Bioconversion in Ryegrass-Fescue Hay by Pleurotus ostreatus to Increase Their Nutritional Value for Ruminant

Round 1

Reviewer 1 Report

This paper presents the results of bioconversion of ryegrass-fescue hay by solid state fermentation. The results give an interesting insight in ability of selected Pleurotus ostreatus strain to convert  nutrients of hay and increase nutritive quality and energy of forage. The layout of the paper is sufficiently good.  The methodology is clear and detailed and results are presented in manner so that potential readers can clearly follow the given discussion. The English is sufficiently good and some small corrections are needed:

Line 56: …which degrades. What? Please complete the sentence.

Line 88: Please add It before HAS at the beginning of the sentence.

Author Response

We appreciate the comments and suggestions indicated.

Line 56: …which degrades. What? Please complete the sentence.

In consideration of the reviewer's suggestion the following text has been added “lignin and opens phenyl rings”

• Line 88: Please add It before HAS at the beginning of the sentence.

We inform you that the correction has been made

Reviewer 2 Report

The aim of the study was to evaluate the bioconservation of hay of ryegrass-fescue by solid state fermentation with Pleurotus ostreatus. The number of samples in the experiment is sufficient. The test methods used are correct. The discussion is well carried out and exhausting. References well chosen.  The list of proposed changes is given below:

                                                         

 

General comments:

Please prepare the article according to the instructions for the authors.

 

For significance description please use lowercase "p" in italic, spaces before and after “<” for example (p < 0.05)

 

When citing reference in the text, there should be no spaces between numbers, for example L50 [6,9,10] instead of current form. This note applies to the entire article.

 

In the References chapter, abbreviated name journal must be used. Year must be in bold, abbreviated name journal and volume number in italic

 

For a page range use a long "-" from the insert function for all References items

 

 

The article lacks the required chapters: Institutional Review Board Statement, Informed Consent Statement, Data Availably Statement.

 

Detailed comments:

L16 5.16% instead of 5.15%

L18 2.82%, no spaces after the number

L95 [19-21] instead of current form

L129 At the end of the Introduction chapter, light research must be given. I propose to define it clearly: "The aim of the research was ... .."

L275 the highest? or higher

L286,288 and others (p < 0.05) instead of current form

L360 [35,46,52], must be left square margin

L513 Asian-Australas. J. Anim. Sci. instead of current form

L573 J. Sci. Food Agric., add dots where needed

 

Author Response

We appreciate the comments and suggestions indicated. The changes made are shown in the manuscript in "yellow"

For significance description please use lowercase "p" in italic, spaces before and after “<” for example (p < 0.05). We inform that the correction has been made

When citing reference in the text, there should be no spaces between numbers, for example L50 [6,9,10] instead of current form. This note applies to the entire article. We inform that the correction has been made

In the References chapter, abbreviated name journal must be used. Year must be in bold, abbreviated name journal and volume number in italic. We inform that the correction has been made

For a page range use a long "-" from the insert function for all References items. We inform that the correction has been made

The article lacks the required chapters: Institutional Review Board Statement, Informed Consent Statement, Data Availably Statement. We inform that the correction has been made.

Detailed comments:

L16 5.16% instead of 5.15%. We inform you that the correction has been made

L18 2.82%, no spaces after the number. We inform you that the correction has been made

L95 [19-21] instead of current form. We inform you that the correction has been made

L129 At the end of the Introduction chapter, light research must be given. I propose to define it clearly: "The aim of the research was ... ..". We inform that the correction has been made

L275 the highest? or higher. We inform you that the correction has been made

L286,288 and others (p < 0.05) instead of current form. We inform that the correction has been made.

L360 [35,46,52], must be left square margin. We inform you that the correction has been made

L513 Asian-Australas. J. Anim. Sci. instead of the current form. We inform you that the correction has been made

L573 J. Sci. Food Agric., add dots where needed. We inform you that the correction has been made

Reviewer 3 Report

Bioconversion in ryegrass-fescue hay by Pleurotus ostreatus to 2 increase their nutritional value for ruminant.

An interesting work that represents an alternative to improve forage quality.

There  are some methodological aspects which need to be clarified (see attached file).

Also, there are some aspects in the discussion which need to be revised (see attached file)

An additional suggestion is related with the practical aspect of SSF. I suggest authors discuss how farmers can use this technique on farms. Fungi cultivation as reported in this research required milling hay with a 2 mm screen, then autoclaving to sterilize it (as done usually in fungi cultivation). This methodology can be cumbersome and not easy to implement in farms.

What would be the strategy to transfer this technology?

 

I believe most of the comments and recommendations (in the file) can be easily answered by the authors

 

Comments for author File: Comments.pdf

Author Response

We appreciate the comments and suggestions indicated. The changes made are shown in the manuscript in "yellow".

An additional suggestion is related with the practical aspect of SSF. I suggest authors discuss how farmers can use this technique on farms. Fungi cultivation as reported in this research required milling hay with a 2 mm screen, then autoclaving to sterilize it (as done usually in fungi cultivation). This methodology can be cumbersome and not easy to implement in farms.What would be the strategy to transfer this technology? I believe most of the comments and recommendations (in the file) can be easily answered by the authors

In consideration of the reviewer's suggestion the following text has been added:

“4.4. Producer-level applications. The Agricultural Research Institute (INIA) of Chile presented a bulletin on the production of oyster mushroom (Pleurotus ostreatus) for human consumption [59]. This is aimed at small and medium-sized agricultural producers, since in INIA's opinion; this is a low-investment crop and is easier to grow than other mushrooms. The authors propose as a means of field pasteurization the immersion of vegetable material in boiling water for a few minutes and incubation in bags. This methodology could be suitable for the objectives of our research, with 14-day incubations, in the dark, to improve lignolytic substrates for animal consumption, but for small volumes of initial vegetable material. An alternative for scaling up the production of plant material fermented by P. ostreatus would be the use of cereal grains inoculated with the fungus, as an additive to pasture hay (or other product intended for animal consumption high in lignocellulose), for storage in silage. Under these conditions, the lignolytic activity of the mycelium would act on the ensiled material, as long as oxygen remains available in the silage, improving the nutritional quality of the final product to be consumed by ruminants. This possible form of production opens new lines of research to study the interactions between the mycelium of the fungus and the bacteria of the ensiled material, the duration of the ensiled material, animal consumption tests and animal performance tests.”

 

Pdf comments

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L154 It is recommended to later include in the discussion the practical aspects to perform SSF.  farmers would certainly not be keen to mill hay with a 2 mm screen and the sterilize the hay (alternatives to autoclaving?.   

In consideration of the reviewer's suggestion the following text has been added:

“4.4. Producer-level applications. The Agricultural Research Institute (INIA) of Chile presented a bulletin on the production of oyster mushroom (Pleurotus ostreatus) for human consumption [59]. This is aimed at small and medium-sized agricultural producers, since in INIA's opinion; this is a low-investment crop and is easier to grow than other mushrooms. The authors propose as a means of field pasteurization the immersion of vegetable material in boiling water for a few minutes and incubation in bags. This methodology could be suitable for the objectives of our research, with 14-day incubations, in the dark, to improve lignolytic substrates for animal consumption, but for small volumes of initial vegetable material. An alternative for scaling up the production of plant material fermented by P. ostreatus would be the use of cereal grains inoculated with the fungus, as an additive to pasture hay (or other product intended for animal consumption high in lignocellulose), for storage in silage. Under these conditions, the lignolytic activity of the mycelium would act on the ensiled material, as long as oxygen remains available in the silage, improving the nutritional quality of the final product to be consumed by ruminants. This possible form of production opens new lines of research to study the interactions between the mycelium of the fungus and the bacteria of the ensiled material, the duration of the ensiled material, animal consumption tests, and animal performance tests.”

 

L214.   In consideration of the reviewer's suggestion the following text has been added:

“A sample composed of hay (consisting of 3 subsamples)”

• We inform that the correction has been made
• In consideration of the reviewer's suggestion the following text has been added:

“Hay samples before and after 14 days of fermentation were taken and dried in a drying oven (model UNB 500, memmet GmbH+Co.KG, Schwabach, Germany) (50°C) until constant weight, to observe microscopic structural changes”

• In consideration of the reviewer's suggestion the following text has been added: “This situation could be due to a late cutting moment, in relation to state of maturation of the pasture.”
• The reviewer makes a comment rather than a change request
• In consideration of the reviewer's suggestion the following text has been added:“The variation in enzyme activity at 21 days of fermentation, specifically in LiP and Lac, can be attributed to the fact that the fungus preferentially degrades lignin and only once this substrate is exhausted, it starts producing enzymes for cellulose and hemicellulose degradation.”

Reviewer 4 Report

The paper aimed to improve the nutritive value of forages which is one of the main goal for the future animal feeding in terms of both economic and environmental sustainability. The authors used adequate methodologies and well depicted their reults. In my opinion the paper needs only few corrections as follows:

line 98: please translate the word "la"

table 1: I understand the values of chemical composion are reported in % as fed, not % of dry matter. It  is true? please  sepcify in the legend.

Table 1: what about the significance of CP, NFC and NDF  modifications after the treatment? Reporting these data could improve the discussion.

Author Response

We appreciate the comments and suggestions indicated. The changes made are shown in the manuscript in yellow.

 

• line 98: please translate the word "la". We inform that the correction has been made
• Table 1: I understand the values of chemical composion are reported in % as fed, not % of dry matter. It is true? please  sepcify in the legend.

In consideration of the reviewer's suggestion the following text has been added: "Except the dry matter value, the nutrient values are reported on a dry matter basis"

• Table 1: what about the significance of CP, NFC and NDF modifications after the treatment? Reporting these data could improve the discussion.

The variations in the nutrient fractions of hay before and after solid fermentation were not analyzed by ANOVA, but through descriptive statistics. For this reason, the significances are not indicated.