The Effect of Fermented Kefir as Functional Feed Additive in Post-Weaned Pigs
Round 1
Reviewer 1 Report
Dear authors
General comments
Language should be revised and improved by avoiding informal words (So, but, …..)
The style should be improved to a direct and concise one
In the section results, numerical values should be added. Also, the language should be improved and then checked.
Discussion is poorly written. Results should be further discussed.
The conclusion is missing.
Section. Abstract
Methods should be added
Numerical values should be added to corroborate the conclusions.
Section. Introduction.
Line 38-39. “However, the use of antibiotics in livestock accelerates the occurrence of antibiotic resistant pathogens, which is a major concern for human health, both directly and indirectly.”
The direct and indirect risks for the human health should be explained.
Line 43-50. This subsection is poorly written and more important details regarding the Kefir and its biological activities are missing.
Section. Material and Methods
Line 61. Correct “at 30 C for 2 d” to at 30° C for 2 days
Lines 60-77. 2.1. Preparation of fermented kefir
This subsection should be divided into two distinct sections
- Preparation of kefir
- Determination of cells growth
Line 79. 2.2. “Experimental design of the field test” should be rewritten to “Animals”
Line 91. 2.3. Analysis of microorganisms in fecal sample of pigs by treatment of kefir
Should be corrected to Analysis of microorganisms in fecal sample of pigs
Line 100. 2.4. Analysis of immunological factors in serum of pigs by treatment of kefir Should be corrected to Analysis of immunological factors in serum of pigs
Lines 101-102. “In order to analyze immunological factors like porcine TNF-α, IL-6, IgA, and IgG in blood serum”
This sentence should be removed. Write in a direct and concise style.
Section. Results
Lines 120-125. “We tried to optimize the culture …… the inoculation size of seed culture.” This paragraph should be summarized since the M&M gives these details.
Lines 126-132. “As a result, the number of lactic acid bacteria, …… and size of inoculum (Table 1).
This paragraph should be rewritten in a direct and concise style with adding numerical values.
Lines 141-142. 3.2. Fermented kefir increases the number of beneficial microorganism but prevent the growth of pathogens
This subtitle should be rewritten in a correct style.
Lines 143-144. The microbial population and diversity in the gut of the pig directly affect the immune system as well as the efficient digestion of feed.
This sentence should be removed and can be discussed in the discussion.
Lines 166-167. This subsection should be rewritten in a more correct style.
Line 182. “The kefir feed was fed ad libitum for the period of this field trial.” This sentence should be rewritten in a correct style.
Lines 182-188. The style should be improved and corrected.
Section. Discussion.
Lines 193-195. The need of functional feed additives ….. resistance [6–9]. Should be rewritten and corrected.
The discussion should be improved by further comparison with previous studies. Also the possible mechanisms should be discussed.
Regards
Author Response
Response to Reviewer 1 Comments
Dear authors
General comments
Language should be revised and improved by avoiding informal words (So, but, …..)
The style should be improved to a direct and concise one
In the section results, numerical values should be added. Also, the language should be improved and then checked.
Discussion is poorly written. Results should be further discussed.
The conclusion is missing.
First of all, I appreciate reviewer 1 comments and will ask English editing in MDPI office.
Section. Abstract
Point 1: Methods should be added
Response 1: We already wrote brief method (Line 63-66) in my manuscript.
Point 2: Numerical values should be added to corroborate the conclusions.
Response 2: According to reviewer 1 comment, I fixed some sentences in revised manuscript.
Section. Introduction.
Point 3: Line 38-39. “However, the use of antibiotics in livestock accelerates the occurrence of antibiotic resistant pathogens, which is a major concern for human health, both directly and indirectly.” The direct and indirect risks for the human health should be explained.
Response 3: According to reviewer 1 comment, I fixed this sentence to “which is a major concern like the emergence of antibiotic-resistant microorganisms” in revised manuscript.
Point 4: Line 43-50. This subsection is poorly written and more important details regarding the Kefir and its biological activities are missing.
Response 4: According to reviewer 1 comment, I fixed this section newly in revised manuscript.
Section. Material and Methods
Point 5: Line 61. Correct “at 30 C for 2 d” to at 30° C for 2 days
Response 5: According to reviewer 1 comment, I fixed this section newly in revised manuscript.
Lines 60-77. 2.1. Preparation of fermented kefir
Point 6: This subsection should be divided into two distinct sections
Preparation of kefir
Determination of cells growth
Response 6: According to reviewer 1 comment, I separated this section to two subsections and rewrote these sections in revised manuscript
Point 7: Line 79. 2.2. “Experimental design of the field test” should be rewritten to “Animals”
Response 7: According to reviewer 1 comment, I fixed to “experimental design of animals” in revised manuscript.
Point 8: Line 91. 2.3. Analysis of microorganisms in fecal sample of pigs by treatment of kefir Should be corrected to Analysis of microorganisms in fecal sample of pigs
Response 8: According to reviewer 1 comment, I fixed to “Analysis of microorganisms in fecal sample of pigs” in revised manuscript.
Point 9: Line 100. 2.4. Analysis of immunological factors in serum of pigs by treatment of kefir Should be corrected to Analysis of immunological factors in serum of pigs
Response 9: According to reviewer 1 comment, I fixed to “Analysis of porcine TNF-α, IL-6, IgA, and IgG in serum of pigs” in revised manuscript.
Point 10: Lines 101-102. “In order to analyze immunological factors like porcine TNF-α, IL-6, IgA, and IgG in blood serum” This sentence should be removed. Write in a direct and concise style.
Response 10: According to reviewer 1 comment, I removed “In order to analyze immunological factors like porcine TNF-α, IL-6, IgA, and IgG in blood serum” in revised manuscript.
Section. Results
Point 11: Lines 120-125. “We tried to optimize the culture …… the inoculation size of seed culture.” This paragraph should be summarized since the M&M gives these details.
Response 11: According to reviewer 1 comment, I fixed this part to “For the main fermentation of kefir, seed culture was carried out in sterilized 10% whole fat milk medium for 2 days at 30°C without agitation.” in revised manuscript.
Point 12: Lines 126-132. “As a result, the number of lactic acid bacteria, …… and size of inoculum (Table 1). This paragraph should be rewritten in a direct and concise style with adding numerical values.
Response 12: According to reviewer 1 comment, I fixed this part to “As a result, the number of lactic acid bacteria, Bacillus spp., and yeast increased by 123.6%, 115.4%, and 113.4%, respectively, when we used 2% of glucose. At 1% of whey protein, the number of lactic acid bacteria, Bacillus spp., and yeast increased by 122.7%, 120.2%, and 111%, respectively. At 0.02% and 0.1% of dipotassium phosphate, the number of lactic acid bacteria, Bacillus spp., and yeast was not reduced, compared to other concentration of dipotassium phosphate (Figure 1a-c).” in revised manuscript.
Point 13: Lines 141-142. 3.2. Fermented kefir increases the number of beneficial microorganism but prevent the growth of pathogens This subtitle should be rewritten in a correct style.
Response 13: According to reviewer 1 comment, I fixed this part to “The effect of fermented kefir on microflora in the fecal sample of post weaned pigs” in revised manuscript.
Point 14: Lines 143-144. The microbial population and diversity in the gut of the pig directly affect the immune system as well as the efficient digestion of feed. This sentence should be removed and can be discussed in the discussion.
Response 14: According to reviewer 1 comment, I removed this part in revised manuscript.
Point 15: Lines 166-167. This subsection should be rewritten in a more correct style.
Response 15: According to reviewer 1 comment, I fixed this part to “The effect of fermented kefir on innate immunity of post-weaned pigs” in revised manuscript.
Point 16: Line 182. “The kefir feed was fed ad libitum for the period of this field trial.” This sentence should be rewritten in a correct style.
Response 16: According to reviewer 1 comment, I remove this part and fixed to “We also determined the effect of fermented kefir on ADG and FCR as well as innate immunity of post-weaned pigs.” in revised manuscript.
Point 17: Lines 182-188. The style should be improved and corrected.
Response 17: According to reviewer 1 comment, I fixed this part to “The effect of fermented kefir on ADG and FCR as growth performances of post-weaned pig” in revised manuscript.
Section. Discussion.
Point 18: Lines 193-195. The need of functional feed additives ….. resistance [6–9]. Should be rewritten and corrected.
Response 18: According to reviewer 1 comment, I fixed this part to “The use of antibiotics is now restricted for the prevention of microbial infections because of antibiotic resistance so the need of functional feed additives as antibiotic alternatives in animal farming has increased” in revised manuscript.
Point 19: The discussion should be improved by further comparison with previous studies. Also the possible mechanisms should be discussed.
Response 19: According to reviewer 1 comment, I added regarding previous studies for comparison with our results in revised manuscript. And I rewrote the conclusion in revised manuscript.
Regards
Reviewer 2 Report
- Line 43 - Kefir is known to be traditional yogurt of fermented kefir grain with microbial complexes containing kefiran as the biologically active exopolysaccharide [4].
Kefir is a fermented milk beverage
- Line 64-66: “we modified the composition of glucose, whey protein, and dipotassium phosphate and the inoculation size and chose best compositions of each factors to increase number of viable lactic acid bacteria, Bacillus spp. and yeast “and Line 119 - The optimization of culture condition for kefir fermentation –please explain how it was performed
- Line 70-76 - “After fermentation, the total cells were harvested by continuous centrifugation at 8,000 rpm the cell pellet was mixed with 20% (w/v) of sterilized skim milk solution. After that, this mixture was lyophilized for 3 d. For determination of the number of lactic acid bacteria, Bacillus spp. and yeast in the lyophilized kefir, viable cell counting was carried out.
- Line 86-89 – what was lyophilized– cells or kefir ? it is not clear, please complete the methodology
- Lyophilized or freeze-dried is the better word?
- Line 157 – “even though no use of antibiotics” ? Please explain, because the methodology does not mention the addition of antibiotics to the feed
- Line 203 – 13 – missing [ ]
Author Response
Response to Reviewer 2 Comments
Point 1: Line 43 - Kefir is known to be traditional yogurt of fermented kefir grain with microbial complexes containing kefiran as the biologically active exopolysaccharide [4].
Kefir is a fermented milk beverage
Response 1: I agreed reviewer 2 comment. So, according to reviewer 2 comment, I fixed to “Kefir is known to be fermented milk by kefir grain with microbial complexes containing kefiran as the biologically active exopolysaccharide” in revised manuscript.
Point 2: Line 64-66: “we modified the composition of glucose, whey protein, and dipotassium phosphate and the inoculation size and chose best compositions of each factors to increase number of viable lactic acid bacteria, Bacillus spp. and yeast “and Line 119 - The optimization of culture condition for kefir fermentation –please explain how it was performed
Response 2: I agreed reviewer 2 comment. So, according to reviewer 2 comment, I fixed this part to “The basal medium for optimization of each components was composed of 1% of glucose, 0.5% of whey protein, 0.01% of dipotassium phosphate, 2% of yeast extract, 0.1% of ammonium sulfate, 0.01% of MgSO4, and 0.05% of MnSO4. We modified the composition of glucose, whey protein, and dipotassium phosphate one by one. And we chose best compositions of each factors to increase number of viable lactic acid bacteria, Bacillus spp. and yeast through viable colony counting.” in revised manuscript.
Point 3: Line 70-76 - “After fermentation, the total cells were harvested by continuous centrifugation at 8,000 rpm the cell pellet was mixed with 20% (w/v) of sterilized skim milk solution. After that, this mixture was lyophilized for 3 d. For determination of the number of lactic acid bacteria, Bacillus spp. and yeast in the lyophilized kefir, viable cell counting was carried out.
Response 3: I fixed “viable cell counting” this part to “viable colony counting” in revised manuscript.
Point 4: Line 86-89 – what was lyophilized– cells or kefir ? it is not clear, please complete the methodology
Response 4: I already mentioned that cell after centrifugation of kefir was lyophilized with 20% skim milk as a cryoprotective agent.
Point 5: Lyophilized or freeze-dried is the better word?
Response 5: I think that “lyophilized” might be better even if the meaning of two words is exactly same.
Point 6: Line 157 – “even though no use of antibiotics” ? Please explain, because the methodology does not mention the addition of antibiotics to the feed
Response 6: I agreed reviewer 2 comment. So, according to reviewer 2 comment, I removed “even though no use of antibiotics” in revised manuscript.
Point 7: Line 203 – 13 – missing [ ]
Response 7: According to reviewer 2 comment, I added [] at 16 in revised manuscript.
Round 2
Reviewer 1 Report
Dear authors
Many thanks for the corrections made
Best regards
