Growth Performance and Meat Quality of Growing Pigs Fed with Black Soldier Fly (Hermetia illucens) Larvae as Alternative Protein Source

Round 1

Reviewer 1 Report

Revision of Manuscript ID: processes-1842781 Title: Growth performance and Meat quality of Growing pigs Fed with black soldier fly (Hermetia illucens) larvae as alternative protein source In line 23: You have indicated that the T2 (8%) was the best, and at the end of the abstract (line 29) you indicated that using the T1 (4%) as a substitute for protein is considered the best, knowing that there were significant differences in the daily growth rate between the T1 and T2 groups…. please check that.
In line 95 and 96 you said “In the weaning period (day28-day70)” How are animals weaned in such a wide range, please explain.
In line 20 you said that the trail lasted 116 day and in line 110 in M&M you said that the trail lasted 113 day, In line 95 and 96 you said  that the weaning period was day28-day70  and in line 97 you said that the growth stage day70: day 120……. How did you calculate the total period of the experiment, whether 113 days or 116 days? .......... Please, if you can make a map showing the beginning and end of the experiment and the dates of sampling, it would be better.
In line 122 please revise the slaughter date….
In the item of statistical analysis, did you test the normal distribution of the data, and accordingly either one-way analysis of variance or Kruskal-Wallis tests were used... Please explain that…
If the examination of the normal distribution gave a non- significant result you can use One way anova with standard error and the parametric tests such as Duncan or Tukey ....etc… should be used to detect the significant differences between means and this should be illustrated in Statistical analysis item in M&M part.
In general, you should use the standard error in the case of using a one-way analysis of variance, and the use of standard deviation is in the case of using Kruskal-Wallis…. Please revise this in all tables and graphs…..
In line 233 you said that the metabolites of the three dietary treatments were subjected to principal component analysis (PLS-DA)… What is the program used? Please add this part in M&M.
In line 292 and 296 I think moving this part “To replace part of the soybean meal and soybean oil or fish meal, 4% and 8% black soldier fly larvae meal were added” to the M&M part would be better.
In line 327, 328, 329, 330, and 331, the sentence that begins with Myosin and ends with acid needs a reference.
Please review the format of references according to the journal system in all parts of the research...  lines 332, 334, 347, and 354……It is preferable to use the end note in the format of references

Author Response

Thank you very much for your valuable comments and suggestions, we have made the following modifications to the article:

1. Thank you very much for the reminder, we have revised the summary: 'The results of the present study showed that adding 4% black soldier fly instead of fish meal in the diet of growing pigs can significantly improve meat quality and supplementation of 8% black soldier flies has beneficial effects on growth performance of pigs.'.
2. I'm sorry to have troubled you with my inappropriate statement. The growth of piglets is divided into three stages according to their characteristics: lactation period, nursery period and growth and fattening period. The time period is lactation period: birth-28 days, nursery period 28-70 days, growth and fattening period 70-180 days. The 'weaning period' I expressed in the original text is actually the 'nursery period'. In the text I have modified the corresponding position. For the errors in the experimental period I have revised and added the corresponding experimental period map.
3. I very much agree with your suggestion on the data analysis section. Regarding the statistics, I have made the following modifications: According to your suggestion, we performed the Shapiro-Wilk test of the normal distribution on the data and found that the data conformed to the normal distribution. Data were subsequently analyzed for significance using one-way ANOVA and Tukey's post hoc test, with additions and modifications in the Materials and methods section. Since the analysis method used in this experiment is one-way analysis of variance, the data in the pictures and tables are expressed as mean ± standard error.
4. In the "Statistical Analysis" Section, we supplement the content and software used for Partial Least Squares Discriminant Analysis (PLS-DA).
5. Thanks for your suggestion, we have added the sentence 'To replace part of the soybean meal and soybean oil or fish meal, 4% and 8% black soldier fly larvae meal were added. We performed a histological study of backfat and evaluated fat cell density and volume to see if fat cell volume growth causes backfat thickening' in the histology section of Materials and methods.
6. Sorry for the inconvenience caused by the wrong reference format, we have modified the reference format according to your suggestion.

Our research group would like to thank you for your valuable comments and suggestions, which are important to improve our article and guide future research.

 

Reviewer 2 Report

Review

Growth performance and meat quality of growing pigs fed with black soldier fly (Hermetia illucens) larvae as alternative protein source

 

The article is interesting from the point of view of an alternative source of protein in pig nutrition. Similar experiments are carried out on poultry, but in times of crisis caused by the increase in fossil fuel prices, as well as the increased use of a non-genetically modified source of general protein, the use of Hermetia illucens larvae allows for increased flexibility in the preparation of feed mixtures for pigs, as well as limiting the use of vegetable oil in mixtures for animals. Below, a small number of uncertainties to include in revising the manuscript:

Line 16 n=24 in total in three treatments. That could affect for power of a test which could be to low. In this case precision of experiment will be important. And that is why presented sd could have high values in tables. Better is to increase number of animals in replication from 1 to 6-12 (what will increase number of needed animals from 48 to 96 piglets in experiment) then mean value for treatment will be more accurate. But of course it depends from intake of Hermetia illucens by piglets/pigs and  the possibility of obtaining such amount  this kind of component.

Line 41 You need to delete space

Line 61 Space needed before [15]

Line 66 Space needed before [16]

Line 112 Total amount of components must be equal 100%, because even 100.48 decrease concentration of nutrients in kg, in comparison with requirements in norms in this period of life. Recalculation is needed for weaned piglet feed formula. The easiest way is to subtract from corn 0.48, 0.75 and 0.64 respectively for C, T1 and T2. CP and DE in diets must be respectively isoproteic and isoenergetic, but in this case small differences are acceptable between values in treatments/experimental groups (about 20.3 and so on)

Line 185 In tables  only mean and sd are used. It’s no need to use mean±SEM. SEM (standard error of the mean) is calculate as sd from 24 values/square root 24 and this is only one value presented in table something like p-value. Students t-test compare only two groups, perhaps in this place should be used name of post-hoc test Duncan/Tukey, any else to obtain differences between groups (a,b,…).

Line 376 ‘The results showed…’. Maybe better to change for ‘The results showed that adding black soldier flies used to growing pig feed could significantly improve the quality of pork, increase amount of individual amino acids in muscles, and gene expression of slow-twitch muscle fibers.’

Line 393. References needs a little correction. Dots are needed in case of Journal abbreviations i.e. Anim. Nutr.

Line 394. On the end of information about article after pages before doi must be dot (.) instead of comma (,).

Author Response

Thank you very much for your valuable comments and suggestions, we have made the following modifications to the article:

1. I really appreciate your suggestion on the number of replicates in experimental animals, increasing the number of replicates in experimental animals is critical to improve experimental accuracy. In this experiment, due to experimental conditions and some objective factors, we only carried out a small group experiment, and there are certain limitations due to the small number of animals in this experiment. In this experiment, we found that the additive black soldier flies had a tendency to improve pork quality and growth performance to a certain extent. In future large-group experiments, we will increase the number of replicates of experimental animals according to your suggestions to improve the accuracy of the experiment. Thanks again for your opinion.
2. The problem in lines 41, 61 and 66 has been fixed, thank you very much for your suggestion.
3. We have made slight changes to the formula based on your suggestions for the diet formula to ensure equal crude protein and digestible energy while maintaining equal total weight.
4. Based on your suggestion, we have modified the data analysis and table, in the Materials and methods section to: After performing the normal distribution test, the data were analyzed using one-way ANOVA, with tukey post hoc test for significance analysis, due to the one-way ANOVA method is used, and the use of standard deviation is in the case of using Kruskal-Wallis. So the data in the table needs to be expressed as mean ± standard error. 
5. Thank you very much for your suggestion on Line 376 ‘The results showed…’. We have revised this in the article.
6. I'm sorry for the trouble caused by the error of the reference format. I have adjusted the format of the reference in the original text.

Our research group would like to thank you for your valuable comments and suggestions, which are important to improve our article and guide future research.

Round 2

Reviewer 1 Report

Please convert the standard deviation in all the tables to standard error according to the way i have taught you before, as long as you prove the normal distribution of the data.

Author Response

Dear Reviewer:

Thank you very much for your reminder. Due to our negligence, we did not modify the data in the table in time after completing the normal distribution test yesterday. We have re-analyzed the data using one-way ANOVA and revised the data in the manuscript, modifying the data in the table to mean and standard error based on your comments.
Thanks again for your comments, if you have comments or suggestions anywhere else in the manuscript we will revise and respond positively.