Fluctuations in Goat Milk Composition During Processing
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper investigated the associations of goat milk somatic cell counts with milk quality parameters, such as milk fat, protein, dry matter, fat-to-protein ratio, and curd firmness, which are of paramount importance in cheese making. In addition, this research investigated seasonal variations in milk composition and their influence on curd firmness. Furthermore, the authors considered the effects of two different breeds and a cross-breed on milk composition and observed the differences within the groups of milk samples based on somatic cell count. Overall, this research provides valuable insights for both the scientific community and cheese producers, contributing to current knowledge on the effects of seasonal variation and somatic cell count on the cheese-making properties of goat milk. However, there is room for improvement, especially regarding the presentation of the results, which is often inconsistent. The text does not align with the results presented in tables; this should be checked. After that, the discussion and conclusion sections should be revisited accordingly.
Comments for author File: 
Comments.pdf
Generally, the english is solid.
Author Response
Dear Reviewer,
Thank you very much for valuable comments to our manuscript.
Comment 1: Line 35 to 38: maybe divide this long sentence into two, thus bringing more clarity.
Response 1: Thank you for pointing this out and we agree with the suggestion . Therefore we divide this long sentence in two. [Goat milk composition can be influenced by factors: breed, lactation, age, and parity [3,10,11,12,13]. Climate, season, farm management, milking system and feed [14,15,16,17], as well as oestrus cycle and stress [18] also impact the composition and suitability of milk for processing.] Page 1, Line 35 to 38.
Comment 2: Line 50: check the wording (maybe it should be „to analyze“)
Response 2: Thank you for pointing this out. We agree with this comment and change the wording from [analysing] to [to analyse]. Page 2, Line 50.
Comment 3: Line 86 to 88: check the calculation (it it was 2.0 kg of dry matter intake, how did the authors divide that into 0.5 kg , 1.5 kg and 0.5 kg)
Response 3: Thank you very much for valuable comment. We agree that calculation was incorrect. Therefore we have calculated accordingly and corrected the results in the manuscript [According to the author’s calculations, this was supplied by roughly 0.3 kg DM from hay, 1.5 kg DM of pasture herbage, and 0.2 kg DM from cereal grains.] Page 2, Line 87 to 88.
Comment 4: Line 129: Which software was used to perform ANOVA? If it were Excel, then state that in the parentheses, following the ANOVA, not preceding it.
Response 4: Thank you very much for valuable comment. We agree with the comment and therefore changed the sentence.[The statistical analysis was conducted using Descriptive Statistics and ANOVA (MS Excel Office 2016).] In this study the calculation were made with Excel software. Page 4, Line 129 to 130.
Comment 5: Check the formatting of the tables, remove the horizontal lines.
Response 5: Thank you for pointing this out. We agree with this comment and have made the changes in table formatting, removing the horizontal lines. Table 1 in Page 3, Table 2 in Page 4, Table 3 in Page 5, Table 4 in Page 7 and Table 5 in Page 7 to 8.
Comment 6: Table 2 should be cited in the text.
Response 6: Thank you very much for valuable comment. We agree with it. [Individual goat milk samples were collected to clarify milk composition and curd firmness data in relation to somatic cell count variations, and seasonal fluctuations were determined to establish a relationship between somatic cell and season (Table 2).] [High somatic cell count (Group IV - 9.08) significantly reduces curd firmness (Table 2), considerably lowering the results by 14% to 17% (1.56 N)...]
Table 2 have been citated in Line 137 and Line 153 to 154.
Comment 7: Line 142: The freezing point data are missing (maybe they should be in Table 2?)
Response 7: Thank you very much for valuable comment. We agree with this comment. Therefore we have added the freezing point data in Table 2. Page 4.
Comment 8: Line 142: based on the results from Table 2, it cannot be stated that higher SSC was associated with decreased protein content, only with dry matter.
Response 8: Thank you very much for valuable comment. We agree to this comment. We have accordingly modified this point and corrected the sentence. [Milk composition and coagulation characteristics were strongly affected by somatic cell count and higher SCS was associated with decreased freezing point and dry matter concentration, as well as a lower protein content and reduced curd firmness.] Page 4 Line 141 to 144.
Comment 9: Line 167 to 168: Rephrase the sentence for more clarity – the results from Figure 1 suggest that investigated levels of SSC had no association with analyzed parameters such as contents of milk fat, protein, lactose nor curd firmness. However, the results in Table 2 indicate significantly lower curd firmness for Group IV milk samples, so further analysis is required to confirm the relationship between high SCC and curd firmness.
Response 9: Thank you very much for valuable comment. We agree to this comment. We have, accordingly, changed the sentence to emphasize this point. [The presented data support the statement that SCC has a limited impact on milk composition. Curd firmness was affected by high SCC Group IV (Table 2), yet when all milk samples were analysed collectively, no strong relationship between these parameters was observed.] Page 5, Line 168 to 171.
Comment 10: Line 200 to 201: it should be “protein content” instead of “composition”, because the protein composition here is unknown, and it could be somewhat revealed by SDS PAG electrophoresis. The protein profile may be more important for curd firmness than gross protein content (the level of αs casein in milk). If the SDS PAGE now is not doable, the authors could state the limitations of the study in this regard and discuss the results from this point of view, cite the corresponding literature.
Response 10: Thank you for pointing this out. We agree with this comment and have made the changes wording to emphasize this point. [Curd firmness attained its minimum in early summer, coinciding with a decrease of the protein concentration.] Page 6, Line 204 to 205.
Comment 11: Figure 2. should be without horizontal lines. In addition, check the data presented, it seems that there is excess data.
Response 11: Thank you very much for valuable comment. We agree to this comment. We have, accordingly, deleted the horizontal lines in Figure 2. Data have been double checked and are correct. Page 6.
Comment 12: Line 217 to 218: Authors should correct the statement. The fat to protein ratio was influenced by breed only in Group II (Table 3), and no influence by stage of lactation was observed regarding this parameter (Table 4).
Response 12: Thank you very much for valuable comment. We agree to this comment. We have, accordingly, revised the sentences to emphasize this point. [The lactation (Table 4) and breed do not significantly impact the fat-to-protein ratio in goat milk (Table 3), only breed influence was established in Group II results. There were no established relationships between lactations within the Groups in fat concentration, but there were small differences in lactations between the Groups (Figure 1 and Table 4).] Page 7, Line 221 to 225.
Comment 13: Line 219: check that claim, as presented in Table 4, there is significant differences between fat content as influenced by SSC (for example, when we compare 2nd lactation, fat content in Group I is significantly higher than in Group II; the same applies for the 3rd lactation).
Response 13: Thank you very much for valuable comment. We agree to this comment and have explanation to emphasize this point: In this research we analysed most represented lactation in the farm (2nd, 3rd and 4th). To understand SCC in the goat milk we analysed factors that impact it as lactation, season and breed. Page 7, Line 223 to 225.
Comment 14: Lines 228 to 229: there are no significant differences in Group I between different lactation milks (lowercase letters are the same), as can be seen from Table 4, correct the statement.
Response 14: Thank you very much for valuable comment. We agree to this comment and make changes in the sentence. [The differences in protein concentration were observed in the 2nd lactation samples (3.35%) compared to the 3rd (3.17%) and the 4th (3.27%) lactation milk samples, differences were also found in Group III and Group IV. Page 8, Line 234 to 237.]
Comment 15: Line 239 to 240: Again, the fat to protein ratio did not differ significantly in the Group IV between the lactations (lowercase letters are the same), check statistics or correct the letters of significance.
Response 15: Thank you for pointing this out. We agree with this comment and have made the changes in the sentence to emphasize this point. [There were no significant differences found between the Groups for this parameter.]
Response to comment of the Quality of the English language: Thank you very much for valuable comment. We agree to this comment that language could be improved. Therefore we have ordered the English editing to the journal and wait for the results. At this moment we add the corrected manuscript without language editing.
Additional clarification: Thank you very much for the valuable comments. We made some changes in the conclusions (line 335 to 336). To see all made changes we add our corrected manuscript as an attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper deals with its stated objective (lines 71 and 72), which is good. However, some clarifications are required:
Somatic cell score equation needs more explanation on log2(SCC/100) +3. What does 3 denotes, please explain. I am familiar with the log to the base of 10, but not 2.
Tables 2 and 3: Since you have 4 columns, please describe your values with a, b, c, and d for every variable in each row. Show the highest value in each row with a and then go to the next higher value and show with b, and so on to c and d. It will be easier for your readers to comprehend the concept. The way that has been presented, is very hard to compare the values and is confusing.
In lines 145-146. Freezing point has not been shown in Table 2, so either delete this sentence or show the values for freezing point in Table 2.
Principal correlation analysis was performed for all milk samples and it is hard to if there are differences. I recommend to use the means of subgroups and you may see differences, if there are differences.
The statistical indicators in line 210, is not correctly stated and please correct it.
In Table 4, I only see stages of lactation and groups, but not breeds. Line 217 says "stage of lactation and breed" How tables 3 and 4 are compared. I do not understand how this was done. You are showing 2nd lactation, 3rd and 4th. What happened to the 1st stage of lactation and according to your table 3, you have 4 stages of lactation starting from Spring ...to Autumn.
Comments on the Quality of English Language
The English language can be improved, but over all the quality is acceptable, for instance in sentence 16, the word "the" before lower is not needed.
In sentence 31, the word higher is compared to what. It should be rephrased or changed to "high".
In sentence 42, it sounds better to have the word goats instead of goat. Also in some other places in the manuscript change the word from singular form to plural form - sentence 94, "the goat udder was" change to "the goat udders were"
In sentence 91, please change ", grouping them into groups" to "categorized within groups"
Author Response
Dear Reviewer,
Thank you very much for valuable comments to our manuscript.
Comment 1: Somatic cell score equation needs more explanation on log2(SCC/100) +3. What does 3 denotes, please explain. I am familiar with the log to the base of 10, but not 2.
Response 1: Thank you very much for valuable comment. We would like to explain our choice to this equation. The advantage of this evaluation lies in the normalization of the frequency distribution of SCC data for various statistical evaluations using parametric methods. This transformation equation for recalculation of individual dairy goat SCC on a linear score based on SCCs (SCSs) on a log - 2 basis. The main advantage of the SCS is the linearization of the SCC relationship to milk yield losses of dairy goats, mainly due to the occurrence of subclinical mastitis. The SCS scale was then used in scientific work as well as in practical breeding programs as a very suitable characteristic to control the dynamics of SCC development. Page 3.
Comment 2: Table 2 and 3: Since you have 4 columns, please describe your values with a, b, c, and d for every variable in each row. Show the highest value in each row with a and then go to the next higher value and show with b, and so on to c and d. It will be easier for your readers to comprehend the concept. The way that has been presented, is very hard to compare the values and is confusing.
Response 2: Thank you for pointing this out and we agree with the comment. Here is the explanation. The letters in each row follow the alphabetical order and are not associated with minimum or maximum values.
Comment 3: In lines 145-146. Freezing point has not been shown in Table 2, so either delete this sentence or show the values for freezing point in Table 2.
Response 3: Thank you very much for valuable comment. We agree with this comment. Therefore, we have added the freezing point data in Table 2. Page 4.
Comment 4: Principal correlation analysis was performed for all milk samples and it is hard to if there are differences. I recommend to use the means of subgroups and you may see differences, if there are differences.
Response 4: Thank you very much for valuable comment. We agree to this comment and can understand the recommendation. However, in the present study, the analysis was intentionally performed on all individual milk samples in order to preserve the natural variability within groups and to avoid potential bias introduced by data averaging. We therefore believe that the current presentation provides the most accurate and informative representation of the data, and no changes were made to the correlation analysis.
Comment 5: The statistical indicators in line 210, is not correctly stated and please correct it.
Response 5: Thank you for pointing this out and we agree with the comment. [Results indicated with the same uppercase letter in the columns do not differ significantly between the groups (p>0.05).] Page 7, Line 214 to 215.
Comment 6: In Table 4, I only see stages of lactation and groups, but not breeds. Line 217 says "stage of lactation and breed" How tables 3 and 4 are compared. I do not understand how this was done. You are showing 2nd lactation, 3rd and 4th. What happened to the 1st stage of lactation and according to your table 3, you have 4 stages of lactation starting from Spring ...to Autumn.
Response 6: Thank you very much for valuable comment. We agree to this comment. [The lactation stage of (Table 4) and breed do not significantly impact the fat-to-protein ratio in goat milk (Table 3), only breed influence was established in Group II results. There were no established relationships between lactations within the Groups in fat concentration, but there were small differences in lactations between the Groups (Figure 1 and Table 4).] In present study we analysed lactation numbers not stages. Table 3 and Table 4 are divided in SCS groups, and we can see how different factors (lactation and breed) also affect milk content. We analysed most represented lactation in the farm (2nd, 3rd and 4th). To understand SCC in the goat milk we analysed factors that impact it as lactation, season and breed. Page 7, Line 223 to 225.
Response to comment of the Quality of the English language: Thank you very much for valuable comment. We agree to this comment that language could be improved. Therefore we have ordered the English editing to the journal and wait for the results. At this moment we add the corrected manuscript without language editing.
We also corrected your comments about the language. [Results demonstrated that the milk samples from goats with the lower SCC (Group I) exhibited the highest fat (3.34%), lactose (4.56%) and dry matter (11.28%) concentrations, and fat-to-protein ratio (1.02). ] Page 1, Line 16. [The study findings demonstrate a higher SCC in goat milk [4,5,6,7] and sheep milk [8].] Page 1, Line 31. Changes from singular to pleeal form: [but in goats, the SCC is obscured by] Page 2, Line 42. [Prior to sample collection, the goat udder were cleaned and disinfected] Page 3, Line 94. We change wording [determined somatic cell count, categorised within groups and the results] Page 3, Line 91.
Additional clarification: Thank you very much for the valuable comments. We made some changes in the conclusions (line 335 to 336). To see all made changes we add our corrected manuscript as an attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript has been significantly improved and is suitable for publication.
Author Response
Dear Reviewer,
Thank you very much for valuable comments to our manuscript.
Comment 1: Figures and tables can be improved.
Response 1: Thank you very for pointing this out. We agree to this and have accordingly deleted the horizontal lines in Table 1. Page 3.
Response to comment of the Quality of the English language: Thank you very much for valuable comment. Therefore, we had received English language editing by MDPI. The text has been checked for correct use of grammar and common technical terms, and edited to a level suitable for reporting research in a scholarly journal.
Additional clarification: Thank you for helpful comments; the manuscript has been carefully checked and all necessary changes have been made accordingly.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe line numbering system in the old version is not sequential and there are brakes in numbering, for instance, from line 122 to 350 and in a few more places. The line numbering has changes in the new version and it is hard to compare the changes.
You did not explain every term in the equation of Somatic Cell, for instance
SCS = log2(SCC/100.000) + 3;
3 = constant represents ....
SCC/100.000 = represents ???
Comments on the Quality of English Language
The English language can be improved, but over all the quality is acceptable, for instance in sentence 16, the word "the" before lower is not needed.
In sentence 31, the word higher is compared to what. It should be rephrased or changed to "high".
In sentence 42, it sounds better to have the word goats instead of goat. Also in some other places in the manuscript change the word from singular form to plural form - sentence 94, "the goat udder was" change to "the goat udders were"
In sentence 91, please change ", grouping them into groups" to "categorized within groups"
Author Response
Dear Reviewer,
Thank you very much for valuable comments to our manuscript.
Comment 1: Explain every term in the equation of Somatic Cell.
Response 1: Thank you for pointing this out and we agree with the suggestion.
SCC (Somatic Cell Count): The number of somatic cells per millilitre of milk (cells/mL). It is a biological indicator of udder health, with higher values reflecting inflammation or mastitis.
100,000: A reference constant used to standardize SCC values. Dividing SCC by 100,000 expresses the count relative to a biologically meaningful baseline commonly used in dairy science.
log2\log_2 (base-2 logarithm): A logarithmic transformation that normalizes the highly skewed distribution of SCC data. Using base 2 ensures that each one-unit increase in SCS corresponds to a doubling of SCC, which simplifies interpretation and genetic analysis.
+3: A scaling constant added to shift the score to a convenient positive range. With this constant, an SCC of 100,000 cells/mL corresponds to an SCS of 3, a value close to the population average and easy to interpret statistically.
Together, this formulation converts SCC into a linear, normally distributed trait suitable for statistical modeling, comparison among animals, and genetic evaluation.
Comment 2: Figures and tables can be improved.
Response 2: Thank you very for pointing this out. We agree to this and have accordingly deleted the horizontal lines in Table 1. Page 3.
Response to comment of the Quality of the English language: Thank you very much for valuable comment. Therefore, we had received English language editing by MDPI. The text has been checked for correct use of grammar and common technical terms, and edited to a level suitable for reporting research in a scholarly journal.
Additional clarification: Thank you for helpful comments; the manuscript has been carefully checked and all necessary changes have been made accordingly.
Author Response File: Author Response.pdf
