Review Reports - Tannin Supplementation Alters Foraging Behavior and Spatial Distribution in Beef Cattle

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Although the English is largely comprehensible, it needs to be edited moderately to extensively for clarity and flow.

Limitation

Generalizability and statistical power are limited to six paddocks, three for each treatment.
The 60-day grazing period might not account for long-term effects on productivity or behavioral adaptation.
There are no metabolic or physiological indicators (such as blood nitrogen or rumen indicators) to back up behavioral interpretations.
Results may be distorted by variations in the weather variation between years 2023 and 2024, however they are not sufficiently discussed or modeled.
Results specifically support established tannin effects; nevertheless, there is a lack of mechanistic insight or economic evaluation.

Data

Although mean ± SE is typically reported in the manuscript, some parts where the confidence intervals and n values are unclear.
Excessive precision is used while reporting certain p-values.
Figures and tables provide useful information, but the descriptions are too wordy.
Numerical differences must be summed up in conclusion and abstract without emphasizing trends that are not significant.

Comments on the Quality of English Language

A comprehensive, expert language edit is advised to improve the text's structure, clarity, and flow.

Author Response

Response to Reviewer 1 Comments

Summary

We thank Reviewer 1 for the constructive feedback provided. The suggestions have helped us clarify the scope and strengthen the scientific presentation of our manuscript. All corresponding revisions are highlighted in the revised version of the paper, and detailed responses are provided below.

Limitation 1: Generalizability and statistical power are limited to six paddocks, three for each treatment.

Limitation 1 – Generalizability and power (six paddocks)

Author response:

We agree that the number of paddocks is modest; however, this issue is explicitly addressed in the design and analysis. In the revised manuscript, we clarified in Section 2.5 (Statistical Analysis, lines 309–311) that, although only six paddocks (three per treatment) were available, replication across two consecutive grazing seasons (2023 and 2024) was used to improve temporal robustness and reduce year-specific bias, and paddocks were treated as experimental units with cows nested within paddocks to account for within- and between-group variation (lines 318–319). This two-year replication and nested mixed-model structure were specifically adopted to counterbalance the limited number of paddocks and to support reliable treatment-level inference.

Limitation 2: The 60-day grazing period might not account for long-term effects on productivity or behavioral adaptation.

Response2:

We agree that a 60-day grazing period may not fully capture longer-term performance and metabolic responses to tannin supplementation. In the revised manuscript, we now emphasize both where this duration applies and how it may have constrained responses. In the Results, we specify that cow body weight change was evaluated over the 60-day experimental period (Section 3.1, lines 380–382), and in the Discussion we explicitly state that the relatively short duration of this study (60 days) may have limited the expression of significant improvements in calf body weight gain (Section 4.3, lines 747–748). We also compare our findings with longer-term studies (≥90–120 days) that reported clearer performance responses to tannin-rich diets (Section 4.3, lines 749–754) and conclude that prolonged exposure beyond the 60-day window used in the present study may be necessary to realize the full physiological potential of bioactive tannins, as improvements in weight gain and metabolic adaptation often require extended timeframes under free-grazing systems (Section 4.3, lines 755–758). Finally, the Study Limitations section explicitly notes that the 60-day duration may have limited the statistical power to detect subtle performance differences (Section 4.7, lines 873–877). Nevertheless, a 2-month period is enough duration to detect differences between treatments explored in this study, as revealed by the differences found. Moreover, this specific study explored differences expected to occur in the short term instead of in a chronic fashion.

Limitation 3: There are no metabolic or physiological indicators (e.g., blood nitrogen or rumen indicators) to back up behavioral interpretations.

Response3
Author response:

We appreciate this comment. In the revised manuscript, we clarify how physiological information from the same experimental platform is used to support the behavioral interpretation, and where the absence of new measurements in this specific trial is acknowledged. In Section 4.4, we summarize prior findings from the same grazing system showing that tannin-supplemented cows expressed a 28% reduction in blood urea nitrogen (BUN), indicating improved nitrogen retention and reduced ammonia burden (lines 775–777). We then connect these physiological changes to the behavioral patterns observed here: Section 4.4 (lines 781–795) explains thermoregulatory and microbial mechanisms aligned with greater evening grazing, reduced evening rumination, and cooler-period foraging. At the same time, we explicitly state that in this particular experiment we did not collect new blood metabolites, rumen fermentation parameters, or thermal stress markers, and we recommend including these indicators in future work to directly validate the proposed mechanisms under similar free-grazing conditions (Study Limitations, Section 4.7, lines 874–878).

Limitation 4: Results may be distorted by variations in the weather between years 2023 and 2024, which are not sufficiently discussed or modeled.

Response 4:

We appreciate this comment. The two-year structure of the experiment and the statistical modeling were specifically designed to account for interannual differences, including weather-related variation. In the Methods, we indicate that biomass sampling and grazing were repeated every 15 days across four periods over two consecutive years of the experiment (Section 2.3.1, lines 157–159), thereby capturing seasonal and interannual variation in forage availability and conditions. In the Statistical Analysis section, we clarify that biomass removal, nutrient composition, animal performance, and behavioral variables were analyzed using a factorial design including year × period × time of day (TOD) within a generalized linear mixed model framework (Section 2.5, lines 298–300). Thus, year effects and their interaction with period and TOD are explicitly modeled rather than ignored. Furthermore, in the Discussion we interpret behavioral responses within a thermal and climatic context: evening grazing in the present study is described as conferring thermoregulatory and metabolic benefits because cooler conditions reduce heat load and maximize access to sugar-rich forage, whereas rumination during hot periods elevates core body temperature (Section 4.4, lines 776–778). Finally, in the Study Limitations and Future Directions, we explicitly acknowledge that weather variability, particularly fluctuations in mid-summer rainfall and temperature, could have influenced forage quality and animal responses (Section 4.7, lines 861–863), indicating that this source of variation is recognized and discussed in the manuscript rather than overlooked.

Limitation 5: Results specifically support established tannin effects; nevertheless, there is a lack of mechanistic insight or economic evaluation.

Response 5:

We agree that clear mechanistic links and forward-looking context are important, and we have strengthened both in the revised manuscript. In Section 4.3 (lines 717–735), we now describe in detail how increased water intake in TT cows reflects physiological adjustments associated with tannin metabolism, including renal clearance of tannin–protein complexes, maintenance of ruminal osmotic balance, dilution of ruminal toxins, support of microbial activity, and the trade-offs these pose in arid and semi-arid rangelands where water is limited. In the same section we emphasize that tannin supplementation can enhance nitrogen efficiency, reduce methane emissions, and support animal health, while noting that these benefits must be weighed against water constraints (lines 724–733). In Section 4.4 (lines 763–767 and 782–785), we further develop the mechanistic narrative by linking evening grazing in TT cows to peaks in forage sugars and soluble proteins, and explaining how protein–tannin complexes stabilize rumen nitrogen, slow proteolysis and ammonia release, delay satiety, extend intake, and enhance microbial activity, thereby aligning behavioral plasticity (more evening grazing, less rumination) with thermoregulation and improved nitrogen utilization. Section 4.5 (lines 792–802 and 815–819) then connects these metabolic and behavioral changes to more uniform grazing distribution, reduced overuse of patches, and clearer links between animal behavior, spatial use of monoculture pastures, and ecological outcomes. Regarding economic and broader systems implications, the Study Limitations and Future Directions section explicitly calls for future work to examine interactions between tannins and other plant secondary metabolites and to use targeted and untargeted metabolomics to link biochemical pathways with performance and environmental outcomes (Section 4.7, lines 871–873). It would be impossible to complete a study with multiple layers of variables and implications such as economics. This will entail different studies and manuscripts.. The same section also notes the need to integrate multi-sensor behavioral datasets in modeling frameworks and to conduct economic assessments of tannin supplementation that consider supplement cost, water requirements, animal performance, and ecosystem service outcomes (Section 4.7, lines 878–882). Finally, the Conclusions explicitly state that future research should determine optimal dosage across contrasting rangeland systems and assess economic feasibility using metabolomic and isotopic approaches that integrate behavioral, physiological, and ecological responses (Section 5.0, lines 903–904).

Data-Related Comments

Data 1: Although mean ± SE is typically reported, some confidence intervals and n values are unclear.

Response 1:

We thank the reviewer for this observation. In the revised manuscript, we clarified how summary statistics are reported and where sample sizes can be found. In Section 2.5 (Statistical Analysis, lines 320–322), we now explicitly state that results are presented as back-transformed least-squares means (LSmeans) with their standard errors (SE). Confidence intervals are provided where they are most informative for interpretation—for example, in the analysis of static activities, where 95% confidence intervals are reported for posture-transition estimates (Section 3.5, lines 564–565). The experimental sample size and structure (24 cow–calf pairs allocated to six paddocks, three per treatment) are described in Section 2.2 (lines 98–103), and this design is linked to the performance results in Section 3.1 (lines 333–338). The number of paddocks and animals per paddock is also specified in the text and in the table captions, so readers can clearly identify n for each analysis Additionally, sample sizes (n) are clearly stated in every table and figure caption, showing that each treatment included three paddocks (n = 3 per treatment), each with four cow–calf pairs. These details ensure full transparency and consistency across all results, tables, and figures.

Data 2: Excessive precision is used while reporting certain p-values.

Response 2

We agree with the reviewer and have simplified p-value reporting throughout the manuscript. In the revised Results, p-values are now presented with consistent rounding to three decimal places (or as inequalities where appropriate) instead of long decimal strings. For example, in Section 3.1 (lines 325–336), p-values are reported as “p = 0.475”, “p < 0.050”, “p = 0.812”, and “p = 0.914,” and the same three-decimal convention has been applied across all other subsections of Section 3 and in the tables. This ensures a uniform and readable presentation of p-values without altering any statistical conclusions.

Data 3: Figures and tables provide useful information, but descriptions are too wordy.

Response 3

We appreciate the reviewer’s observation. However, the level of detail in figure legends and table captions was intentionally maintained to ensure transparency and interpretability of the results. Each description provides sufficient contextual and methodological information so that readers can understand the data without repeatedly referring back to the main text. This approach aligns with Sustainability’s author guidelines, which state that figure and table descriptions should be clear and complete so that readers can interpret them independently. Accordingly, we retained comprehensive explanations to keep figures and tables self-contained, facilitating independent interpretation and reproducibility of the results while maintaining clarity and consistency with MDPI standards. These clarifications are reflected in the revised text and captions associated with the main results (for example, Section 3.1, lines 325–338).

Data 4: Numerical differences must be summed up in conclusion and abstract without emphasizing trends that are not significant.

Response 4:

We agree with the reviewer and have revised the manuscript so that numerical, non-significant trends are clearly distinguished from statistically significant effects in both the Abstract and Conclusions. In the Abstract (line 24), we now state that average daily gain of calves was numerically greater in TT than in Ctrl and explicitly indicate that this difference was not statistically significant (p = 0.270). In the Results, Section 3.1 (lines 736–742) reiterates that there were no significant differences in calf ADG between treatments and notes that the relatively short 60-day duration may have limited the expression of performance responses. In this context, the term “trend” is used strictly in a descriptive, hypothesis-generating sense: it signals a numerical pattern that is consistent with the proposed mechanisms (improved nitrogen utilization and maternal nutrient partitioning) but does not constitute evidence of a statistically significant treatment effect within this 60-day trial. The Conclusions (Section 5.0, lines 894–896) therefore describe the higher ADG in TT calves as a numerical, non-significant difference (p = 0.270) and explicitly frame it as an observation that motivates future research with longer study durations and larger-scale evaluations, rather than as proof of a definitive performance response to tannin supplementation.

Comments on the Quality of English Language

Reviewer comment:
A comprehensive, expert language edit is advised to improve the text’s structure, clarity, and flow.

Response:
We appreciate this comment. The manuscript has been carefully revised to improve grammar, clarity, and overall readability. All changes are incorporated in the resubmitted version

Additional Clarifications

We thank the reviewer for recognizing the coherence of our experimental design and for the valuable feedback that strengthened our presentation. All updates and clarifications have been clearly marked in the revised manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Abstract:

Line 12 – which was your hypothesis? After reading all your abstracts I could not suppose which would be that.

Line 15 – which is the origin of this tannin?

Line 21-23 – This numerically difference is very small, and even a statistical tendency can not be considered, which could be used when P-value is near to 0.05, as example when P-values is equal to 0.09. So, this is not adequate.

Line 20 and 25 – distribution of what? This is the first time that the reader are in contact with the work.

Introduction:

Lines 31 – 34 – This is a regionalism. Then the authors must utilize an argumentation that could be accepted for any region worldwide.

Line 74 – How could the tannin chance the spatial distribution of the animals in the pasture? Which type of physiological modification this ingredient can made to reflect in the spatial distribution. This is not clear. A clearer hypothesis concerning this topic is required. Once establishing the cause and consequence from the obtained data would gain more scientific consistency. How the tannin would mimic the behavior in pasture. Maybe the relationship could be made from the intake, and so intake would drive this phenomenon? In which way?

Material and methods:

Line 98 – How much DDGs in the diet? Which is the nutritional composition? How about the chemical composition of the pasture? How much is the iNDF of this type of forage and the average expected intake? How much tannin? Once the authors have informed 0.4% (Line 117) tannin based on DGs, how about tannin in % of the diet?

Line 133: Which is the entry and exit height of this type of pasture?

Line 228-229: Which characterized each density category?

Line 258-259: Was water intake measured all days of the period? If not, how was this evaluation made? How many days?

Line 275: Was it fasting body weight? How many hours in fasting?

Line 280: In which samples did you make these analyses? DDG and pasture? How many samples per period? And how about the composite samples. Please provide the details. Why was NDF not made? The ADF obtained in no sequential method is not adequate.

Results:

Line 317 and 327: The P-value must be exhibited in Figure 1, as all figures must be auto explained in all their results. Also, the image quality of figure 1 is not good.

Line 351: The expression “strong effect” is not scientific. The effect exist (P<0.05) or not.

Line 357-358: Please remove this type of statement. There was no effect or tendency.

Table 4: The table was unconfigured. Where is the lignin values? I did not understand these DM? This is not from the fresh grass, maybe from the oven dried grass.

Figure 3: This figure is disproportional in vertical way.

Figure 5: There is no difference between treatments, maybe this figure could be reduced, because there is too much information that are very similar between them.

Table 5: In my opinion authors must take into account only the interactions between treatments with the other factors. Once the work of test all interactions are required, the slicing of all these factors is not mandatory. The manuscript are so long and many of this slicing concerning time is exhibited without any relevant study. It would be very useful if authors concentrate their results on the tannin results

Figure 7: This image is exclusively informative, and would be removed, once the manuscript is too large. There are ins no numerical information here.

Table 6: Is tannin effective in an isolate way in this variable? What are the P-values for this variable and their interactions?

Discussion:

The discussion must be reduced a lot and must be focused on the object of the study, which is the tannin. Separation in topics is not necessary and make reading easy.

Conclusion:

I could not see any advantage in tannin usage, once the behavior chance did not impact in performance, and this could add costs in the diet. The conclusion must be only some lines, now this topic is enormous, and he authors are trying to prove that tannins can be used even after all your evidence that difference is negligible. Please rewrite the conclusion.

Author Response

Response to Reviewer #2

Summary

We thank Reviewer 2 for the constructive feedback provided. The suggestions have helped us clarify the scope and strengthen the scientific presentation of our manuscript. All corresponding revisions are highlighted in the revised version of the paper, and detailed responses are provided below.

Reviewer Comment (Line 12): Which was your hypothesis?

Author Response:

We appreciate the reviewer’s question. In the revised manuscript, the hypothesis is stated explicitly in the Introduction. We explain that there is limited information on how supplemental tannins influence grazing behavior, spatial distribution, and water intake of free-ranging cattle (lines 75–76), and then clearly present our hypothesis that supplementing cattle with a commercial tannin extract would mimic some of the behavioral and nutritional functions of diverse phytochemical-containing forages via post-ingestive feedback and rumen nitrogen dynamics (lines 84–87). We then specify that, to test this hypothesis, we evaluated the effects of supplemental tannins on performance, grazing behavior, spatial distribution, and water consumption (lines 87–89). Keeping the hypothesis in the Introduction rather than the Abstract allows us to present it in full mechanistic and conceptual context, while the Abstract remains concise and focused on key results and implications.

Reviewer Comment (Line 15): Which is the origin of this tannin?

Author Response:

We thank the reviewer for this comment. The source and composition of the tannin supplement are clearly described in the Materials and Methods. In Section 2.2 (Animal and grazing protocol, lines 108–113), we specify that TT cattle received the same DDG supplement as Ctrl, with the addition of a tannin extract blend in powder form (ByPro, Silvafeed, Italy) mixed into the supplement, and that this blend consisted of one-third chestnut tannin extract and two-thirds quebracho tannin extract. Further details on the chemical composition of the quebracho extract are provided immediately afterward (lines 113–116). The Abstract is limited to 200 words according to MDPI formatting guidelines; therefore, this level of detail on tannin origin and composition is provided in the Methods rather than in the Abstract to avoid exceeding the word limit.

Reviewer Comment (Lines 21–23):

“This numerical difference is very small, and even a statistical tendency cannot be considered, which could be used when P-value is near to 0.05 (e.g., 0.09). So, this is not adequate.”

Author Response:

We understand the reviewer’s concern and agree that this difference cannot be interpreted as a tendency or effect. In the revised manuscript, we are careful not to present it as such. In the Abstract (lines 22–23), we now state that average daily gain of calves was numerically greater in TT than in Ctrl (1.03 vs. 0.93 kg/day) and explicitly indicate that this difference was not statistically significant (p = 0.270), without using terms such as “trend” or “tendency.” This clarification is consistent throughout the manuscript. In the Results (Section 3.1, lines 383-388), we reiterate that calf ADG did not differ significantly between treatments and note that the 60-day duration may have limited the expression of performance responses. The magnitude of the numerical difference (≈0.10 kg/day; 1.03 vs. 0.93 kg/day) would correspond to roughly 6 kg additional live weight over a 60-day grazing period, which is potentially relevant in beef production from a practical standpoint; however, because this difference was not statistically significant, we present it only as descriptive information. In the Conclusions (Section 5.0, lines 905–907), we therefore describe the higher ADG in TT calves strictly as a numerical, non-significant difference (p = 0.270) and use it only as a hypothesis-generating observation motivating future, longer-term studies, not as evidence of a tendency or confirmed treatment effect.

Reviewer Comment (Lines 20 and 25):

“Distribution of what? This is the first time that the reader is in contact with the work.”

Author Response:

We appreciate this clarification. In the revised manuscript, we made explicit that the term refers to spatial grazing distribution. In the Abstract, we added the word “spatial” so that the sentence now refers to spatial grazing distribution rather than simply “distribution,” making clear that we are describing how cattle use space across the paddocks. In the main text, this concept is further developed in the section on animal distribution (Section 3.7), where spatial distribution is quantified using the coefficient of variation (CV) of cattle locations across the paddock grid.

Reviewer Comment (Lines 31–34):

“This is a regionalism. The authors must utilize an argumentation that could be accepted for any region worldwide.”

Author Response:

We appreciate this suggestion and revised the Introduction to frame the study region within a global rangeland context rather than as a purely local or regional case. In the first paragraph of the Introduction, we now state that “Rangelands in the western United States are part of the world’s most extensive terrestrial ecosystems, which collectively cover 40–50% of the Earth’s land surface” and that, in the western U.S., these rangelands cover ~31% of the national land area and are fundamental for livestock production, supporting about eight million beef calves annually (Introduction, lines 37–38). By explicitly linking western U.S. rangelands to the global rangeland biome and emphasizing their contribution to world livestock production, the argumentation is no longer restricted to a single region but is embedded within the broader global significance and challenges of rangeland ecosystems

Reviewer Comment (Line 74):

How could the tannin change the spatial distribution of the animals in the pasture? Which type of physiological modification can this ingredient make to reflect in the spatial distribution? This is not clear. A clearer hypothesis concerning this topic is required. Once establishing the cause and consequence from the obtained data, the study would gain more scientific consistency. How would the tannin mimic behavior in pasture? Maybe the relationship could be made from intake, and so intake would drive this phenomenon? In which way?

Author Response:

We thank the reviewer for this insightful comment. In the revised manuscript, we clarified both the hypothesis and the mechanistic pathway linking tannin supplementation to spatial grazing distribution. In the Introduction, we now state explicitly that we hypothesized that supplementing cattle with a commercial tannin extract would mimic some of the behavioral and nutritional functions of grazing diverse phytochemical-containing forages, by modifying post-ingestive feedback, rumen nitrogen dynamics, and water use, and thereby influencing grazing behavior and spatial distribution across the paddock (Introduction, lines 75–81). This mechanistic pathway is further developed in the Discussion. Section 4.4 (lines 770–772 and 776–789) explains that tannin supplementation reduces blood urea nitrogen (BUN), stabilizes rumen nitrogen, and improves microbial efficiency, which in turn alters post-ingestive feedback and delays satiety. These physiological changes are linked to the observed behavioral adjustments, namely increased evening grazing, reduced evening rumination, and use of cooler periods with higher forage quality. Section 4.5 (lines 792–802 and 815–819) then connects these behavioral shifts to spatial grazing patterns, showing that tannin-supplemented cows used the paddocks more uniformly and reduced overuse of specific patches. In this framework, intake and post-ingestive feedback are explicitly treated as the causal link between tannin supplementation, altered foraging behavior, and the resulting spatial distribution, thereby addressing the cause–consequence relationship highlighted by the reviewer.

Reviewer 2 – Line 98 comment

“How much DDGs in the diet? Which is the nutritional composition? The authors indicate they used (line 117) tannin based on DGs, how about tannin in % of the diet?”

Author Response:

We thank the reviewer for this valuable comment. In the revised manuscript, we clarify both the feeding rate of DDGs and the analytical information for DDGs and pasture. In Section 2.2 (Animal and grazing protocol, lines 108–113), we now state that each cow received 1 kg of DDGs per day, and that TT animals received the same DDG base plus 400 g of the tannin blend added daily to 1 kg of DDGs per cow, specifying the inclusion level of tannin in the supplement. The same section specifies that the tannin blend consisted of one-third chestnut and two-thirds quebracho extract (lines 100–103), making the origin and proportion of the tannin source explicit. The nutritional composition of DDGs and pasture (including dry matter, crude protein, neutral detergent fiber, acid detergent fiber, lignin, ether extract, and ash) is described in the Chemical Analyses section (Section 2.4, lines 294–298) and summarized in Table 1. In addition, we clarify in Section 2.2 (lines 137–138) that, although the main fiber fractions were analyzed, indigestible NDF (iNDF) was not analyzed in this study.

Reviewer comment Line 133 – “Which is the entry and exit height of this type of pasture?”
Response: Change made: Added the explanation in Section 2.3.1 at lines 145–146 clarifying that no fixed entry/exit sward heights were used because the meadow bromegrass monoculture was structurally uniform. We also indicate where biomass measurements are described: pre-grazing herbage biomass at lines 143–145, and post-grazing biomass obtained using a rising plate pasture meter at lines 148–151.

Reviewer Comment (Lines 228–229) “Which characterized each density category?”

Author response: We appreciate this comment. In the revised manuscript, we explicitly define how each grazing-density category is characterized in Section 2.3.3 (Grazing Distribution). Specifically, lines 235–238 state that grid values represent the number of grazing visits per m² (line 235) and that density outputs were classified into five categories (lines 236–238): no grazing (0), light (0.1–1.5), moderate (1.6–3.0), heavy (3.1–4.5), and very heavy (4.6–6.0).

Reviewer Comment (Lines 258–259):

Was water intake measured all days of the period? If not, how was this evaluation made? How many days?
Author Response:

We thank the reviewer for this question. In Section 2.3.5 (Water Consumption Estimates) we clarify that water intake was measured every day during a 38-day mid-summer period (29 July–5 September 2024; lines 265–268). Two ~380 L troughs (135 × 79 × 64 cm) were filled each morning; remaining depth was measured before refilling, and depth (cm) was converted to volume (L) from trough dimensions, with daily records including date, paddock type and number, water depth, remaining water, estimated consumption, and notes on weather and animal behavior (lines 269–274). To correct for evaporative loss, a control trough outside the paddock (no animal access) was monitored under the same protocol, and animal water intake was calculated as filled volume minus remaining volume, adjusted by evaporative loss from the control (lines 275–279).

Reviewer Comment (Line 280):

In which samples did you make these analyses? DDG and pasture? How many samples per period? And how about the composite samples. Please provide the details. Why was NDF not made? The ADF obtained in no sequential method is not adequate.

Author response:

We thank the reviewer for this detailed comment. In Section 2.2, we specify that 10 g of DDGs were collected daily during supplementation and composited by period for chemical analyses (lines 132–134); grazing was conducted in four 15-day periods, so each composite comprised daily subsamples across a 15-day period (lines 128–129). For pasture, Section 2.3.1 describes pre- and post-grazing sampling at the paddock level: 150 plate-meter readings per paddock per event (lines 148–151) and ten clipped quadrats per paddock per event (lines 153–154), which were dried, ground (1-mm) and used to calibrate plate-meter estimates and for forage-quality analyses (lines 155–161, 169–170). Analytical procedures for DM, CP, ADF, and NDF are detailed in Section 2.4: DM and N per AOAC 930.04/990.03 (lines 294–299), ADF per AOAC 973.18 (line 300), and NDF following Robertson & Van Soest with a filtration modification (lines 301–303). To address the question about NDF: NDF was measured (Section 2.4, lines 294–296); only indigestible NDF (iNDF) was not determined (Section 2.3.1, lines 137–138).

Reviewer Comment (Lines 317 and 327):

The P-value must be exhibited in Figure 1, as all figures must be auto-explained in all their results. Also, the image quality of Figure 1 is not good.

Author Response:

We thank the reviewer for this comment. Figure 1 is intended to illustrate the seasonal summer decline in meadow bromegrass biomass across periods and years for both treatment groups, rather than to emphasize a significant difference in biomass removal between treatments. In the Results, we explicitly report that biomass removal did not differ between tannin-supplemented and control cows (p = 0.475) and that there was a significant decline in available biomass across periods (p < 0.05) for both years (Section 3.1, lines 333–335). We also quantify the reduction in biomass from Period 1 to Period 4 and the decline between 2023 and 2024 (lines 336–338), which is the temporal pattern reflected in Figure 1. This significant seasonal decline in forage availability is central to the study because it captures the biophysical context in which protein and tannin supplementation become most relevant, i.e., late summer, when pasture quantity and quality decrease and strategic supplementation is typically required. To improve readability, we kept Figure 1 as a graphical summary of these temporal dynamics and retained the full P-values in the Results text and associated tables, rather than placing all statistics directly on the figure. The image quality of Figure 1 has also been improved in the revised manuscript by exporting the graph at higher resolution (1200 dpi) with enhanced contrast and standardized axis labels and fonts (Figure 1 caption, line 352).

Reviewer Comment (Lines 357–358):

Please remove this type of statement. There was no effect or tendency.

Author Response:

Was removed in line 369.

Reviewer Comment (Table 4):

The table was unconfigured. Where is the lignin values? I did not understand these DM? This is not from the fresh grass, maybe from the oven dried grass.

Author Response:

Table 4 was corrected to Table 1 in the revised version. The table was properly formatted and presents neutral detergent fiber (NDF) rather than lignin, consistent with the fiber fractions analyzed and described in the Chemical Analyses section. The DM values represent oven-dried herbage samples collected during the summer grazing period, when the grass was naturally dry, to capture forage removal dynamics across periods and treatments.

Reviewer Comment (Figure 3):

This figure is disproportional in vertical way.

Author Response:

We appreciate the reviewer’s observation. Figure 3 has been reformatted to correct its vertical proportions, ensuring uniform axis scaling, balanced spacing, and improved visual clarity in the revised manuscript.

Reviewer Comment (Figure 5):

There is no difference between treatments, maybe this figure could be reduced, because there is too much information that are very similar between them.

Author Response:

We thank the reviewer for this observation. Figure 5 has been removed as suggested to streamline the manuscript and avoid redundancy, since treatment differences were minimal and similar patterns were already represented in other figures.

Reviewer Comment (Figure 7):

This image is exclusively informative and should be removed, as the manuscript is already too large. There is no numerical information here.

Author Response:

We appreciate the reviewer’s suggestion. Figure 7 ( currently rename figure 6) has been retained because it provides essential spatial context for understanding the distribution of grazing intensity across paddocks and treatments. While it is a qualitative visualization, it complements the quantitative data presented in Table 6 by visually depicting the spatial heterogeneity and treatment-related shifts in grazing use. Spatial representation is critical in grazing ecology to illustrate how behavior and landscape use interact under treatment effects information that cannot be conveyed by numerical tables alone.

Reviewer Comment (Table 6):

Is tannin effective in an isolate way in this variable? What are the P-values for this variable and their interactions?

Author Response:

We appreciate the reviewer’s insightful question. In this experiment, Period 1 served as a common baseline for both treatments (no tannin supplementation), while Periods 2–4 reflected the progressive response to tannin intake. Thus, treatment effects could only be expressed through the treatment × period interaction, since the influence of tannins emerged over time rather than as an immediate main effect. Statistical analyses using a mixed-effects model (treatment, period, and their interaction) revealed a significant treatment × period interaction, indicating that tannin effects became evident in later periods, particularly in Period 4 when animals were fully adapted. To quantify this final effect, an independent t-test comparing TT and Ctrl paddocks in Period 4 showed that TT paddocks had a lower coefficient of variation (CV) (1.86 vs. 2.13 in Ctrl; p = 0.0426; Table 3 ), reflecting a more uniform spatial grazing pattern ( Line 608-610). This approach captures the biological reality of a progressive adaptation to tannins under free-grazing conditions, where the treatment effect is best interpreted through its interaction with time.

Reviewer Comment (Discussion):

The discussion must be reduced a lot and must be focused on the object of the study, which is the tannin. Separation in topics is not necessary and make reading easy.

Author Response:

We appreciate the reviewer’s perspective. In the revised manuscript, we carefully reviewed the Discussion and removed repeated or tangential sentences to improve focus and flow, particularly where similar ideas appeared in more than one subsection. However, we kept the thematic subheadings because they mirror the structure of the Results and help readers follow how tannin supplementation affects each response variable (water intake, performance, foraging behavior, spatial distribution, etc.) in a logical sequence. Each subsection of the Discussion is now explicitly linked back to the effects of tannins and to the central hypothesis (tannin-mediated changes in post-ingestive feedback, nitrogen dynamics, behavior, and spatial use of pasture). This structure allows us to interpret the main findings in an integrated way without duplicating the Results section, while still keeping tannin effects as the central focus throughout.

Reviewer Comment (Conclusion):

“I could not see any advantage in tannin usage, once the behavior change did not impact performance, and this could add costs in the diet. The conclusion must be only some lines, as the authors are trying to prove that tannins can be used even after all evidence that the difference is negligible. Please rewrite the conclusion.”

Author Response:

We appreciate the reviewer’s critical evaluation. While direct performance effects (e.g., body weight gain) were not significant, the study revealed meaningful behavioral and spatial adaptations linked to tannin supplementation, including longer evening grazing periods, fewer standing-to-lying transitions, and more uniform grazing distribution. These responses are not trivial; they indicate physiological and ruminal adjustments consistent with improved nitrogen utilization and post-ingestive feedback, aligning with our original hypothesis. Even without short-term performance gains, such behavioral and spatial modifications are ecologically relevant because they reduce grazing pressure heterogeneity, minimize overuse of preferred patches, and support long-term pasture sustainability. Thus, the study demonstrates that tannins act as functional bioactive compounds influencing animal behavior and rangeland use patterns—an important contribution to sustainable grazing systems. In response to the reviewer’s suggestion, the conclusion has been condensed for clarity and focus, emphasizing the physiological and ecological implications rather than promoting tannin use solely for production outcomes.

Additional Clarifications

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors

Bashiri Iddy Muzzo et al in this work investigated how tannin supplementation influences the behavior and performance of beef cattle grazing a meadow bromegrass monoculture. Animals with TT receiving an added 0.4% tannins. The results indicated that tannin extended evening grazing, reduced rumination, and promoted even distribution, indicative of increased forage selectivity. The data is interesting and encouraging, and certainly suitable for publication. However, a number of queries have arisen during my review, which I list below for the authors to consider.

How is the dosage of tannin added in DGGs determined？

Author Response

Reviewer 3

Summary

We thank Reviewer 3 for the constructive feedback provided. The suggestions have helped us clarify the scope and strengthen the scientific presentation of our manuscript. All corresponding revisions are highlighted in the revised version of the paper, and detailed responses are provided below.

Reviewer Comment:

How is the dosage of tannin added in DDGs determined?

Author Response:

We thank the reviewer for this important question. In the revised manuscript, we clarify the level and context of tannin inclusion in the Methods. In Section 2.2, we state that cows in both treatments received 1 kg/cow/day of DDGs and that TT cows received the same DDG supplement with the addition of a tannin blend that represented approximately 0.4% of the diet (400 g of tannin blend added daily to 1 kg of DDGs/cow) (Section 2.2, lines 133–135). This 0.4% dietary level was chosen as a moderate inclusion rate that is compatible with free-grazing beef systems high enough to modulate nitrogen dynamics and behavior, but low enough to avoid negative effects on intake or general activity.

Additional Clarifications

All updates and clarifications have been clearly marked in the revised manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

General comments: The manuscript investigates how tannin supplementation affects foraging behavior, spatial distribution, and performance of beef cattle grazing in meadow bromegrass monocultures. The research is methodologically robust and presents an innovative integration of behavioral ecology, animal nutrition, and rangeland management. The experimental design is solid, with adequate replication and appropriate use of GPS collars and accelerometers for behavioral analysis. Statistical modeling is well detailed, and the authors effectively integrate mixed models with machine learning-based behavioral predictions, which represents an interesting methodological advancement for animal behavior studies. Despite these merits, the manuscript is excessively long and contains redundant information in several sections, especially in the Introduction and Materials and Methods. The text often repeats ideas and includes technical details that could be summarized or moved to supplementary material. The writing requires careful revision for clarity and conciseness, as there are grammatical inconsistencies, awkward phrasing, and variable use of terminology. The Discussion, while rich in references, sometimes reiterates results rather than deepening interpretation, and it overstates some findings where statistical support is weak. For instance, the manuscript attributes biological significance to non-significant trends, particularly regarding calf average daily gain and evening grazing time. The conclusion could also be more succinct and emphasize practical implications rather than numerical repetition. Overall, this is a relevant and innovative study that contributes to understanding how phytochemical supplementation may modulate grazing dynamics and welfare indicators in cattle, but it needs substantial language and structural revision to enhance its scientific impact.

Specific comments:
Abstract: The abstract clearly outlines the study’s objectives, methodology, and main findings, but it is overloaded with quantitative details that obscure the broader significance of the results. The authors should focus on highlighting the main behavioral and physiological outcomes, such as increased evening grazing time, more uniform grazing distribution, and higher water intake, while minimizing excessive statistical data. Claims regarding improved welfare and selectivity should be made more cautiously and supported by stronger evidence. A more concise and impactful summary would better communicate the study’s relevance to sustainable livestock management.

Introduction: The introduction provides a thorough contextualization of the role of tannins in ruminant nutrition and ecosystem function. It successfully establishes the relevance of the topic within the broader framework of sustainable livestock production. However, the section is unnecessarily long and repetitive, particularly when discussing the biochemical properties and ecological effects of tannins. Several paragraphs reiterate similar points about protein utilization and methane mitigation. The logical flow between background information, knowledge gaps, and research hypotheses should be improved. The hypothesis itself, stating that tannin supplementation might mimic the functional diversity of phytochemically rich forages, is compelling, but it should be more explicitly linked to the specific behavioral and physiological mechanisms being tested. A more concise and direct presentation would strengthen the section’s focus and readability.

Materials and Methods: This section is technically detailed and demonstrates careful planning and execution of the experiment. The design, involving 24 cow–calf pairs distributed across six paddocks and evaluated over two years, provides adequate replication. The use of both GPS collars and pedometers to capture foraging and activity data adds methodological robustness. However, the level of detail is excessive, with descriptions of technical steps, such as coordinate projections, calibration equations, and model training procedures, that could be condensed or moved to supplementary materials. The statistical analysis section is particularly dense, and it should be rewritten to clearly describe the mixed-model structure, random effects, and repeated measures. Some abbreviations appear abruptly without definition, and the explanation of machine learning validation from previous studies could be shortened. Overall, the section would benefit from a more streamlined narrative focusing on experimental logic rather than technical minutiae.

Results: The results are comprehensive and supported by a wide range of measurements, from biomass and nutritional composition to spatial distribution and behavior. The figures and tables are clear, although their number could be reduced to avoid redundancy. While the statistical outcomes are appropriately presented, the narrative often blurs the distinction between data description and interpretation. Several results are reported with unnecessary precision or described as “trends” despite being non-significant, which should be avoided. The presentation would benefit from summarizing patterns rather than restating full statistical outputs. For example, emphasizing that tannin supplementation did not affect biomass removal or weight loss but led to greater water consumption and longer evening grazing would make the findings clearer and more digestible. The results section overall provides strong empirical evidence, but it requires condensation and clearer focus on biologically meaningful effects.

Discussion: The discussion interprets the findings within an appropriate theoretical framework and includes a solid review of relevant literature on tannin metabolism and animal foraging ecology. However, the text is too long and occasionally repetitive, revisiting points already mentioned in the Introduction. The interpretation of behavioral changes, such as extended evening grazing and fewer standing-to-lying transitions, is coherent, but the link between these behaviors and improved welfare or selectivity should be made cautiously, as physiological indicators are not directly measured. The discussion could also benefit from deeper exploration of ecological implications, such as how altered grazing patterns might influence pasture heterogeneity, nutrient cycling, and rangeland sustainability. Furthermore, a critical paragraph acknowledging the study’s limitations, such as sample size, single geographic location, potential weather effects, and lack of physiological measurements, would strengthen scientific transparency. Shortening this section and enhancing interpretive depth would make the conclusions more persuasive.

Conclusion: The conclusion effectively summarizes the main findings, emphasizing that tannin supplementation influenced foraging behavior and grazing distribution without compromising performance. However, it could be written in a more concise and impactful manner by avoiding numerical repetition and focusing on key insights: tannins promoted more even grazing, extended evening activity, and increased water intake, suggesting adaptive physiological adjustments. The practical implications for ruminant management and environmental sustainability could be highlighted more explicitly, along with the need for further research to confirm long-term effects and optimal dosage under diverse rangeland conditions. Overall, a tighter and more focused conclusion would better reflect the study’s significance.

Comments on the Quality of English Language

The manuscript requires substantial revision of the English language. While the scientific content is strong and the terminology appropriate, the text contains numerous grammatical errors, awkward sentence constructions, and repetitive phrasing. The overall readability is affected by overly long sentences and inconsistent use of tenses and connectors. A thorough professional language edit is recommended to improve fluency, coherence, and conciseness throughout the manuscript.

Author Response

Response to Reviewer #4

Summary

We thank Reviewer 4 for the constructive feedback provided. The suggestions have helped us clarify the scope and strengthen the scientific presentation of our manuscript. All corresponding revisions are highlighted in the revised version of the paper, and detailed responses are provided below.

Comments and Suggestions for Authors

Author Response:

We thank the reviewer for recognizing the scientific rigor and innovation of this work. The detailed Materials and Methods are essential rather than redundant, as each subsection (foraging behavior, activity, water intake, and spatial distribution) maintains clear connections between measured variables, sensor data, and subsequent mixed-model or GIS analyses. Condensing these components into a single section would obscure methodological logic and limit reproducibility. To improve conciseness, supplementary materials (e.g., Tables A1–A2 describing calibration and model validation) were moved to the appendix, reducing length while maintaining transparency and scientific integrity. While some results were not statistically significant, they remain biologically meaningful in free-grazing systems where behavioral responses to phytochemicals develop gradually. For example, tannin supplementation did not alter forage removal or body weight (p > 0.05) but produced consistent directional effects on evening grazing, water intake, activity transitions, and spatial distribution, reflecting physiological adjustments to secondary compound ingestion. These outcomes highlight how tannins influence post-ingestive feedback, nitrogen metabolism, and grazing efficiency without compromising animal performance. Maintaining methodological detail was necessary to ensure clarity, reproducibility, and interpretability for future applications in grazing ecology. The manuscript has been refined in several parts of the Discussion and overall Conclusion to improve conciseness, strengthen focus on tannin-related findings, and enhance readability while preserving scientific depth and accuracy.

Specific comments:

Abstract: The abstract clearly outlines the study’s objectives, methodology, and main findings, but it is overloaded with quantitative details that obscure the broader significance of the results. The authors should focus on highlighting the main behavioral and physiological outcomes, such as increased evening grazing time, more uniform grazing distribution, and higher water intake, while minimizing excessive statistical data. Claims regarding improved welfare and selectivity should be made more cautiously and supported by stronger evidence. A more concise and impactful summary would better communicate the study’s relevance to sustainable livestock management.

Author Response:

While we recognize the importance of concise abstracts, reporting quantitative and statistical outcomes is standard in animal nutrition and behavior studies as it provides the necessary context for interpreting treatment effects with scientific accuracy. The inclusion of key p-values and mean differences allows transparent evaluation of effect magnitude and direction, which is critical in behavioral ecology research. We emphasize that the manuscript does not claim direct improvements in welfare or selectivity. Rather, these outcomes were interpreted as behavioral indicators, for example reduced standing-to-lying transitions and more even spatial grazing distribution, which are well-established proxies for animal comfort, stability, and foraging efficiency in the literature. These interpretations are presented within the Discussion, not as treatment claims, ensuring objectivity and scientific interpretability. Accordingly, the Abstract retains essential quantitative data while remaining focused on the major behavioral and physiological responses observed with tannin supplementation.

Introduction: The introduction provides a thorough contextualization of the role of tannins in ruminant nutrition and ecosystem function. It successfully establishes the relevance of the topic within the broader framework of sustainable livestock production. However, the section is unnecessarily long and repetitive, particularly when discussing the biochemical properties and ecological effects of tannins. Several paragraphs reiterate similar points about protein utilization and methane mitigation. The logical flow between background information, knowledge gaps, and research hypotheses should be improved. The hypothesis itself, stating that tannin supplementation might mimic the functional diversity of phytochemically rich forages, is compelling, but it should be more explicitly linked to the specific behavioral and physiological mechanisms being tested. A more concise and direct presentation would strengthen the section’s focus and readability.

Author Response

We appreciate this comment and have condensed and sharpened the Introduction while keeping the key mechanisms and gaps. In the revised version, we merged repetitive statements about tannins improving protein utilization and lowering methane into a single, concise passage (lines 44–56), and streamlined the mechanistic context on water intake, detoxification, and behavioral–physiological integration by retaining only the essential examples and references (lines 60–71). We also shortened the rationale for commercial tannin extracts to focus on their consistent quality, standardized dosage, and scalability relative to the more variable tannins found in natural forages (lines 74–79). The gap statement now directly targets how supplemental tannins influence grazing behavior, spatial distribution, and water intake of free-ranging cattle (lines 82–83), followed by an explicitly mechanistic hypothesis stating that a commercial tannin extract would mimic some of the behavioral and nutritional functions of diverse phytochemical-containing forages via post-ingestive feedback and rumen nitrogen dynamics (lines 84–86). Finally, we close the Introduction with a concise statement of the study’s aims, specifying that we evaluated the effects of tannin supplementation on animal performance, grazing behavior, spatial distribution, and water consumption (lines 86–89), thereby centering the narrative on the main research questions.

Materials and Methods: This section is technically detailed and demonstrates careful planning and execution of the experiment. The design, involving 24 cow–calf pairs distributed across six paddocks and evaluated over two years, provides adequate replication. The use of both GPS collars and pedometers to capture foraging and activity data adds methodological robustness. However, the level of detail is excessive, with descriptions of technical steps, such as coordinate projections, calibration equations, and model training procedures, that could be condensed or moved to supplementary materials. The statistical analysis section is particularly dense, and it should be rewritten to clearly describe the mixed-model structure, random effects, and repeated measures. Some abbreviations appear abruptly without definition, and the explanation of machine learning validation from previous studies could be shortened. Overall, the section would benefit from a more streamlined narrative focusing on experimental logic rather than technical minutiae.

Author Response:

n the revised manuscript, we removed some narrative repetition and non-essential descriptions to improve readability, while carefully retaining the methodological detail required for full reproducibility. The journal’s Instructions for Authors state that Materials and Methods “should be described with sufficient detail to allow others to replicate and build on published results”, and that new methods and protocols should be described in detail rather than only cited, and full experimental details must be provided so that results can be reproduced. For example, we shortened some narrative descriptions and removed minor repetitions so that the main text now focuses on the experimental design (Section 2.2, lines 106–127), herbage and animal measurements (Sections 2.3.1–2.3.5, lines 143–171, 216–242, 244–279), chemical analyses (Section 2.4, lines 293–303), and the core structure of the mixed-effects models (Section 2.5, lines 305–324). In this context, we kept the full description of the accelerometer and GPS setup, the machine-learning workflow used to classify behaviors from sensor data, and the associated accuracy, sensitivity, and specificity metrics, because these steps are critical for correctly differentiating behavioral states and for allowing other researchers to reproduce or reuse our approach under free-grazing conditions. Thus, while some text was streamlined, the section still provides the level of methodological detail expected by Sustainability, balancing methodological transparency with a more concise and focused presentation.

Results: The results are comprehensive and supported by a wide range of measurements, from biomass and nutritional composition to spatial distribution and behavior. The figures and tables are clear, although their number could be reduced to avoid redundancy. While the statistical outcomes are appropriately presented, the narrative often blurs the distinction between data description and interpretation. Several results are reported with unnecessary precision or described as “trends” despite being non-significant, which should be avoided. The presentation would benefit from summarizing patterns rather than restating full statistical outputs. For example, emphasizing that tannin supplementation did not affect biomass removal or weight loss but led to greater water consumption and longer evening grazing would make the findings clearer and more digestible. The results section overall provides strong empirical evidence, but it requires condensation and clearer focus on biologically meaningful effects.

Response to Reviewer – Results Section (Lines 336–606)

We appreciate the reviewer’s suggestion to condense the Results section and to emphasize biologically meaningful effects. In the revised manuscript, we carefully reviewed the necessary Results subsection (Sections 3.1–3.7). We removed redundant phrases, repeated statistics, and overly detailed descriptions that did not alter the interpretation while providing a concise summary of the research findings. For example, Section 3.3 (Distance travelled, lines 410–414) emphasizes that distance walked did not differ between treatments and that the main differences were associated with time of day and period. Section 3.4 (Impact of tannin on states and foraging activities, lines 463–466) reports only the key result that activity states did not differ between treatments, while summarizing overall daily active time. Section 3.5 (Impact of tannins on foraging behavior when discriminating static activities, lines 534–538) similarly presents the non-significant treatment effects on resting and rumination in a more compact form, focusing on the intense period and time-of-day effects. Finally, Section 3.7 (Animal distribution, lines 606–612) has been edited to highlight the lower coefficient of variation in TT paddocks and the resulting more even grazing distribution, without repeating background explanations already given in the Methods and Discussion. These changes make the Results more concise while retaining all statistically and biologically important findings.

Discussion: The discussion interprets the findings within an appropriate theoretical framework and includes a solid review of relevant literature on tannin metabolism and animal foraging ecology. However, the text is too long and occasionally repetitive, revisiting points already mentioned in the Introduction. The interpretation of behavioral changes, such as extended evening grazing and fewer standing-to-lying transitions, is coherent, but the link between these behaviors and improved welfare or selectivity should be made cautiously, as physiological indicators are not directly measured. The discussion could also benefit from deeper exploration of ecological implications, such as how altered grazing patterns might influence pasture heterogeneity, nutrient cycling, and rangeland sustainability. Furthermore, a critical paragraph acknowledging the study’s limitations, such as sample size, single geographic location, potential weather effects, and lack of physiological measurements, would strengthen scientific transparency. Shortening this section and enhancing interpretive depth would make the conclusions more persuasive.

Author Response:

We thank the reviewer for their thoughtful and constructive feedback on the Discussion section. In response, we revised this section (lines 645 to 896) to improve focus, clarity, and interpretive depth. Repetitive background information overlapping with the Introduction, particularly general descriptions of tannin metabolism and plant secondary compounds in the opening paragraphs of the Discussion, was condensed to keep the emphasis on interpreting our study’s findings relative to our hypotheses. The interpretation of behavioral changes, such as extended evening grazing and fewer posture transitions, was rephrased to ensure scientific caution. Specifically, we now state that these behaviors may indicate improved comfort or metabolic stability but do not confirm welfare benefits without supporting physiological evidence. While fewer standing to lying transitions can be consistent with improved comfort or metabolic stability, we refrain from inferring welfare outcomes here because no physiological or rumen fermentation indicators were collected in this trial; these are outlined as priorities in the Limitations (Section 4.7). The relevant interpretation is now consolidated in lines 841 to 866. We also expanded the discussion of ecological implications (lines 810 to 837) to provide greater depth on how tannin supplementation, by promoting more uniform grazing distribution, can enhance pasture heterogeneity, nutrient cycling, and rangeland resilience. These additions link the observed behavioral shifts to potential improvements in pasture recovery and nutrient balance, especially in monoculture systems where diversity is limited. Because TT paddocks showed a lower coefficient of variation in grazing intensity by Period 4 (CV 1.861 vs. 2.13; p = 0.043), tannin-linked behavioral shifts plausibly reduce patch overuse and promote more even pasture use, mechanisms that can enhance heterogeneity, support nutrient cycling, and build rangeland resilience in monoculture contexts. Furthermore, we added a new subsection titled “4.7. Study Limitations and Future Directions” (lines 869 to 894) that explicitly acknowledges key constraints of the study, including the limited sample size, short duration, single location, potential mid-summer weather effects, and the lack of physiological or rumen fermentation measures. This section also outlines future directions involving the integration of physiological, metabolomic, and multi-sensor behavioral tools to validate the proposed mechanisms and assess the broader ecological and management relevance of tannin supplementation.

Conclusion: The conclusion effectively summarizes the main findings, emphasizing that tannin supplementation influenced foraging behavior and grazing distribution without compromising performance. However, it could be written in a more concise and impactful manner by avoiding numerical repetition and focusing on key insights: tannins promoted more even grazing, extended evening activity, and increased water intake, suggesting adaptive physiological adjustments. The practical implications for ruminant management and environmental sustainability could be highlighted more explicitly, along with the need for further research to confirm long-term effects and optimal dosage under diverse rangeland conditions. Overall, a tighter and more focused conclusion would better reflect the study’s significance.

Author Response

We appreciate the reviewer’s suggestion to make the Conclusion more concise and impact focused. Accordingly, we rewrote the Conclusion lines 897–917 to remove numerical repetition and leave p values, emphasize the key insights of more even grazing, extended evening activity, and increased water intake, and to foreground practical implications for grazing management and environmental sustainability. We also aligned the tone with the Discussion by avoiding definitive welfare claims and explicitly noting that physiological and rumen fermentation measures were not collected in this trial. Finally, we clarified the call for future research to address long term effects, optimal dosage across contrasting rangelands, and economic feasibility while integrating physiological, metabolomic, and ecological endpoints. This revision yields a tighter and more management relevant Conclusion that better reflects the study’s significance.

Comments on the Quality of English Language

Author Response:

We thank the reviewer for this valuable observation regarding the English language quality. We have carefully revised the entire manuscript to improve grammar, sentence structure, and readability. All sections were edited for consistency in tense, connector usage, and scientific tone, and overly long or repetitive sentences were condensed to enhance clarity and flow.

Additional Clarifications

Reviewer 5 Report

Comments and Suggestions for Authors

General comment

Authors investigated how tannin supplementation influences the behavior and performance of beef cattle grazing a meadow bromegrass monoculture. It is a very interesting study and can be accepted after a major revision.

Specific comments

The 2.1-2.3 parts need more details regarding this experiment.

The figure presentation style is not good. I suggest to change all of them and make them more obvious.

The table and figure sequences have some problems. Revise them.

Show the P values for tables.

Figure 2 is very unclear. Change it.

L885 The conclusion section is too long! Just use 3-5 sentences. Also give some insights for the future studies.

Author Response

Reviewer #5 – General and Specific Comments

Summary

We thank Reviewer 5 for the constructive feedback provided. The suggestions have helped us clarify the scope and strengthen the scientific presentation of our manuscript. All corresponding revisions are highlighted in the revised version of the paper, and detailed responses are provided below.

General Comment:
Authors investigated how tannin supplementation influences the behavior and performance of beef cattle grazing a meadow bromegrass monoculture. It is a very interesting study and can be accepted after a major revision.

Author Response:
We sincerely thank Reviewer #5 for recognizing the scientific value of our work and for the constructive feedback that helped us strengthen the manuscript. We have addressed all comments carefully as outlined below.

Specific Comments and Responses

Comment 1. The 2.1–2.3 parts need more details regarding this experiment.
Response. We expanded Sections 2.1–2.3 to improve transparency and reproducibility. Added details include site description and management (Section 2.1, starting around line 91), animal allocation and paddock setup (Section 2.2, starting around line 105), and complete sampling and measurement protocols (Section 2.3, starting around line 141), including herbage availability (2.3.1, line 142), foraging behavior (2.3.2, line 173), and grazing distribution (2.3.3, line 216).

Comment 2. The figure presentation style is not good. I suggest to change all of them and make them more obvious.
Response. All figures were redesigned for clarity and consistency: enhanced contrast, standardized fonts and label hierarchy, simplified legends, uniform axis treatments, and concise captions to aid interpretation.

Comment 3. The table and figure sequences have some problems. Revise them.
Response. We corrected all numbering and ordering so that each table and figure now appears in the same sequence in which it is first cited in the text. We also rechecked cross-references in Results and Discussion to ensure accuracy.

Comment 4. Show the P values for tables.
Response. We added P values to all relevant tables, including Table 1 and Table 2, and harmonized the notes beneath each table to explain model terms and multiple-comparison adjustments where applicable.

Comment 5. Figure 2 is very unclear. Change it.
Response. Figure 2 was completely redesigned with simplified color coding, clearer legends, higher contrast, and refined axis labels and captioning to improve readability and interpretation.

comment 6. L885 The conclusion section is too long! Just use 3–5 sentences. Also give some insights for the future studies.
Response. The Conclusion was rewritten and condensed. Also, It emphasizes key insights (more even grazing, extended evening activity, increased water intake without performance loss), explicitly notes the need for physiological confirmation, and highlights practical implications and future research priorities.

Additional Clarifications

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has greatly improved, with better data presentation, a more precise connection between findings and conclusions, and a clearer organization. Although the English language has improved, some editing is still necessary to ensure flow and clarity. Overall, the work is sound from a scientific standpoint and may be published with a few minor language corrections.

Reviewer 4 Report

Comments and Suggestions for Authors

All the suggestions have been fully addressed by the authors, and I consider the manuscript ready for publication.