Concentrations and Emissions of Ammonia from Different Laying Hen Production Systems of Conventional Cage, Aviary and Natural Mating Colony Cage in North China Plain

Round 1

Reviewer 1 Report

The paper tackles a very relevant topic, which fits the aims and scopes of the journal. The results look promising and the description of the methodology appears to be fine. However, I do not consider it can be published in the present form due to some significant weaknesses. The findings obtained may be compromised because of these issues. Three main points are addressed as suggestions to improve the quality of the manuscript prior to publication:

1.- The periods of data collection seem to be very short and discontinuous to obtain significant conclusions. It would be advisable to have a larger and more robust database. Otherwise, try to explain up to which point and why the periods of time considered can be representative. The paper would benefit as well from analysing the outdoors meteorological conditions and how is the corresponding impact on the results.

2.- Apparently the data correspond just to three particular laying hen houses. I wonder how this fact can affect the results. For instance: is the selected CC representative of (most of) the CC laying hen houses? Or up to what limit? And similarly with AV and NM. I would have expected data from different laying hen houses of each type, or at least some comments on this issue.

3.- A lot of data are shown in nice tables and graphics, but the authors are expected to provide a deeper discussion on them. I find that sometimes it is just a description, without an insight which would be very recommended to present.

Author Response

Dear reviewer,

    Thanks for your comments on our manuscript. We have carefully considered the comments and made extensive revisions for our manuscript accordingly. The responses point to point were attached. 

Author Response File: Author Response.docx

Reviewer 2 Report

This scientific paper is very interesting and represents a good basis for research, ie it represents the detection of ecological parameters in laying facilities in conditions specific to NCP.
Therefore, I would like to reformulate the conclusions in such a way as to be an indicator of the current situation and a guide in further research on this topic.
My remark would be that the diversity of conditions and the results obtained in them is a little too great, for a more scientific approach I would try to equalize all the factors that can affect the formation of ammonia as much as possible and then draw conclusions based on such results.
Other minor corrections are in the comments of the manuscript.

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

Thank you very much for the comments on our manuscript. We have carefully considered the comments and made extensive revisions for our manuscript accordingly. And the file of responses point-by-point was attached.

Author Response File: Author Response.docx