemented it. We had all letters in this Table badly written (mistakes during making of table). We corrected it. Thanks to reviewer for this notice.

 

Comment 4:

4 Discussion 4.1 …… the first should be avoided, it is a part of the results.

 

Response 4:

We agree with reviewer and we deleted first sentence. (L223 to 225)

 

 

Comment 5:

Authors need to emphasize the novel insights obtained from this study and to improve.

 

Response 5:

We emphasized new knowledge to the text and conclusion.  (L245 to 247, L263 to 265, L286 to 290)

 

Comment 6:

Conclusion need to be highly generalized and should revised by definite conclusion sentence.

 

 

Response 6:

We corrected conclusion according to reviewer suggestion. (L286 to 290)

 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

The author should continue to refine their theme, because the current manuscript covers multiple topics, which will give readers false expectations.

The most fatal problem of this paper is that the number of replicates of animal trail. The variation of silage test is small, so the small sample test is more extensive.  But the variation in animal trail was relatively large, and three animals didn't tell us anything  

There are a lot of abbreviations in the paper, and LIKE many readers, I hate them.  This is just my suggestion that words that do not appear frequently in the paper, or words that are not the core of the paper, should be presented by using their full names, which will make readers have a better reading experience.

Specific comments:

the description of maize forage processing is way too overgeneralize. The author can just write shredlage processing.

L13-15 what other features does the shredlage processor have besides the fact that the TLOC is longer than the regular harvester? Readers still want to see this information in the abstract, otherwise they may mistakenly think that this study is merely comparing silage lengths .

MDPI journals require p-value, but not P-value

L29-33 The author emphasizes the importance of mowing silage at the right time, which is irrelevant with their topic in this manuscript. 

There are too few descriptions about the current situation and problems of kernel processing in the introduction, which is the subject of this paper and should be introduced in detail.  In addition, how does this shredlage processor improve the problems related to kernel processing? Its mechanical principle should also be introduced.  

From the description in the introduction, it seems that the author expects to find out the performance by increased length of silage corn.

L64 The material of silos should be given. The silage filling density should also be given

L70 Why 50℃ instead of the usual 65℃

L98 you could call them wethers. More importantly, Did the author really only use 6 sheep, so there are only 3 sheep in each group?  It is difficult to assess the feeding effect with such a small number of replicates. 

L101-102 Only silages were given? Dose this satisfy the maintain requirements of energy, protein, vitamin, and microelement?

Dry matter loss in silage is an important indicator, why is it not given ?

L163 Apparent digestibility of total tract

L187 what do you refer to by mentioning processed and unprocessed? It need to be a specific process.

L188-190 If sampling makes such a big difference, then all the results could be sampling errors !

L193-194 Harvest years keep popping up in the manuscript, but they don't seem to be relevant to the author's topic.  There is no relevant support in the text about it.  I think this provides more repetition than is needed in the discussion.

L195-201 The author is just describing an phenomenon. They have to come up with their own hypothesis, compare the evidences, and get to its bone.

 

 

 

 

 

Author Response

Response to review of the paper entitled: „The effect of maize forage processing on particle size and digestibility of silage“

 

Dear reviewer,

Thank you very much for your inspiring suggestions. We accepted all of them and tried to incorporate them into the text. Because we added and deleted some references, we changed their numbering.

Kind Regards

Authors

Comment 1:

The author should continue to refine their theme, because the current manuscript covers multiple topics, which will give readers false expectations.

Response 1:

We tried to improve our article according to comments of all reviewers.

Comment 2:

The most fatal problem of this paper is that the number of replicates of animal trail. The variation of silage test is small, so the small sample test is more extensive.  But the variation in animal trail was relatively large, and three animals didn't tell us anything  

Response 2:

We appologize for this inaccuracy in the methodical part. We used six animals and experiment was done as Latin square design. It means that in each year, we made SHR silage and CON silage. Each silage was fed to three animals in first part of experiment and subsequently, the experiment was repeated and animals, which were in first part fed by SHR, were fed by CON and on the contrary. Each silage was fed to six animals. We repeated this experiment in two years. We corrected it in M&M section.

Comment 3:

There are a lot of abbreviations in the paper, and LIKE many readers, I hate them.  This is just my suggestion that words that do not appear frequently in the paper, or words that are not the core of the paper, should be presented by using their full names, which will make readers have a better reading experience.

Response 3:

We reduced the number of abbreviations in the text. For example: TLOC, CF, OM, PSPS.

 

Specific comments:

Comment 4:

the description of maize forage processing is way too overgeneralize. The author can just write shredlage processing.

L13-15 what other features does the shredlage processor have besides the fact that the TLOC is longer than the regular harvester? Readers still want to see this information in the abstract, otherwise they may mistakenly think that this study is merely comparing silage lengths .

Response 4:

Better description of processors were given to the abstract and method. (L15 to 18, L83 to 85)

Comment 4:

MDPI journals require p-value, but not P-value

Response 4:

We corrected it through manuscript.

Comment 5:

L29-33 The author emphasizes the importance of mowing silage at the right time, which is irrelevant with their topic in this manuscript. 

Response 5:

We deleted this part. (L33 to 36)

Comment 6:

There are too few descriptions about the current situation and problems of kernel processing in the introduction, which is the subject of this paper and should be introduced in detail.  In addition, how does this shredlage processor improve the problems related to kernel processing? Its mechanical principle should also be introduced.  

Response 6:

We inserted the mechanical principles of tested processors to the Introduction. (L55 to 72)

Comment 7:

From the description in the introduction, it seems that the author expects to find out the performance by increased length of silage corn.

Response 7:

There is no enough articles which study shredlage or other processors, namely with study of maize processing on digestibility of nutrients. In previous years, differences in maize harvests for silages were only based on different length of particles. Shorter cutting was preferred. The novel method of shredlage is possibility to use it for longer pieces but using shredlage processor allows longitudinal comminution of stem and grain. We inserted it to the introdiction. (L55 to 72)

Comment 8:

L64 The material of silos should be given. The silage filling density should also be given

Response 8:

We inserted these information to the article. (L88 to 90)

 

Comment 9:

L70 Why 50℃ instead of the usual 65℃

Response 9:

According to Czech norm, it is suggested to dry samples at 60 °C for 48 h. However, we studied the effect of drying method on chemical composition and digestibility and we found that drying at 50 °C for 48 hours is the best method (except freeze drying which is very time consuming and expensive) for saving all nutrients and properties of samples the nearest to fresh state.

We inserted reference to the article:

Jančík, F.; Kubelková, P.; Kubát, V.; Koukolová, M.; Homolka, P. Effects of drying procedures on chemical composition and nutritive value of alfalfa forage. S. African J. Anim. Sci. 2017, 47, 96-101. https://doi.org/10.4314/sajas.v47i1.14

(L97 and L340)

Comment 10:

L98 you could call them wethers. More importantly, Did the author really only use 6 sheep, so there are only 3 sheep in each group?  It is difficult to assess the feeding effect with such a small number of replicates. 

Response 10:

We apologize for this inaccuracy in the methodical part. We used six animals and experiment was done as Latin square design. It means, that in each year, we made SHR silage and CON silage. Each silage was fed to three animals in first part of experiment and subsequently, the experiment was repeated and animals, which were in first part fed by SHR, were fed by CON and on the contrary. Each silage was fed to six animals. We repeated this experiment in two years. We corrected it in M&M section. (L135 to 137)

Description “wethers” was given to the text. (L132)

 

Comment 11:

L101-102 Only silages were given? Dose this satisfy the maintain requirements of energy, protein, vitamin, and microelement?

Response 11:

Of course, it cannot satisfy all requirements and, on the other side, some nutrients are overfeed. But the principle of in vivo digestibility detection is that animals are fed by only tested feed – combination with another feeds cannot give good results for tested feeds.

For our animals, it is not problem, because they have not milk or meat production. They are model animals.

Comment 12:

Dry matter loss in silage is an important indicator, why is it not given ?

Response 12:

The dry matter losses were not aim of our study and the silage dry matter losses were low because the silage dry matter was at optimum. We had no enough data for statistical analyses. However, we have now inserted them into the text. (L171 to 172)

 Comment 13:

L163 Apparent digestibility of total tract

Response 13:

We corrected it. (L201)

Comment 14:

L187 what do you refer to by mentioning processed and unprocessed? It need to be a specific process.

Response 14:

We specified it in the text (L226 to 230)

Comment 15:

L188-190 If sampling makes such a big difference, then all the results could be sampling errors !

Response 15:

Yes it is true. But it is citation of literature which should be mentioned. There can be more effects, however we had differences in DM, EE and CP contents (namely between years) and it has no so big effect on nutrient digestibility and peNDF. We wrote there that bigger differences are between years and this is also reason, why experiments are repeated in different years.

Comment 16:

L193-194 Harvest years keep popping up in the manuscript, but they don't seem to be relevant to the author's topic.  There is no relevant support in the text about it.  I think this provides more repetition than is needed in the discussion.

Response 16:

It is partially true. But we did silages in two years. Year was also given to the statistical model and we think, that it is important mentioned it also in the text.

 

Comment 17:

L195-201 The author is just describing an phenomenon. They have to come up with their own hypothesis, compare the evidences, and get to its bone.

Response 17:

We supplemented this part (L235 to 245)

Author Response File: Author Response.docx

Reviewer 3 Report

The aim of the paper is quite interesting, especially the results of the digestibility trial. Otherwise I am skeptical because only one repetion per treatment (silage) was made, if I understood your description right? And from the two different processed silages you took three samples. That means, you tested only 6 samples per year, 12 in total? This is in my opinion the most weakest point of the study.

A major need for action I see in the "Materials and Methods" part, especially in part 2.2 Chemical analyses. Here are some irregular descriptions of the used methods. Please use well documented methodical descriptions according to international standards. Add the number of the method, for example from AOAC International or from the EU "Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed". Please check this fact for all chemical parameters. Crude fiber is missing in the methods, ether extract is incomplete. ADF and NDF are not correct described, in both cases the content after combustion is cited in the results (Table 1), but in M/M  the description is not adaquate.

line 89-93: the the methods should be listed in the logical order, for example: first pef followed by peNDF

Results:

line 137: the sentence is not correct! Ether extract was different between the years. Be more critical with your own results!

Discussion:

line 196-197: in the cited literature Kung and Shaver I could not find the data written here. Please check your statements and be correct with the designation of the numbers, should it be the pH? I found in the cited lit. : 3.7-4.2 for pH, 4-7 % for acetic acid...

line 198-200: the quote [5] should cited correct as Kononoff et al., but in this quote I could not find your cited data. Please check if this is the right quote.

therefore I could not agree with your statement in line 200-201. I found a high match with the recommendations published by Kung and Shaver.

 

Author Response

Response to review of the paper entitled: „The effect of maize forage processing on particle size and digestibility of silage“

 

Dear reviewer,

Thank you very much for your inspiring suggestions. We accepted all of them and tried to incorporate them into the text. Because we added and deleted some references, we changed their numbering.

Kind Regards

Authors

Comment 1:

The aim of the paper is quite interesting, especially the results of the digestibility trial. Otherwise I am skeptical because only one repetion per treatment (silage) was made, if I understood your description right? And from the two different processed silages you took three samples. That means, you tested only 6 samples per year, 12 in total? This is in my opinion the most weakest point of the study.

Response 1:

Yes it is true, however, we repeated in two years. So in totally there were 2 silages for conventional and 2 shredlage silages. We know that more silages would be better, however in vivo experiments are time consuming and demanding. Preparing of silages was done from practise conditions of farm and we were very happy that we organised harvest by two harwestor from one field in the same time. For in vivo experiments, we used six wethers. This study is primary because we did not find another study with similar experiments.

 

Comment 2:

A major need for action I see in the "Materials and Methods" part, especially in part 2.2 Chemical analyses. Here are some irregular descriptions of the used methods. Please use well documented methodical descriptions according to international standards. Add the number of the method, for example from AOAC International or from the EU "Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed". Please check this fact for all chemical parameters. Crude fiber is missing in the methods, ether extract is incomplete. ADF and NDF are not correct described, in both cases the content after combustion is cited in the results (Table 1), but in M/M  the description is not adaquate.

Response 2:

We corrected all methods and supplemented missing information. Thank you for this notice. (L101 to 110)

Comment 3:

line 89-93: the the methods should be listed in the logical order, for example: first pef followed by peNDF

Response 3:

We corrected text according to reviewer suggestion. (L121 to 122)

Results:

Comment 4:

line 137: the sentence is not correct! Ether extract was different between the years. Be more critical with your own results!

Response 4:

We corrected it and inserted this fact to the text. (L174 to 175)

Discussion:

Comment 5:

line 196-197: in the cited literature Kung and Shaver I could not find the data written here. Please check your statements and be correct with the designation of the numbers, should it be the pH? I found in the cited lit. : 3.7-4.2 for pH, 4-7 % for acetic acid...

Response 5:

I am sorry, it was our mistake, so we corrected it. (L238)

Comment 6:

line 198-200: the quote [5] should cited correct as Kononoff et al., but in this quote I could not find your cited data. Please check if this is the right quote.

Response 6:

I am sorry, it was our mistake, we corrected it. (L239 to 240)

Comment 7:

therefore I could not agree with your statement in line 200-201. I found a high match with the recommendations published by Kung and Shaver.

Response 7:

I am sorry, it was our mistake, we corrected it. (L240 to 245)

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

In general, this manuscript has been improved significantly, especially in the introduction and method parts. However, I do not like this very general and confusing title. Still not sure what the author wants to study after reading this title. There was a lot of emphasis in the discussion on the role of years, and I couldn't easily grasp the role of treatment as I read.  The difference between years is of no interest in this manuscript. 

The description of Latin square design in the method is also strange. The animal has been through 14 days trail, and the Latin square has been made later?  This is the first time I've seen the 6 by 2 Latin square. How many transversals the animals experienced?

What does the interaction of years and treatments show in a Latin square  design?

In line 235 the author mentions that treatment has no effect on fermentation, but in line 246 it says that longer corn material will reduce silage fermentation. This part confuses me.

 

Author Response

Response to review of the paper entitled: „ The effect of shredlage processing on digestibility of maize silage “

 

Dear reviewer,

Thank you very much for your inspiring suggestions. We tried to incorporate them into the text.

Kind Regards

Authors

Comment 1:

In general, this manuscript has been improved significantly, especially in the introduction and method parts. However, I do not like this very general and confusing title. Still not sure what the author wants to study after reading this title.

There was a lot of emphasis in the discussion on the role of years, and I couldn't easily grasp the role of treatment as I read.  The difference between years is of no interest in this manuscript. 

Response 1:

We changed the name of manuscript: „The effect of shredlage processing on digestibility of maize silage. If the reviewer won´t agree with this change, we will request him to help us.

The experiment was repeated over two years. Because it is one of the factor, influenced the experiment, the effect of year (repetition) was necessary to insert to the statistical model and then it was fundamental to introduce in discussion, especially when some differences were found.

Comment 2:

The description of Latin square design in the method is also strange. The animal has been through 14 days trail, and the Latin square has been made later?  This is the first time I've seen the 6 by 2 Latin square. How many transversals the animals experienced?

Response 2:

We consulted it with our colleague, which is specialist on statistical and experimental modelling, and he told us that we have it badly formulated in text and it cannot be described as Latin square but it is factorial design. We are sorry for that.

Our experiment was done as follows:

We had 6 weathers in totally in our experiment. These 6 animals were divided into two groups and one group was fed by CON silage and second by SHR silage for 14 days as preparing period and 5 days as sampling period. The silages were changed between groups and again, they were fed 14 days in preparing period and 5 days in sampling period. This experiment was repeated in two years.

We hope that now it is better explained. We corrected it also in manuscript. (L134 to 139)

Comment 3:

What does the interaction of years and treatments show in a Latin square design?

Response 3:

As we wrote in previous response, it was not Latin square design. We corrected it in the text. Interactions should show us if there are some differences among digestibility of nutrients in treatments and years. In our results, it was only in starch digestibility. (L247 to 250)

 

 

Comment 4:

In line 235 the author mentions that treatment has no effect on fermentation, but in line 246 it says that longer corn material will reduce silage fermentation. This part confuses me.

Response 4:

One of the important parameter of maize processing through the shredlage method is the theoretical length of cut about 20 to 30 mm. It is significantly more than at the classical processing. Some farmers have fears of quality of maize silage processing because the longer chopped material won´t be compact well. We approved in our experiments, that shredlage method didn´t influence quality of fermentation, and therefore it is not necessary to suspect of this. The sentence was adjusted to raise the simplicity.

Author Response File: Author Response.docx