The Minimum Dietary Level and Mix Ratio of Krill Meal and Fish Meal to Elicit Feed Intake and Growth Performance in Juvenile Penaeus vannamei

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Your manuscript generates important information that can improve the sustainability of an important resource such as the white shrimp. I thought it is well written, and I believe it should be considered for publication. However, minor corrections are required:

1. Corrections in the abstract, a scientific name is not in italics, and many superindex are missing in measurement units.

2. In M&M sections, there are a couple of proccess where it is necessary to indicate which instrument (and the brand) was used.

3. Indicate the name of the facility in which the experimental diets were formulated.

4. Complete the equation of the Protein deposition formula used.

5. Eliminate the section 3.2. and include Figures and Tables in the section 3.1. after first mention. In the section 3.1, only Fig. 2 and Table 4 are referenced, but the results described in the redaction are included in items Fig. 1, Tables 1-3, please reference them in the text.

6. Some minor changes in redaction indicated in the attached file.

Congrantulations for your work!

 

Comments for author File: Comments.pdf

Author Response

Thank you for your invaluable contributions to revising our scientific manuscript. Your insightful feedback and meticulous attention to detail have significantly strengthened the clarity and quality of our work.

REVIEWER 1:

Comments and Suggestions for Authors

Your manuscript generates important information that can improve the sustainability of an important resource such as the white shrimp. I thought it is well written, and I believe it should be considered for publication. However, minor corrections are required:

 

R1.Q1. Corrections in the abstract, a scientific name is not in italics, and many superindex are missing in measurement units.

R1.A1. Corrected as indicated.

 

R1.Q2. In M&M sections, there are a couple of proccess where it is necessary to indicate which instrument (and the brand) was used.

R1.A2. We have added the model and manufacturer name for the pelleting machine, Y mixer and electronic balance used in the study. Omitting specific brand names or models of water quality equipment is justified by their widespread availability and recognition within the aquaculture industry, ensuring that the text remains concise and focused.

 

R1.Q3. Indicate the name of the facility in which the experimental diets were formulated.

R1.A3. This information was included.

 

R1.Q4. Complete the equation of the Protein deposition formula used.

R1.A4. Corrected

 

R1.Q5. Eliminate the section 3.2. and include Figures and Tables in the section

3.1. after first mention. In the section 3.1, only Fig. 2 and Table 4 are referenced, but the results described in the redaction are included in items Fig. 1, Tables 1-3, please reference them in the text.

R1.A5. Tables and figures were moved to the correct position in the text. They are now correctly referenced along the text.

 

R1.Q6. Some minor changes in redaction indicated in the attached file.

R1.A6. Each point raised in the file was individually addressed in the revised manuscript.

 

Reviewer 2 Report

Comments and Suggestions for Authors

L 2-4 : The paper is about optimisation of KRM and FML and this should be indicated in title or keywords.

L 17-21 : I suggest to place the emphasis on protein content of the shrimp as it is the most critical resource.

L 23 : Scientific name in italic.

L42-44 : I suggest to indicate that lower trophic level aquaculture (seaweed, shellfish, shrimp) are more sustainable compared to higher trophic levels aquaculture (fish).

L 53-56 : Indicate what is the proportion of feed cost among the production cost (energy, labour…)

L 65 : Palatability is more appropriate than chemoattraction in this context.

L 79 : Reference needed.

L 103 : Experimental is more suited than practical. Were the experimental diets performed in duplicates or triplicates ?

L 117 : Indicate the optimal growth temperature for P. vannamei.

L 145-146 : The n = 4,761 is superfluous.

L 156 : Same comment as 103.

L 228 : Mention here the method used for growth phase from 2.7 mg to 1.28 g.

L 306 : Were the datasets normally distributed ? What was the normality test employed ?

L 329 : Indicate for which group(s) the final BW exceeded 10 g.

L 352 : Scientific name in italic.

L 365 : The gross energy (MJ.kg^-1) varies from 16.2 to 17.4 among the experimental diets. Is this taken in account while comparing growth performance ?

L 497-498 : Would it be possible here to speculate about how much the price of shrimp feed will decrease due to the lower inclusion of KRM and FML ?

Comments on the Quality of English Language

The quality of English is sufficient for publication.

Author Response

Thank you for your invaluable contributions to revising our scientific manuscript. Your insightful feedback and meticulous attention to detail have significantly strengthened the clarity and quality of our work.

REVIEWER 2:

R2.Q1. L 2-4: The paper is about optimisation of KRM and FML and this should be indicated in title or keywords.

R2.A1. The word “optimization” was included as a keyword.

 

R2.Q2. L 17-21: I suggest to place the emphasis on protein content of the shrimp as it is the most critical resource.

R2.A2. The abstract was changed accordingly.

“Shrimp aquaculture has been identified as a key part of the solution for food security in the future. As the food need increases globally, production of nutritious food from both land and oceans will be crucial. Farmed shrimp is one of the key species that can deliver food to a growing population, and identifying the most sustainable use of critical marine resources in shrimp feed is an important part of growing the shrimp aquaculture industry. Shrimp feeds depend on high levels of digestible protein, and essential amino acids which can be sourced from various commercially-available feed ingredients. Marine proteins obtained from fish, squid, krill, and other crustaceans can be used to partially fulfill the requirements of these and other important nutrients. However, marine ingredients can significantly drive costs in feed formulation depending on the type and dietary inclusion level.....”

 

R2.Q3. L 23: Scientific name in italic.

R2.A3. Corrected.

 

R2.Q4. L42-44: I suggest to indicate that lower trophic level aquaculture (seaweed, shellfish, shrimp) are more sustainable compared to higher trophic levels aquaculture (fish).

R2.A4. Changed.

 

R2.Q5. L 53-56: Indicate what is the proportion of feed cost among the production cost (energy, labour…)

R2.A5. Added.

 

R2.Q6. L 65: Palatability is more appropriate than chemoattraction in this context.

R2.A6. Chemoattraction refers to the animal's reaction to the food source (including detection, search, movement, and identification), while palatability influences feed intake. Hence, these terms have distinct meanings. Consequently, within the context of the sentence provided, "chemoattraction" seems more fitting than "palatability".

 

R2.Q7. L 79: Reference needed.

R2.A7. Sentence was deleted.

 

R2.Q8. L 103: Experimental is more suited than practical. Were the experimental diets performed in duplicates or triplicates?

R2.A8. In this context, “practical” means diets were made with feed ingredients commonly used by the industry. In the following section, the number of replicate tanks was added.

 

“Shrimp were raised in 70 independent round tanks of 1.0 m3 (h = 0.84 m, d = 1.06 m, bottom A = 0.89 m²), allowing seven replicate tanks per dietary treatment.”

 

R2.Q9. L 117: Indicate the optimal growth temperature for P. vannamei.

R2.A9. Added.

 

R2.Q10. L 145-146: The n = 4,761 is superfluous.

R2.A10. Deleted.

 

R2.Q11. L 156: Same comment as 103.

R2.A11. Deleted.

 

R2.Q12. L 228: Mention here the method used for growth phase from 2.7 mg to 1.28 g.

R2.A12. The following sentence was added “PLs were nursery-reared in five 23-m³ tanks with a commercial crumbled diet containing a minimum of 40% CP.”

 

R2.Q13. L 306: Were the datasets normally distributed? What was the normality test employed?

R2.A13. The following sentences were added “Homogeneity of variance was examined for all data by using Bartlett-Box F and Cochran’s C tests. Kurtosis and skewness and their standard error (i.e., s.e. kurtosis and s.e. skewness) were applied to the data as measures of asymmetry and tests of normality. When needed, data were transformed to a log(x) scale to normalize and homogenize the variances and to meet statistical assumptions.”

 

R2.Q14. L 329: Indicate for which group(s) the final BW exceeded 10 g.

R2.A14. Corrected “The final shrimp BW exceeded 10 g for all dietary groups, except for shrimp fed the 30-30 diet.”

 

R2.Q15. L 352: Scientific name in italic.

R2.A15. Corrected.

 

R2.Q16. L 365: The gross energy (MJ.kg-1) varies from 16.2 to 17.4 among the experimental diets. Is this taken in account while comparing growth performance?

R2.A16. No, we have not discussed on the effect of gross energy as differences among diets were insignificant (CV = 1.8%, 16.9 ± 0.3 MJ kg^-1, mean ± sd).

 

R2.Q17. L 497-498: Would it be possible here to speculate about how much the price of shrimp feed will decrease due to the lower inclusion of KRM and FML?

R2.A17. While krill meal prices are relatively consistent, market prices for fishmeal and other commodity protein ingredients are highly volatile as they are sensitive to several factors. For instance, the supply of fishmeal can be influenced by events like El Niño, leading to reductions in fisheries quotas and driving up market prices. Additionally, shrimp feed formulas, in terms of ingredients, nutrients, digestibility, change significantly from one region to the other. Hence, speculating about potential reductions in feed costs resulting from the use of krill meal instead of fishmeal would be highly speculative and might not be worthwhile.

Reviewer 3 Report

Comments and Suggestions for Authors

The article “Minimum dietary level and mix ratio of krill meal and fish meal to elicit feed intake and growth performance in juvenile Penaeus vannamei,” submitted for publication, is an excellent manuscript with interesting findings; however, it needs revision before acceptance.

 

Several studies about juvenile Penaeus vannamei have been conducted, some of which the authors have mentioned in the discussion. How is the present study different from the other studies? What key differences do the authors aim to address?

Data regarding physical attributes, such as body weight and production statistics about juvenile Penaeus vannamei, should be added to give a clearer picture of the study's importance.  

Line 61. There is mention of “Shrimp.” Is this juvenile Penaeus vannamei or any other kind of shrimp?

Lines 77-79. Which marine sources have been used?

 

Line 81. Which kinds of chemoattractants and palatability enhancers?

 

The text should comprehensively describe the results from Table 3 and Table 4 and present the logic behind important findings.

 

Statistical symbols should be added, where ever necessary, in the tables to present the statistical significance.

 

Lines 452 -456. The authors mentioned the immune parameters from a previous study, but those parameters were not studied. How are such parameters related to the present study when there is no data to compare?

Lines 468-469. Which low molecular weight compounds are present that act as a chemical driver?

All the scientific terms need revision and must be italicized properly. 

The text should be thoroughly revised for its format and syntax. 

Comments on the Quality of English Language

The language and grammar need revision. 

Author Response

Thank you for your invaluable contributions to revising our scientific manuscript. Your insightful feedback and meticulous attention to detail have significantly strengthened the clarity and quality of our work.

REVIEWER 3:

The article “Minimum dietary level and mix ratio of krill meal and fish meal to elicit feed intake and growth performance in juvenile Penaeus vannamei,” submitted for publication, is an excellent manuscript with interesting findings; however, it needs revision before acceptance.

 

R3.Q1. Several studies about juvenile Penaeus vannamei have been conducted, some of which the authors have mentioned in the discussion. How is the present study different from the other studies? What key differences do the authors aim to address?

R3.A1. None of the published studies with krill meal has addressed the potential sparing effect of marine proteins when combining of krill meal and fishmeal. This was emphasized in the last paragraph of the introduction. “Hence, it is crucial to investigate whether these interactions exist among protein ingredients used in practical shrimp feeds, particularly those derived from marine sources, to identify opportunities for reducing their usage for sustainability concerns and to enhance economic results.”

 

R3.Q2. Data regarding physical attributes, such as body weight and production statistics about juvenile Penaeus vannamei, should be added to give a clearer picture of the study's importance.  

R3.A2. The following change was carried out in the introduction “Global production of farm-raised whiteleg shrimp, Penaeus vannamei, has significantly increased in recent years reaching 5.8 million MT in 2020 [1].

 

R3.Q3. Line 61. There is mention of “Shrimp.” Is this juvenile Penaeus vannamei or any other kind of shrimp?

R3.A3. "Shrimp" can refer to various species, including but not limited to Penaeus vannamei (whiteleg shrimp), Penaeus monodon (tiger shrimp, and Penaeus japonicus (Kuruma shrimp), or other commercially important shrimp species.

 

R3.Q4. Lines 77-79. Which marine sources have been used?

R3.A4. This sentence was deleted.

 

R3.Q5. Line 81. Which kinds of chemoattractants and palatability enhancers?

R3.A5. The following text was added “Chemoattractants and palatability enhancers, collectively referred to as feeding effectors (meals and hydrolysates made from krill, squid, and fish), are…

 

R3.Q6. The text should comprehensively describe the results from Table 3 and Table 4 and present the logic behind important findings.

R3.A6. We have carried a throughout discussion of these results in the discussion section. The text thoroughly explained the results from Tables 3 and 4, providing insights into why certain findings occurred. Specifically, it showed that combining precise levels of FML and KRM in shrimp diets can enhance growth performance effectively, even at lower doses than traditionally used. This suggests potential cost savings and sustainability benefits for the industry. However, further research is needed to better understand the optimal dosage of feeding stimulants based on their chemical drivers.

 

R3.Q7. Statistical symbols should be added, where ever necessary, in the tables to present the statistical significance.

R3.A7. Tables 2 and 3 does not contain statistical results as there were no replicate chemical analyses for the experimental diets. Table 4 contains the results from Two-Way ANOVA.

 

R3.Q8. Lines 452 -456. The authors mentioned the immune parameters from a previous study, but those parameters were not studied. How are such parameters related to the present study when there is no data to compare?

R3.A8. The following sentence was deleted “Authors also observed that shrimp fed diets containing 120 g kg^-1 FML and 60 g kg^-1 KRM showed a higher up-regulation of immune parameters, such as prophenoloxidase-activating enzyme, serine protease, and superoxide dismutase.”

 

R3.Q9. Lines 468-469. Which low molecular weight compounds are present that act as a chemical driver?

R3.A9. Sentence was changed to “This is likely because the amount of stimulatory compounds (free amino acids, nucleo-tides, peptides) diverges widely among ingredients.”

 

R3.Q10. All the scientific terms need revision and must be italicized properly. 

R3.A10. Corrected.

 

R3.Q11. The text should be thoroughly revised for its format and syntax. 

R3.A11. Corrected.

 

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have significantly improved the manuscript, which could be accepted after improving the minor errors.