Solid-State Hydrolysis (SSH) Improves the Nutritional Value of Plant Ingredients in the Diet of Mugil cephalus

Round 1

Reviewer 1 Report

The manuscript with ID (fishes-1518638) by Martínez-Antequera and coauthors evaluated the enzymatic pre-treatment of some plant by-products such as brewers’ spent grain and rice bran to improve their nutritional quality for Mugil cephalus. The study is interesting; however, I find Major Revisions to be carefully amended by authors before the manuscript is considered for publication in Fishes. Authors should prepare line-by-line response to the following points.

Line 13: Mugil cephalus

Line 16: “commercial feed for carp” – Did the commercial basal diet for carp can be used for Mugil cephalus? I think the nutritional requirements will differ between both fish species.

Line 26: Add a brief and concise conclusion about the importance of your study.

Line 27: Add keywords that do not present in the title and closely linked to your findings to facilitate the search about your paper.

Line 39: Support with a recently published paper (Aquaculture, 2021, 530, 735738).

Line 55: Support with the recently published review article that focused on the anti-nutritional factors present in plants. Benefits and applications of Moringa oleifera as a plant protein source in Aquafeed: A review. Aquaculture, 2022, 547, 737369

Line 97: “It contains several animals” – This sentence is incorrect – revise to “It contains several byproducts such as

Page 4 of 15:

• Line numbers overlapped the table.
• Revise “Taurine”
• Add the composition of mineral and vitamin premixes, and company provided (Company, city, Country).
• Add GE and NPE values of the EXP diet
• Most experimental diets add methionine and lysine in their basal diets. Explain why you did not add them?

Line 170: Prior to tissue collection, fish were killed by cervical section” – I think you must revise the method of killing fish. Most papers used anesthetic for induction of safe euthanasia. I think the Guidelines of the European Union Council do not contain this method.

Line 182: Hepatosomatic index (HSI)

Lines 218-219: Add the tests used to determine the normality and homoscedasticity of 218 the data.

Line 504: Japanese seabass (not italic)

Line 543-544: Fish Physiology and Biochemistry

Line 577: Oncorhynchus mykiss

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The present study investigated the effect of enzyme pretreatment of highly fibrous plant ingredients by solid-state enzymatic hydrolysis using a commercial multi-enzyme to improve the nutritional quality of a practical diet of grey mullet. The Grey mullet is one of the interesting species which will have a good contribution to aquaculture in the next years especially in the MINA region.

Accordingly developing a practical diet with cost-effective and high feed conversion is a prime of interest. The present manuscript will be interesting for man groups of farmers, feed manufacturers, and scientists. However, the manuscript still needs major revision before being accepted for publication, including a simple economic evaluation.

I addressed the major concern at the bottom of this letter and please consider the attached pdf for all comments.

Suggested title

Solid-state enzymatic hydrolysis improves the nutritional value of plant ingredients in the diet for Mugil cephalus

Abstract

• I suggest to used the term “Solid-state enzymatic hydrolysis” along the manuscript.

L 13: formulated feed instead of feed formulated

Add the common name and the full-length scientific name for the first mention Mugil cephalus.

• The introduction well constructed and written in agood languge, it can be improved by incorporating some new puplushed data regarding formulating practicales diets for grey mullets with alternative sources, such as

https://doi.org/10.3390/fishes6030038

https://doi.org/10.3390/su13137093

https://doi.org/10.3390/jmse9121336

• The Materials and methods

Follow the correction indicated in the attached PDF , along with the following suggestions:

Table 1: Add the proximate composition of the commercial diet in a separate column for easy comparison.

L 162: Daily ration was adapted according to weight controls carried out every 14 days. It the feed were appearent satiation (ad libitum) or with percent of weight . Also, the daily ration could adjusted separtly for each replicates not the control.

Rewrite the different equations with MDPI style considering the suggested correction in the PDF.

In Statistical analysis:

the author compared the 3 diets they used one way ANOVA, but when compared the two EXP diet it could be compared with T-test please revise the statistical analysis.

 

• Results:

Merge table 2 and 3 with adjusting the table caption. (suggested correction in the PDF).

In all tables, consider the abbreviations (including the diet names), units,  statistical note in the footnote.

Divide the results section to subtitle (Growth performance, Blood bioche…….)

The discussion is very long and need to be abbreviated to the half.

Could you add a simple economic evaluation, it could maximize the benefit of your results.

• Conclusions need to support with the obtained results.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have properly addressed the comments in the modified version of the manuscript.

Reviewer 2 Report

However, the authors did not use highlight or track changes to follow their responses in the MS or write line numbers of the modifications in the cover letter (which could be considered in their future works), they substantially improved the MS and responded to all my comments. Accordingly, I recommended the publication of this manuscript.