Effect of an Enriched Elevated Platform Rearing System on the Welfare and Bone Quality of Fattening Pigs
, Sitong Zhou 1,†, Xin Li 1, Qin Fu 1, Xiaohong Zhang 1, Wenbo Ji 1 and Honggui Liu 1,2,*
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The manuscript entitled “Effect of Enriched Elevated Platform Rearing System on the Welfare and Bone Quality of Fattening Pigs” reveals important findings in addressing current concerns in animal welfare.
The study is scientifically sound. However, I have several concerns about the methodology used for gathering data on pig behavior that need to be addressed:
a. What is the rationale for conducting behavioral observations for only 8 hours a day, specifically from 07:00-11:00 and 13:00-17:00 every Monday and Friday?
b. Since pigs are fed ad libitum, their behavior should be monitored 24 hours a day to assess the effect of the enriched elevated platform rearing system. A 24-hour observation is recommended to fully understand pig behavior, particularly at night.
c. A researcher manually recorded the frequency of standing, lying, sitting, and other behaviors. Using algorithms and artificial intelligence, which are trending in current research, would be more accurate. Several studies have employed these methods, and the authors could reference them.
d. Besides the type of flooring, skin and limb lesions are also associated with the frequency of standing and the duration of lying. Studies have reported that lesions can occur when animals spend more time lying down due to a lack of oxygen reaching the tissue in the shoulder area from floor pressure, leading to tissue necrosis. I recommend including data on the duration of standing, sitting, and lying.
Best of luck in your future research endeavors.
Author Response
Reply to reviewer’s comments:
Thank you for your support and recognition of our work, and we also tend to continuously optimize this work in production practice. We are also very grateful for your valuable comments on our manuscript to help us improve the quality of the manuscript.
a. What is the rationale for conducting behavioral observations for only 8 hours a day, specifically from 07:00-11:00 and 13:00-17:00 every Monday and Friday?
Response: We selected the period when pigs were relatively active in a day and avoided the period when there may be artificial interference factors, such as feeding and cleaning.
b. Since pigs are fed ad libitum, their behavior should be monitored 24 hours a day to assess the effect of the enriched elevated platform rearing system. A 24-hour observation is recommended to fully understand pig behavior, particularly at night.
Response: Thank you very much for your suggestion. We will continue to improve the behavioral content and observation methods in the future work
c. A researcher manually recorded the frequency of standing, lying, sitting, and other behaviors. Using algorithms and artificial intelligence, which are trending in current research, would be more accurate. Several studies have employed these methods, and the authors could reference them.
Response: Thank you very much for your suggestion. As you mentioned, our team is working on improving the accuracy of data through machine learning and behavior recognition systems, and which will be presented in the later articles.
d. Besides the type of flooring, skin and limb lesions are also associated with the frequency of standing and the duration of lying. Studies have reported that lesions can occur when animals spend more time lying down due to a lack of oxygen reaching the tissue in the shoulder area from floor pressure, leading to tissue necrosis. I recommend including data on the duration of standing, sitting, and lying.
Response: We quite agree with your suggestion. In this study, we converted the duration of state behaviors into time proportion, and analyzed them between groups. We will further analyze the behaviors and their impacts in future research.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors
Dear Authors, I have carefully read the paper and I have just a minor suggestions for improvement before final acceptance. The first one is to clarify housing of the animals: are all animals in the same building under same microclimate parameters? The other one is to improve conclusion as suggested in the manuscript: please, rewrite.
Comments for author File: Comments.pdf
Comments on the Quality of English Language
Minor changes are required: line 351, e.g., in that replace by "where".
Author Response
Reply to reviewer’s comments:
Thank you for your support and recognition of our work, and we also tend to continuously optimize this work in production practice. We are also very grateful for your valuable comments on our manuscript to help us improve the quality of the manuscript.
Dear Authors, I have carefully read the paper and I have just a minor suggestion for improvement before final acceptance. The first one is to clarify housing of the animals: are all animals in the same building under same microclimate parameters? The other one is to improve conclusion as suggested in the manuscript: please, rewrite.
Response: Thank you very much for your suggestion. We have added the following information in section 2.1, which is “…the specifications and microclimate parameters of the two barns are identical”. In addition, according to your suggestion, we revised the conclusion to “Taken together, environmental enrichment in the elevated platform rearing system can increase weight gain and the expression of positive behaviors, and reduce negative behaviors and its damage to the organism in fattening pigs. Therefore, the elevated platform rearing system is a physical environment enrichment rearing system, which provides an essential theoretical basis for improving pig health and animal welfare-type pig housing”.
Minor changes are required: line 351, e.g., in that replace by "where".
Response: It has been corrected.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors
Line 53 referencing style
Line 55 again
Line 77 (Yorkshire ♂ × Landrace ♂ × Yorkshire ♀) should be Yorkshire ♂ × (Landrace ♂ × Yorkshire ♀)♀
Line 110 ad libitum in italic
Line 142 instead of …by scanning sampling… write …using a scanning sampling…
Line 163 selected at random??
Line 212 Levene’s
Line 247-249 rephrase sentence, revise English
Table 3 remove superscripts. We don’t need these as we have the p values.
Your set of behaviours should follow two main rules, being exhaustive (no behaviours left without being registered), and the behaviours need to be independent of each other (no overlaps or confusions). While for the state behaviours we can see that (each behaviour different of each other and the pigs are always in one of the 3 states), that is not the case for the event behaviours. Please note the pigs may be performing a behaviour not identified,… we normally overcome the issue by stating “other behaviours”. However, the main concern is the possible overlap of behaviours. To avoid confusion you need to be specific and define the behaviours. I therefore, ask you to include in your methodology a description of each of the behaviours to avoid overlapping confusion. Also include a limitation in your methods acknowledging that other behaviours were not considered in your analysis.
Line 267 on Table 3 notes you write “The event behaviors were quantified as the number of occurrences (time/day)” My question is if this was recorded as the number of events the unit is not time,… is it? Or did you measure minutes instead? In your methodology section you refer to the percentage of the time observed for state behaviours and number of times for event behaviours. Please clarify.
Table 4 again superscripts not needed. Please remove.
Line 390 referencing style
Line 518 remove breeding
Line 519 remove “and creating new breeding models.” You didn’t study effects on breeding.
Comments on the Quality of English Language
minor issues
Author Response
Reply to reviewer’s comments:
Thank you for your support and recognition of our work, and we also tend to continuously optimize this work in production practice. We are also very grateful for your valuable comments on our manuscript to help us improve the quality of the manuscript.
Line 53 referencing style
Response: It has been corrected.
Line 55 again
Response: It has been corrected.
Line 77 (Yorkshire ♂ × Landrace ♂ × Yorkshire ♀) should be Yorkshire ♂ × (Landrace ♂ × Yorkshire ♀)♀
Response: It has been corrected.
Line 110 ad libitum in italic
Response: It has been corrected to italics.
Line 142 instead of …by scanning sampling… write …using a scanning sampling…
Response: It has been corrected to “…using a scanning sampling…”.
Line 163 selected at random??
Response: Yes! And it has been corrected to “…randomly selected…”.
Line 212 Levene’s
Response: It has been corrected.
Line 247-249 rephrase sentence, revise English
Response: This part has been corrected to “The statistical results of event and state behaviors were shown in Table 3.”.
Table 3 remove superscripts. We don’t need these as we have the p values.
Response: According to your suggestion, we deleted superscripts.
Your set of behaviours should follow two main rules, being exhaustive (no behaviours left without being registered), and the behaviours need to be independent of each other (no overlaps or confusions). While for the state behaviours we can see that (each behaviour different of each other and the pigs are always in one of the 3 states), that is not the case for the event behaviours. Please note the pigs may be performing a behaviour not identified,… we normally overcome the issue by stating “other behaviours”. However, the main concern is the possible overlap of behaviours. To avoid confusion you need to be specific and define the behaviours. I therefore, ask you to include in your methodology a description of each of the behaviours to avoid overlapping confusion. Also include a limitation in your methods acknowledging that other behaviours were not considered in your analysis.
Response: We fully understand your concern. We have described the definition of behaviors in detail in Table 2. According to your suggestion, we added the limitation in section 2.3, that is, “In addition to the above behaviors, other behaviors were not involved in the analysis process.”
Line 267 on Table 3 notes you write “The event behaviors were quantified as the number of occurrences (time/day)” My question is if this was recorded as the number of events the unit is not time, … is it? Or did you measure minutes instead? In your methodology section you refer to the percentage of the time observed for state behaviours and number of times for event behaviours. Please clarify.
Response: This is our oversight, and it should be "times" here. It has been corrected.
Table 4 again superscripts not needed. Please remove.
Response: It has been corrected.
Line 390 referencing style
Response: It has been corrected.
Line 518 remove breeding
Response: It has been removed.
Line 519 remove “and creating new breeding models.” You didn’t study effects on breeding.
Response: It has been removed.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
The authors did not make any changes regarding my concerns; however, they justified that some of my comments on data gathering in pig behavior will be addressed in future research. I fully understand since the study was already terminated. Hence, I recommend this paper for publication in the journal.
