Precision Feeding on Pig Fattening Farms: Can Simplified Implementation Enhance Productivity and Reduce Pollutant Emissions?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors:

The title should be revised, as sustainability goes beyond pollutant emissions and production profitability, including many additional aspects. A more suitable option would be to focus the title solely on the use of PF and its effect on greenhouse gas emissions.

The abstract highlights the economic benefits of AI-driven tools for real-time diet formulation, but it is unclear whether AI is truly the study’s primary focus. The paper’s objective and scope are insufficiently defined.

The introduction cites Agricultural Outlook 2020–2029, but the 2025–2035 edition is now available with updated projections. Please replace the citation with the latest edition.

Beginning at line 51, you note that emission-reduction techniques at the start of the chain (nutritional strategies) are important. While accurate, from both environmental and production standpoints the chain actually begins upstream with feed-ingredient manufacturing, which is a major environmental hotspot. Please clarify the paragraph to include this point.

Line 67 attributes a 6% reduction in greenhouse gas emissions to increasing individual nutrient efficiency and cites Pomar and Remus (2029). However, those data come from Andretta et al. (2018). It is important to be more rigorous in the assigning of sources.

Line 259: It is not clear how the gas concentrations were determined. Was the ppm concentration obtained from the sensors (line 290) used? Please clarify.

Line 267 onward: Was an airtightness test performed? If not, how was a neutral air-flow balance determined?

Figures 7, 8, and 9: Please do not smooth the lines.

It is unclear whether the reported gas results correspond to cumulative measurements or only to point (instantaneous) values. In addition, Table 8 presents only average values, without showing differences by strategy, by time, or by the interaction of both. In environmental control and monitoring studies, it is essential to report total values because, while statistical analysis is important, it does not by itself reflect the real or overall environmental impact.

Although it would be logical to expect differences between high- and low-cost feed ingredients, these were not compared with each other, which raises doubts about the rest of the results. For the experiment, were expensive ingredients used in all diets, inexpensive ones in all, or a combination of both? This point must be clarified; otherwise, the results presented are incomplete, since only a single value is reported without specifying whether it corresponds to high- or low-cost ingredients.

In conclusions, it is not correct to state: “For instance, increased dietary fiber led to higher CH4 and CO2 emissions, highlighting the need for dietary formulation to manage both nutrient excretion and environmental impact,” since multiple factors were involved in this study and those effects were not isolated. It is recommended to remove this conclusion.

It is not entirely correct to state: “However, even partial implementation of PF concepts, as exemplified by this trial, can yield significant economic savings, especially under situations of high market prices for protein raw materials,” because no comparative statistical analysis was conducted between the Low feed cost and High feed cost strategies. It is recommended to remove this comment.

Conclude solely based on your objectives and results. If you wish to include an implications section, go ahead, it is highly recommended, but it should not be placed in the conclusions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This is a very well written manuscript to summarize a trial designed to compare conventional vs blend feeding, using a simplified animal feeding study. I didn't find any major flaws in the trial design. The results are clearly presented and explained. The entire manuscript follows logics and is easy to read. 

However, I am curious if the authors considered plugging the production outputs into an Life-Cycle Assessment model? We know the environmental benefits/disadvantage is not just about N emission, but its consequences. We've seen other research groups did animal trials and then added the LCA data to help understand the bigger systematic environmental impact. Also, geographic regions can play a huge role in environmental impacts. I think either the authors should explore these analyses or mention them as limitations in the discussion.   https://doi.org/10.1016/j.jclepro.2025.145368   https://doi.org/10.1093/jas/skac356

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

overall this manuscript contributes a very interesting approach and development in animal nutrition!

line 66 clarify: excretion of what?

70: which amino acids?

line 789: Oenema, not Onema.

line 74: EU reference paper which is 11 years old. What does this contribute?

line 218: Why not include phytase and why include on the contrary monocalcium phosphate?

fig 6 Y axis left and right should be equal and starting from zero to make comparisons well

fig 7: it is not clear to me what the time in weeks mean: is this between pH measurement and collection of manure or is it the pH of the manure at the differnt collection times? the same question for the following figures

Table 7 Why such big differences between DM and OM and TKN between (C) and (BF) and also between start and end of the test?

why BF TKN 3177 becomes 2711 while the NH3 starts at 2363 and ends 1360?

why N-NH3 is 1884/2298= 82% which is extremely high in conventional even much higher than for BF?

 

Author Response

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Author Response File: Author Response.pdf