Effects of Dietary β-Mannanase Supplementation on Egg Quality during Storage

Round 1

Reviewer 1 Report

Lines 24-25: “β-mannanase was able to improve egg weight and 24 albumen weight (P < 0.05) during storage.”. Review this sentence again. In general, egg weight decreases during storage.

Lines 39-40: Add the references for  “conditions of temperature, light, relative humidity, and handling.” please.

Line 40: What effects does light have on storage characteristics?

Lines 47-48: Add the references for  “ improve egg quality and shelf life” please.

Lines 115-116: You can add the following citation since Funk was the one who at first calculated the Yolk index. “Funk, E. 1948. The relation of the yolk index determined in natural position to the yolk index as determined after separating the yolk from the albumen, Poultry Science, 27, (3), 367-367.”

Lines 129-132:  If you calculated the specific gravity according to Archimedes' principle, it should be expressed by the following formula: He used this method for the first time in 1968.

Specific gravity = Egg weight (g)/(Egg weight – Egg weight in water) [Wells R: A study of the hen’s egg. British Egg Marketing Board Symposium, Edinburgh. 207-249, 1968.)

You can check out the article about specific gravity below.  “Sariyel V, Aygun A, Coklar H, Narinc D, Akbulut M: Eff ects of prestorage application of gum arabic coating on the quality of table eggs during storage. Kafk as Univ Vet Fak Derg, 28 (3): 363-370, 2022. DOI: 10.9775/kvfd.2022.27077

Table 1: Why did you use "g" when calculating the egg weight loss? Usually, weight loss is expressed as a percentage.

Line 182: Change "albumen height" to "albumen weight."

Table 2: Why did you measure the weight of the albumen during storage in grams? It would be more precise to measure in percentages. because heavy albumen will result from heavy eggs.

Lines 195-198: A table of these properties is not given.

Lines 210-224: A table of these properties is not given.

Lines 328-330: The "a*" value is the characteristic that most accurately describes egg yolk color. The article below discusses this topic in more detail. “An application of bootstrap technique in animal science: egg yolk color sample, Kafkas Üniversitesi Veteriner Fakültesi Dergisi 21 (5), 631-637”

Lines 295-297: ?

Change "SE" to "SEM" in all tables.

What did you want to refer to as Table S1, Table S2, and Table S3?

Giving the P value as "P<0.05" rather than "P= 0.020" would be more appropriate to maintain the integrity of the article.

 

 

Author Response

Dear, thank you very much for reviewing the paper and for the helpful comments.

Lines 24-25: “β-mannanase was able to improve egg weight and albumen weight (P < 0.05) during storage.”. Review this sentence again. In general, egg weight decreases during storage.

Response: We changed the text to ` β-mannanase was able to prevent the loss of egg weight and albumen weight (P < 0.05) during storage when compared to the control group.` (L24, L25) for a better understanding.

Lines 39-40: Add the references for  “conditions of temperature, light, relative humidity, and handling.” please.

Response: References added as suggested (L42)

Line 40: What effects does light have on storage characteristics?

Response: `light` was withdrawn from the text

Lines 47-48: Add the references for  “improve egg quality and shelf life” please.

Response: Reference added as suggested (L49)

Lines 115-116: You can add the following citation since Funk was the one who at first calculated the Yolk index. “Funk, E. 1948. The relation of the yolk index determined in natural position to the yolk index as determined after separating the yolk from the albumen, Poultry Science, 27, (3), 367-367.”

Response: Reference added as suggested (L115)

Lines 129-132:  If you calculated the specific gravity according to Archimedes' principle, it should be expressed by the following formula: He used this method for the first time in 1968.

Specific gravity = Egg weight (g)/(Egg weight – Egg weight in water) [Wells R: A study of the hen’s egg. British Egg Marketing Board Symposium, Edinburgh. 207-249, 1968.) You can check out the article about specific gravity below.  “Sariyel V, Aygun A, Coklar H, Narinc D, Akbulut M: Effects of prestorage application of gum arabic coating on the quality of table eggs during storage. Kafk as Univ Vet Fak Derg, 28 (3): 363-370, 2022. DOI: 10.9775/kvfd.2022.27077

Response: Thank you for the suggestions; the text was altered and the reference was added.

Table 1: Why did you use "g" when calculating the egg weight loss? Usually, weight loss is expressed as a percentage.

Response: We choose g because there were effects of the treatments on the initial weight and because the data in % used to have a distribution that complicates the use of ANOVA, which was important for this study.

Line 182: Change "albumen height" to "albumen weight."

Response: We believe the correct one is `albumen height` (the table can be found on the supplemental material – table S2)

Table 2: Why did you measure the weight of the albumen during storage in grams? It would be more precise to measure in percentages. because heavy albumen will result from heavy eggs.

Response: We added % in the results (L187-191), but kept g on the table.

Lines 195-198: A table of these properties is not given.

Response: Can be found in table 1

Lines 210-224: A table of these properties is not given.

Response: They can be found in the supplemental material

Lines 328-330: The "a*" value is the characteristic that most accurately describes egg yolk color. The article below discusses this topic in more detail. “An application of bootstrap technique in animal science: egg yolk color sample, Kafkas Üniversitesi Veteriner Fakültesi Dergisi 21 (5), 631-637”

Response: Thank you for your suggestion. The article was added to the discussion (L328-330)

Lines 295-297: ?

Response: They can be found on the supplemental material (Table S5)

Change "SE" to "SEM" in all tables.

Response: Text was altered as suggested

What did you want to refer to as Table S1, Table S2, and Table S3?

Response: Those tables are supplemental material. It was debated among the researchers of the group, that only significant differences between treatment and control groups would be further discussed in the paper, by pointing out the main results, so the article doesn`t get long and confusing. So the results of supplemented tables and those with no significance were not discussed.

Giving the P value as "P<0.05" rather than "P= 0.020" would be more appropriate to maintain the integrity of the article.

Response: Presenting the exact P-value is more informative for the readers, in our opinion. For that reason, the format was maintained for any value between 0.001 and 0.100. Values lower or higher were classified as <0.001 or >0.10.

Reviewer 2 Report

This manuscript evaluated the effects of dietary supplementation with β-mannanase on the quality of storage eggs from laying hens, and found out that the egg weight, albumen weight, yolk color, yolk pH and TBARS of eggs were improved compared to the control. The manuscript has been well organized and the data is sufficient to support the conclusion. However, the following points need to be addressed to improve the overall quality of the manuscript:

1.     It is described in “2 Materials and Methods” that 300 g/ton of β-mannanase was supplemented to the BMA group. Why only one dose of β-mannanase was studied? Did you choose this supplement dose based on previous study or some standards? Do you think that the supplement dose may also have an important impact on egg quality?

2.     In the abstract, author declared that the objective of this study was to evaluate whether dietary supplementation with β-mannanase can improve the quality of storage eggs from laying hens. However, almost all the differences in egg weight, albumen weight, yolk color, yolk pH and TBARS of eggs between control and BMA group occurred since day 0 and did not show regular changes during storage. Moreover, in the conclusion, only the effects of β-mannanase on the quality of eggs were proposed, not the storage quality. Why do you think the dietary supplementation with β-mannanase have some specific effects on the storage quality of eggs?

3.     In order to better study the effect of dietary supplementation with β-mannanase on the the storage quality of eggs, indicators of egg freshness such as Haugh unit and yolk index should be measured.

4.     Although the effects of dietary supplementation with β-mannanase on the quality of storage eggs were discussed, but the mechanism was rarely explored. For example, why dietary supplementation with β-mannanase increased the eggshell weight? Was it to increase the thickness or density? In Line 315-318, author proposed that β-mannanase may facilitate the action of enzymes and increase the amount of protein absorbed. However, the results only show the increase of albumen weight not the protein content in albumen, and the increased weight might also be due to the increase content of water. Therefore, further studies such as the micro-structure of the eggshell, the composition of the albumen and yolk should be carried out to explore the action mechanism of β-mannanase.

5.     Table 9, “Probiotic” should be corrected to “”BMA”.

Author Response

Dear, thank you very much for reviewing the paper and for the helpful comments

It is described in “2 Materials and Methods” that 300 g/ton of β-mannanase was supplemented to the BMA group. Why only one dose of β-mannanase was studied? Did you choose this supplement dose based on previous study or some standards? Do you think that the supplement dose may also have an important impact on egg quality?

Response: We choose the dose recommended by the manufacturer for poultry and registered with the Minister of Agriculture.  But yes, we believe that could be interesting to use different doses, that maybe could increase the egg quality.

In the abstract, author declared that the objective of this study was to evaluate whether dietary supplementation with β-mannanase can improve the quality of storage eggs from laying hens. However, almost all the differences in egg weight, albumen weight, yolk color, yolk pH and TBARS of eggs between control and BMA group occurred since day 0 and did not show regular changes during storage. Moreover, in the conclusion, only the effects of β-mannanase on the quality of eggs were proposed, not the storage quality. Why do you think the dietary supplementation with β-mannanase have some specific effects on the storage quality of eggs?

Response: I believe, as you said, that since the changes were not regular during storage, we can`t confirm an improvement during storage. Further studies, with different dosages, for example, may elucidate these questions better. We also will study the effects of the enzyme on the microbiota of the oviduct and the structure of the eggshell. These answers may help us to understand the mechanism of action of the additive.   

In order to better study the effect of dietary supplementation with β-mannanase on the the storage quality of eggs, indicators of egg freshness such as Haugh unit and yolk index should be measured?

Response: Yes, we agree. The Haught unit and yolk index can be found in table 1.

Although the effects of dietary supplementation with β-mannanase on the quality of storage eggs were discussed, but the mechanism was rarely explored. For example, why dietary supplementation with β-mannanase increased the eggshell weight? Was it to increase the thickness or density? In lines 315-318, author proposed that β-mannanase may facilitate the action of enzymes and increase the amount of protein absorbed. However, the results only show the increase of albumen weight not the protein content in albumen, and the increased weight might also be due to the increase content of water. Therefore, further studies such as the micro-structure of the eggshell, the composition of the albumen and yolk should be carried out to explore the action mechanism of β-mannanase.

Response: Thank you for the suggestions, we are currently studying the changes on the eggshell using electron microscopy, so we can better understand the findings of this study since there isn`t much described in the literature.

Table 9, “Probiotic” should be corrected to “”BMA

Response: Text altered as suggested

Round 2

Reviewer 1 Report

Dear Authors,

Adjustments have been made as needed.

Best regards,