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Article

Comparison of Contemporary Grazing Cattle and Bison Greenhouse Gas Emissions in the Southern Great Plains

by
Maria De Bernardi
1,
Carlee M. Salisbury
1,
Haley E. Larson
2,
Matthew R. Beck
3 and
Logan R. Thompson
1,*
1
Department of Animal Science and Industry, Kansas State University, Manhattan, KS 66506, USA
2
Kansas State University-Olathe, Olathe, KS 66061, USA
3
Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
*
Author to whom correspondence should be addressed.
Ruminants 2025, 5(3), 34; https://doi.org/10.3390/ruminants5030034 (registering DOI)
Submission received: 5 June 2025 / Revised: 14 July 2025 / Accepted: 25 July 2025 / Published: 28 July 2025
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Simple Summary

Land use has changed dramatically over recent centuries, with a considerable amount of land being dedicated to livestock production. This expansion of land resources dedicated to livestock has come at the expense of natural systems, and there are discussions around the best use of grazing resources moving forward. This paper examines the difference between the greenhouse gas emissions from cow–calf production, stocker cattle production, and bison grazing, both modern and historic, on native prairie rangelands. We found that beef production systems generated less greenhouse gas emissions during their grazing seasons compared to modern bison grazing, but historic bison grazing produced slightly lower emissions than beef production. This implies that, compared to a natural baseline, emissions from modern beef production in this prairie ecosystem are similar to what may have been produced prior to livestock expansion; therefore, discussions on the uses of rangelands should be focused on ecological outcomes rather than emission avoidance.

Abstract

The objective of this analysis was to compare the greenhouse gas (GHG) emissions from contemporary grazing cattle production with bison grazing, both modern and historical. The data sets used in this analysis were derived from existing research and conservation properties located outside of Manhattan, KS (USA), which are home to stocker cattle, cow–calf production (CCS), and grazing bison. For stocker cattle, 10 years of animal production data (2007–2016) from season-long stocking (SLS, grazing 156 d) and intensive early stocking systems (IES; 76 grazing d and 2× stocking density) were used for GHG calculations. Enteric CH4, manure CH4, and direct nitrous oxide emissions were estimated using the IPCC tier 2 methodology. Historic bison (HGB) enteric CH4 estimates were calculated using a stocking density of 0.15 ha/animal and assuming that only 13% of grassland was used by bison each year. Within contemporary systems, IES had the lowest emissions (463.3 kg CO2-eq./ha/yr), while SLS, CCS, and MGB had the highest estimates (494.7, 493.9, and 595.9 kg CO2-eq./ha/yr, respectively). HGB had the lowest estimated annual emissions at 295.7 kg CO2-eq./ha/yr. These results imply that the historic grazing baseline of this grassland system is lower but similar to that of contemporary grazing cattle in the Great Plains region.

1. Introduction

The beef industry is under increasing pressure to reduce its contributions to climate change. Much of this stems from accounting efforts by greenhouse gas (GHG) reporting bodies such as the Intergovernmental Panel on Climate Change (IPCC) and the U.S. Environmental Protection Agency. According to the latest IPCC assessment report, enteric methane emissions represented 5.1% of total global GHG emissions, 23% of emissions from agriculture, forestry, and other land uses, and 27.2% of total global methane emissions [1]. In the U.S. specifically, enteric methane (CH4) emissions represent 3.1% of total U.S. GHG emissions, 32.6% of agriculture emissions, and 26.4% of total U.S. methane emissions [2]. When examining the role of beef production sectors in the U.S. (cow–calf production, stocker/backgrounder, and feedlot), the cow–calf sector is the largest contributor to GHG production [3]. This is driven primarily by enteric CH4 production, as these animals traditionally consume lower-quality, higher-fiber diets, which are key drivers of enteric CH4 emissions [4,5]. If we also consider that the stocker/backgrounder sector, a key economic driver in the Southern Great Plains, is typically forage-based, more than 80% of emissions come from pasture-based beef production [3].
Considering these emissions, many discussions centered on climate and food production often focus on how best to utilize land currently under the footprint of agriculture [6]. Hayek et al. [6] estimated that shifting food production away from animal-source foods to plant-based diets could sequester 332–547 GtCO2 in agricultural soils, improving our potential to achieve the 1.5 °C target outlined by the Paris Climate Accord [7]. Additionally, this shift could allow for “rewilding” of existing agricultural lands no longer needed for livestock production, with natural vegetation, herbivores, and other wildlife allowed to repopulate those landscapes [8]. Nested within this construct is the attribution of GHG fluxes to anthropogenic or natural sources, alternatively phrased as the Technosphere or Ecosphere [9]. Under traditional accounting, pasture-derived livestock GHG emissions are classified as anthropogenic, and wildlife emissions as natural. This classification is logical as livestock’s presence on these landscapes is dictated and manipulated by human involvement; however, our interpretation of the relevance of pasture-based emissions to anthropogenic climate change is not often discussed. As currently practiced, all emissions, such as the estimated 4891 kt of carbon dioxide equivalent (CO2eq.) emissions from beef cattle via enteric CH4 in the U.S. [2], are considered as anthropogenic, even though most of their production occurs in pasture-based systems.
In recent years, there has been interest, both within the U.S. and abroad, in examining how contemporary pasture production methods compare to “natural” or historic emissions on these landscapes from other herbivores [10,11,12]. On the Great Plains, bison (Bison bison) dominated the landscape in high populations, although the exact number varies depending on the source. Hristov [11] employed a range for bison population of 30 million to 75 million, which was used to estimate historic bison enteric CH4 production. These herds of bison were reported to have a high animal density per hectare, as bison migrated across the Plains in response to seasonality changes, forage availability, and other abiotic and biotic factors [13]. This type of behavior is closely related to a current beef production practice in the Southern Plains and Flint Hills of Kansas: seasonal stocker cattle grazing on native range. A common system employed in the region is intensive early stocking (IES), where cattle are stocked during the early forage growing season (May through July) at double the stocking rates of those used in season-long stocking (SLS) to allow adequate forage regrowth prior to burning the following March or April [14,15]. This grazing strategy takes advantage of the higher-quality forage present at the start of the forage growing season, thereby maximizing gains per hectare while animals are grazing and allowing ample time for the forage to recover [16]. To our knowledge, the emissions generated from this intensive seasonal grazing approach have not been compared to other modern grazing systems, to a modern “natural” system, or to historic emissions from migrating bison. While this systems approach is affected, in part, by differences in stocking rate, stocking density, and time spent grazing, it reflects the reality of what is occurring on the landscape. Further, these differences will be magnified on a daily level but, over a year, are reflective of the differences in the systems and/or management rather than solely being driven by animal type and subsequent dry matter intake. Therefore, the objective of this analysis was to examine how contemporary cattle production and bison grazing, both modern and historical, compare in terms of direct GHG emissions in the Flint Hills of Kansas.

2. Materials and Methods

All data were obtained from publicly available sources. IACUC approval was not required for this research. All GHG results are reported in kg CO2eq. values.

2.1. Stocker Cattle Emissions

In the Flint Hills region of Kansas, a common beef cattle production system is the seasonal grazing of growing male and female beef cattle. Data used to generate emission estimates for this experiment were derived from a long-term research project (2007–2016) of grazing steers southwest of Manhattan, Kansas (39°08′41.9″ N 96°31′45.7″ W). The site description is reported in detail by Owensby and Auen [14] and is similar across all scenarios modeled here. In brief, the forage base was a mixture of C4 and C3 plant species, with perennial grasses contributing 85% of the total plant composition. To mimic common production systems, two replicated grazing treatments were used here: (1) intensive early stocking (IES) and (2) season-long stocking (SLS). The IES treatment had double the stocking density (0.81 ha/steer) of the SLS treatment (1.62 ha/steer), and animals grazed for approximately half the duration. This resulted in the seasonal stocking rate being equal per unit of land. Average body weight—294 kg and 317 kg for IES and SLS, respectively—during the grazing period was calculated from the initial and final body weights reported by Owensby and Auen [14]. Forage intake was calculated using the NASEM [17] equations (Equation (1)) based on forage net energy for maintenance (NEm) and net energy for gain (NEg), using forage quality values reported by Weibert et al. [18] for native prairie.
Dry Matter Intake (% BW) = 1.2425 + 1.9218 × NEm − 0.7259 × NEm2
Total gross energy (GE) intake (estimated GE of 3.92 Mcal/kg of forage) was then utilized to calculate enteric CH4 production per hd/d using IPCC tier 2 equations, assuming 6.5% energy intake was lost as enteric CH4. The total kg CO2eq. produced was then calculated per ha/d and per ha/production season.

2.2. Cow–Calf Emissions

To calculate emissions for cow–calf production (CCS) on the same land base, the stocking rate applied in this analysis was 0.7 ha/animal unit month, as reported on a conservation site [19]. This is in alignment with a regional stocking rate of approximately 3.25 ha/cow–calf pair for a 6-month grazing season. To allow for season-long grazing, this stocking rate was doubled to 6.5 ha/cow–calf pair. Cows were estimated to weigh 617.68 kg and consume, on average, 2.2% of their BW each day [17]. Gross energy intake and enteric CH4 production were estimated using the same methods as the stocker cattle scenario. On average, cows were calculated to emit approximately 260 g CH4 /hd/d, which was then used to calculate emissions per unit ha/d and ha/yr.

2.3. Contemporary and Historic Bison Emissions

Modern grazing bison production (MGB) was modeled according to a published study from a conservation facility south of Manhattan, Kansas. Detailed information can be obtained from the Konza website (Bison|Konza Environmental Education Program) and the work published by Anguiano et al. [20]. The grazed land size was estimated at approximately 961 ha with a seasonal stocking rate of approximately 4.76 ha/animal. This results in an annual carrying capacity of 201 animal unit equivalents used for emission calculations. The site was moderately to lightly stocked, and animals were only handled once per year when culling, with the remainder of the year spent grazing continuously on the same land base. No rotations, anthelminthics, or other management was provided. Bison body weight was estimated at 454 kg which was obtained from the estimates of Craine et al. [21]. Dry matter intake estimates per animal unit were estimated at 2.5% of BW, which was the balance between the site-specific estimates of 2.9% and the 2.0% estimate used by Hristov [11]. Enteric CH4 estimations were then calculated according to Hristov [11], who calculated an emission factor of 21 g CH4/kg of DMI from the data of Galbraith et al. [22] and Kelliher and Clark [12]. As with the prior scenarios, emission estimates were then calculated on a kg of CO2eq./ha/d and /ha/yr basis.
To estimate the emissions of historic migratory grazing bison (HGB) on the same land base, adjustments were made to the stocking density and land use probability. First, a historic grazing density of 0.15 ha/animal was used to adjust intake per unit of land and emissions per year [12]. Next, a land use probability of 13% [12] was applied to adjust emissions relative to the likelihood of being utilized by historic migrating bison herds. Additionally, a biomass utilization rate (% of aboveground forage mass consumed by the animal) of 70% was used to determine the amount of time bison would need to stay on a given parcel of land at the given stocking rate. Also, a sensitivity analysis was conducted on the biomass utilization rate of bison by adjusting the rate to 50%, 70%, and 90%.

2.4. Manure Emissions

Manure emissions of CH4 and nitrous oxide (N2O) were calculated using the IPCC tier 2 methodology [23]. The assumptions described above for enteric CH4 calculations on animal size, populations, stocking rate, animal intake, and forage quality and quantity are nested within the calculations of manure emissions.
Manure methane emissions were calculated as a function of volatile solids composition based on dietary gross energy and digestible energy. As these systems are all grazing only, manure application was assumed to be 100% applied to pasture, with a methane conversion factor of 0.5% utilized for all systems [23]. For cattle, the ash content of manure was estimated to be 18.5%, which was the balance of ash content from Kissinger et al. [24,25]. For bison, ash content was estimated from Beyer et al. [26] at 15%. For N2O emissions, dietary NEg, body weights, and crude protein content of the forage were used to calculate total N intake and ultimately excreted N using the IPCC tier 2 approach. The key difference between the systems was the assumed crude protein value. For stocker systems, crude protein was assumed to be 12.1% to reflect that these animals only graze during times of above-average forage quality and are removed prior to fall, when plants move into dormancy and forage quality declines. A global N2O emission factor for bison of 0.018 N2O-N per kg of N excreted was obtained from Flessa et al. [27]. For the cow–calf and bison systems, a crude protein content of 9.3% was used to reflect their year-long utilization of the landscape. No fertilizer utilization was assumed in any system.

3. Results

Stocker cattle production systems resulted in the highest daily enteric CH4 emission rates per ha (Table 1). The IES system, with steers stocked at 0.81 ha/steer for 76 d, had an enteric CH4 emission rate of 4.8 kg CO2eq./ha/d and 365.3 kg CO2eq./ha/yr. The SLS system, with steers stocked at 1.6 ha/steer for 153 d, had an enteric CH4 emission rate of 2.6 kg CO2eq./ha/d and 396.0 kg CO2eq./ha/yr. The CCS resulted in the lowest daily enteric CH4 emission rate per ha. The cows, stocked at 6.5 ha/cow–calf pair for 12 months, had an emission rate of 1.1 kg CO2eq./ha/d. Additionally, CCS was between IES and SLS on a yearly basis at 408.9 CO2eq./ha/yr from enteric CH4.
For MGB production, the daily enteric CH4 emission rate was estimated to be 1.4 kg CO2eq./ha/d (Table 1). On a yearly basis, MGB production had the highest emission production estimate at 509.5 kg CO2eq./ha/yr. When examined from a historical perspective, the annual enteric CH4 emission estimates were more like CCS in the Flint Hills. On a yearly basis, HGB enteric CH4 emissions were estimated to be 252.8 kg CO2eq./ha. However, the daily emission rates were the highest of all modeled scenarios at 44.5 kg CO2eq./ha, which was driven by the high, albeit short, stocking density.
Total manure emissions were similar between production systems (Table 1). Daily relative emission rates were small; therefore, the results are presented as total manure emissions per year. The CCS, MGB, and HGB systems had the lowest total manure GHG emissions at 85.0, 86.4, and 42.9 kg CO2eq. ha/yr, respectively. The SLS and ILS systems had similar estimates for total manure GHG emissions at 98.6 and 98.0 kg CO2eq./ha/yr.
Between the systems, there was a stark difference in total annual GHG production per ha/yr between MGB and all other systems (Table 1). The MGB system had the highest estimated GHG emissions with an annual estimate of 595.9 kg CO2eq./ha/yr. This was 101 kg of CO2eq. higher than the next closest production system, which was the SLS system at 494.7 kg CO2eq./ha/yr. This difference would be equivalent to 148 additional beef steers being managed in an SLS production system. The total GHG emissions from the SLS system were similar to the CCS system, with emissions of 493.9 kg CO2eq./ha/yr. The HGB and IES systems were the lowest of all the production types. HGB had an estimated total of 295.7 kg CO2eq./ha/yr and the IES system was estimated at 463.3 kg CO2eq./ha/yr.
Given the large contribution of enteric CH4 emissions for each production system, we conducted a sensitivity analysis on the assumed forage utilization rate of HGB (Figure 1). Forage utilization rate was chosen as this impacts the amount of forage consumed and the amount of time the bison would be estimated to graze the land. The annual rate of enteric CH4 emissions was analyzed after shifting the biomass utilization rate to 50% or 90% compared to the 70% estimate and compared to our contemporary production systems. At a 50% forage utilization rate, enteric emissions were reduced to 180.6 kg CO2eq./ha/yr, considerably lower than any other production system. When the forage utilization rate was increased to 90%, emissions increased to 325.1 kg CO2eq./ha/yr, similar to the IES estimate of 365.3.

4. Discussion

One objective of this study was to explore how landscape-level direct GHG emissions are impacted by changing herbivore populations. Enteric CH4 emissions represented the largest source of GHG emissions from all systems. Enteric CH4 accounted for 80.5% and 85.5% of total GHG emissions for the cattle and bison systems, respectively. This large proportion of GHG emissions coming from enteric CH4 production makes intuitive sense and matches previous findings where GHG emissions from grazing systems were modeled. For example, Stanley et al. [28], in a partial life cycle assessment of beef production systems in Michigan, reported that enteric CH4 accounted for 67.6% of GHG emissions from grass-finished steers, when considering enteric and manure emissions only.
To our knowledge, the emission rates of CCS, SLS, and IES systems typical of the Kansas Flint Hills region have not been compared previously. Interestingly, of the assessed beef systems, the CCS system was most like the SLS system, with <1 kg difference in CO2eq./ha emitted per year. This similarity was because the CCS system emitted 12.9 kg CO2eq./ha from enteric CH4, while the SLS system emitted 14.1 kg CO2eq./ha of manure N2O on a yearly basis. When employing IES grazing management, there was a 6.3% reduction in yearly GHG emissions per ha. The IES system typically results in similar body weight gains per ha but in half the grazing time relative to the SLS system and with greater net returns to the producer [14]. Furthermore, IES has been demonstrated to be better for tallgrass prairie ecosystems, as it allows long periods of rest for the plants, thereby increasing native plants’ longevity and resilience [29]. Ultimately, IES reduces system GHG emissions, enhances ecosystem services, and increases producer profitability, thereby providing a sustainable management option.
In this study, we aimed to explore the direct GHG production of both contemporary cattle production, stocker cattle, and cow–calf systems, compared to modern grazing bison in a similar ecoregion. Given the historic importance of bison grazing in the Flint Hills ecosystem, we also sought to calculate the historic GHG emissions from those animals if they were grazing the same land resource. In recent years, several studies have aimed to compare the footprint of historic bison grazing in the Great Plains of the United States with modern beef cattle production [11,12] or the GHG production of wild ruminants compared to pastoral systems in other regions of the world [10]. In the United States, there has not been much work directly comparing the grazing systems that directly replaced the grazing bison in the Great Plains [13]. We found that total emissions from all cattle systems (IES, SLS, and CCS) were higher than those of HGB (considering a utilization rate of 70%; Table 1 and Figure 1). The grazing system that would most closely resemble that of the historic bison herd, the IES grazing method of double-stocking pastures but grazing for approximately 70 d, was ~37% different from HGB. This was primarily driven by enteric emissions (365.3 vs. 252.8 kg CO2-eq./ha/yr for IES and HGB, respectively) rather than manure emissions. This is similar to the findings of Hristov [11], who reported that CO2-eq. emissions from enteric CH4 were similar between farmed beef cattle, estimated at the time of that publication to be 4.74 Tg/yr of enteric CH4, and pre-settlement bison populations, if the bison population estimate at that time was between 30 and 50 million heads, at 61.6 and 102.7 Tg/yr, respectively. The duration that bison would have grazed any landscape was short enough that their higher daily rates of emissions were not enough to result in higher emissions per year on that landscape compared to any modern production system.
Compared to the other systems estimated here, the MGB had the highest emission rate, regardless of the source of emissions, and they were considerably higher than those from HGB. It should be noted that the bison herd used to generate this comparison is a moderately to lightly stocked system with minimal animal handling or interference, to monitor how the natural movements and behavior of grazing animals influence the Flint Hills ecoregion. One explanation for the results here is that the movement of bison, as a migratory animal where herds would have traditionally moved in response to season and forage quality changes [30], is no longer possible in today’s world. This alone would be a key driver of GHG emissions, particularly enteric CH4 emissions, as forage quality and availability vary greatly within a given year, and these are key drivers of enteric CH4 emissions [4,5]. The historic bison herd used in this analysis was migratory, with only a 13% chance of using the landscape each year and therefore were capable of searching for areas with higher forage quality (e.g., more digestible pasture), while MGB are limited to the available forage within their fenced area. However, our estimation for HGB is driven by the assumption of a forage utilization rate of 70%. This, in turn, influences time spent grazing the landscape and the amount of intake, and, ultimately, influences emission rates as well. When looking at the sensitivity analysis on forage utilization, what we found, unsurprisingly, was that as the forage utilization rates of HGB increased to 90%, so did the amount of enteric CH4 produced, approximately 325.1 kg CO2eq./ha/yr. This is like that of the IES, SLS, and CCS systems. This indicates that as bison migrated across the plains, emission rates could range from extremely low to matching those of modern emission rates but were dependent on forage quantity and utilization rate. Importantly, high biomass utilization is expected with high stocking densities. For example, Allison et al. [31] demonstrated that at high grazing pressure (10 kg of DM/animal unit/day), cattle consumed nearly 100% of the forage that was removed compared with 53% at light grazing pressures (50 kg DM/animal unit/day). This indicates that as stocking density increases, biomass utilization rate increases. Our results also agree with others [11,12], who showed that, given the unknowns of the historic bison herd, the emissions of the modern beef animals that replaced them on the landscape are similar to what would have otherwise been produced via natural herbivory.
The results of this analysis also bring into question the climate accounting of modern beef production in the United States, as it agrees with the literature on population-level GHG emissions [11,12,32] and further demonstrates that the emissions of the production methods that directly replaced grazing bison are similar to what would have otherwise been produced. Modern accounting frameworks dictate that all beef emissions are judged against those of unmanaged land which has low emission rates [33]. This type of accounting may overlook, or double count, the natural state of emissions and overestimate the emissions from anthropogenic sources, which is critical context in the discussion of climate policies and resource utilization [10]. Instead, the role of modern beef cattle emissions should be nuanced, considering what would have otherwise been produced or what will be produced if landscape decisions shift towards a “rewilding” framework. Considering “rewilding”, migratory animals could be considered only in vast, continuous areas [10], which is not possible in the modern U.S. and other developed countries [34]. Gordon et al. [34] reviewed four case studies of rewilding attempts throughout the world. The successful rewilding ventures utilized domestic grazing ruminants and some even sold meat harvested from the reserves. Ultimately, any attempt at “rewilding” will necessitate some degree of human intervention and management. Additionally, rewilding projects will need to incorporate herbivores, which would emit GHGs. In fact, many of the rewilding projects reviewed by Gordon et al. [34] take a similar approach to the Konza prairie reserve’s bison grazing enterprise considered in the current analysis. While it has not been directly assessed, the GHG emissions per ha per year from rewilding operations are potentially like what we modeled for the MGB system. Therefore, instead of removing beef production from landscapes, GHG emission reduction should be encouraged, and grazing management should aim to improve the natural ecosystem the beef industry relies on. Finally, these results agree with those of others [10] which indicate that the baseline emissions that grazing beef systems are compared against should not be emissions that would be released from a landscape devoid of ruminants but rather from an alternative system (e.g., a “rewilded” system) or the emissions that were historically produced by the native system. It should be noted, however, that this comparison only provides context on a GHG basis and is not a holistic perspective of how grazing ruminants interact and impact native range systems. There are numerous other ecosystem services outside of provisioning services that grazing herbivores influence, such as soil health, water quality, and wildlife habitat. These animals also have observable differences in landscape-level impacts which should be considered [35], particularly the similarity between GHGs seen in this study and others [10,11,12,32]. The bison herd used to generate the data for this experiment have been observed to increase plant biodiversity in the native Flint Hills prairie compared to beef cows grazing on adjacent property [35]. The discussion, therefore, on the use of grassland and rangeland landscapes should not be focused on that of GHG avoidance, equivalent to devoid landscapes, but rather the ecological or economic outcomes desired by the manager of the landscape.

5. Conclusions

Recent centuries have seen a dramatic shift in land use in the United States, away from vast prairie landscapes in the Great Plains to fragmented livestock and crop production. This shift in resource use has come at the expense of natural grassland systems and the traditional herbivores in the region, Bison bison. This has inevitably led to discussions on how best to utilize landscapes moving forward, although the discussion is currently centered on GHG tradeoffs rather than landscape-level impacts. The Flint Hills region of Kansas has two predominate livestock production systems—(1) stocker cattle (growing weaned calves) and (2) cow–calf production. We sought to compare the GHG emissions from these grazing cattle systems with bison grazing in the region, both modern and historical. We found that between the modern grazing systems, the emissions from IES were lower than other grazing systems on an annual basis and MGB had the highest. However, HGB had the lowest annual emissions of any modeled grazing system. Many of these results are driven by the stocking rate and variability inherent to each system but represent the reality of how the landscape is utilized. Additionally, given the similarity of the results, we implore the discussion around landscape-level impacts to shift away from GHG emissions and focus on desired ecological or economic outcomes desired by land managers.

Author Contributions

M.D.B. contributed to data analysis and manuscript drafting. L.R.T. contributed to data analysis and manuscript drafting. M.R.B., H.E.L. and C.M.S. contributed to manuscript drafting and interpretation of results. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

The following abbreviations are used in this manuscript:
GHGGreenhouse gas emission
IPCCInternational Panel on Climate Change
CH4Methane
CO2eqCarbon dioxide equivalent emissions
U.S.United States
IESIntensive early stocking
SLSSeason-long stocking
CCSCommercial cow–calf
MGBModern grazing bison
HBGHistoric grazing bison
HaHectare
N2ONitrous oxide
NEgNet energy for gain
NNitrogen
DDay

References

  1. Dhakal, S.; Minx, J.C.; Toth, F.L.; Abdel-Aziz, A.; Figueroa Meza, M.J.; Hubacek, K.; Jonckheer, I.G.C.; Kim, Y.; Nemet, G.G.; Pachauri, S.; et al. Emissions Trends and Drivers. In Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change; Shukla, P.R., Skea, J., Slade, R., Al Khourdajie, A., van Diemen, R., McCollum, D., Pathak, M., Some, S., Vyas, P., Fradera, R., et al., Eds.; Cambridge University Press: Cambridge, UK, 2023; pp. 215–294. ISBN 9781009157926. [Google Scholar]
  2. EPA. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2022; U.S. Environmental Protection Agency: Washington, DC, USA, 2024.
  3. Rotz, C.A.; Asem-Hiablie, S.; Place, S.; Thoma, G. Environmental Footprints of Beef Cattle Production in the United States. Agric. Syst. 2019, 169, 1–13. [Google Scholar] [CrossRef]
  4. Johnson, K.A.; Johnson, D.E. Methane Emissions from Cattle. J. Anim. Sci. 1995, 73, 2483–2492. [Google Scholar] [CrossRef]
  5. Thompson, L.R.; Rowntree, J.E. Invited Review: Methane Sources, Quantification, and Mitigation in Grazing Beef Systems. Appl. Anim. Sci. 2020, 36, 556–573. [Google Scholar] [CrossRef]
  6. Hayek, M.N.; Harwatt, H.; Ripple, W.J.; Mueller, N.D. The Carbon Opportunity Cost of Animal-Sourced Food Production on Land. Nat. Sustain. 2021, 4, 21–24. [Google Scholar] [CrossRef]
  7. UNFCCC. The Paris Agreement; UNFCCC: Paris, France, 2016. [Google Scholar]
  8. Cromsigt, J.P.G.M.; Beest, M.T.; Kerley, G.I.H.; Landman, M.; Roux, E.L.; Smith, F.A. Trophic Rewilding as a Climate Change Mitigation Strategy? Philos. Trans. R. Soc. B Biol. Sci. 2018, 373, 20170440. [Google Scholar] [CrossRef]
  9. Crenna, E.; Sozzo, S.; Sala, S. Natural Biotic Resources in LCA: Towards an Impact Assessment Model for Sustainable Supply Chain Management. J. Clean. Prod. 2018, 172, 3669–3684. [Google Scholar] [CrossRef]
  10. Manzano, P.; del Prado, A.; Pardo, G. Comparable GHG Emissions from Animals in Wildlife and Livestock-Dominated Savannas. npj Clim. Atmos. Sci. 2023, 6, 27. [Google Scholar] [CrossRef]
  11. Hristov, A.N. Historic, Pre-European Settlement, and Present-Day Contribution of Wild Ruminants to Enteric Methane Emissions in the United States. J. Anim. Sci. 2012, 90, 1371–1375. [Google Scholar] [CrossRef]
  12. Kelliher, F.M.; Clark, H. Methane Emissions from Bison-An Historic Herd Estimate for the North American Great Plains. Agric. For. Meteorol. 2010, 150, 473–477. [Google Scholar] [CrossRef]
  13. Flores, D. Bison Ecology and Bison Diplomacy: The Southern Plains from 1800 to 1850. In Agriculture, Resource Exploitation, and Environmental Change; Routledge: Oxfordshire, UK, 1991; Volume 78. [Google Scholar]
  14. Owensby, C.E.; Auen, L.M. Steer and Pasture Productivity Influenced by Intensive Early Stocking plus Late Season Grazing. Crop Forage Turfgrass Manag. 2018, 4, 1–7. [Google Scholar] [CrossRef]
  15. Smith, E.F.; Owensby, C.E. Intensive-Early Stocking and Season-Long Stocking of Kansas Flint Hills Range. J. Range Manag. 1978, 31, 14. [Google Scholar] [CrossRef]
  16. Owensby, C.E.; Auen, L.M.; Berns, H.F.; Dhuyvetter, K.C. Grazing Systems for Yearling Cattle on Tallgrass Prairie. Rangel. Ecol. Manag. 2008, 61, 204–210. [Google Scholar] [CrossRef]
  17. NASEM. Nutrient Requirements of Beef Cattle, 8th ed.; Galyean, M.L., Beauchemin, K.A., Caton, J.S., Cole, N.A., Eisemann, J.H., Engle, T., Erickson, G.E., Krehbiel, C.R., Lemenager, R.P., Tedeschi, L.O., Eds.; National Academies of Sciences: Washington, DC, USA, 2016. [Google Scholar]
  18. Weibert, C.S.; Spore, T.J.; Johnson, M.A.; Brazle, F.K.; Kuhl, G.L.; Hollenbeck, W.R.; Wahl, R.N.; Blasi, D. Evaluation of Salt, Trace Mineral Sources, and Growth Implants on Performance of Stocker Cattle Grazing Native Flint Hills Pasture. Kans. Agric. Exp. Stn. Res. Rep. 2018, 4, 1–6. [Google Scholar] [CrossRef]
  19. Olson, K. PBG06 Cattle Grazing and Cattle Performance in the Patch-Burn Grazing Experiment at Konza Prairie. Available online: https://portal.edirepository.org/nis/mapbrowse?packageid=knb-lter-knz.120.3 (accessed on 28 May 2025). [CrossRef]
  20. Anguiano, N.V.; Freeman, K.M.; Figge, J.D.; Hawkins, J.H.; Zeglin, L.H. Bison and Cattle Grazing Increase Soil Nitrogen Cycling in a Tallgrass Prairie Ecosystem. Biogeochemistry 2024, 167, 759–773. [Google Scholar] [CrossRef]
  21. Craine, J.M.; Towne, E.G.; Elmore, A. Intra-Annual Bison Body Mass Trajectories in a Tallgrass Prairie. Mammal Res. 2015, 60, 263–270. [Google Scholar] [CrossRef]
  22. Galbraith, J.K.; Mathison, G.W.; Hudson, R.J.; Mcallister, T.A.; Cheng, K.-J. Intake, Digestibility, Methane and Heat Production in Bison, Wapiti and White-Tailed Deer. Can. J. Anim. Sci. 1998, 78, 681–691. [Google Scholar] [CrossRef]
  23. IPCC. 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories; Buendia, C., Tanabe, K., Kranjc, A., Baasansuren, J., Fukuda, M., Ngarize, S., Osako, A., Pyrozhenko, Y., Shermanau, P., Federici, S., Eds.; IPCC: Geneva, Switzerland, 2019; ISBN 978-4-88788-232-4. [Google Scholar]
  24. Kissinger, W.F.; Member, A.; Koelsch, R.K.; Erickson, G.E.; Klopfenstein, T.J.; Kissinger, W.F.; Koelsch, R.K.; Erickson, G.E. Characteristics of Manure Harvested from Beef Cattle Feedlots. Appl. Eng. Agric. 2007, 23, 357–365. [Google Scholar] [CrossRef]
  25. Kirchmann, H.; Witter, E. Composition of Fresh, Aerobic and Anaerobic Farm Animal Dungs. Bioresour. Technol. 1992, 40, 137–142. [Google Scholar] [CrossRef]
  26. Beyer, W.N.; Connor, E.E.; Gerould, S. Estimates of Soil Ingestion by Wildlife. J. Wildl. Manag. 1994, 58, 375–382. [Google Scholar] [CrossRef]
  27. Flessa, H.; Dörsch, P.; Beese, F.; König, H.; Bouwman, A.F. Influence of Cattle Wastes on Nitrous Oxide and Methane Fluxes in Pasture Land. J. Environ. Qual. 1996, 25, 1366–1370. [Google Scholar] [CrossRef]
  28. Stanley, P.L.; Rowntree, J.E.; Beede, D.K.; DeLonge, M.S.; Hamm, M.W. Impacts of Soil Carbon Sequestration on Life Cycle Greenhouse Gas Emissions in Midwestern USA Beef Finishing Systems. Agric. Syst. 2018, 162, 249–258. [Google Scholar] [CrossRef]
  29. Hickman, K.R.; Hartnett, D.C.; Cochran, R.C.; Owensby, C.E. Grazing management effects on plant species diversity in tallgrass prairie. J. Range Manag. 2004, 57, 58–65. [Google Scholar] [CrossRef]
  30. Reynolds, H.W.; Gates, C.C.; Glaholt, R.D. Bison (Bison Bison). In Wild Mammals of North America; Feldhamer, G.A., Thompson, B.C., Chapman, J.A., Eds.; The Johns Hopkins University Press: Baltimore, MD, USA, 2003; pp. 1009–1060. [Google Scholar]
  31. Allison, C.D.; Kothmann, M.M.; Rittenhouse, L.R. Efficiency of Forage Harvest by Grazing Cattle. J. Range Manag. 1982, 35, 351–354. [Google Scholar] [CrossRef]
  32. Smith, F.A.; Hammond, J.I.; Balk, M.A.; Elliott, S.M.; Lyons, S.K.; Pardi, M.I.; Tomé, C.P.; Wagner, P.J.; Westover, M.L. Exploring the Influence of Ancient and Historic Megaherbivore Extirpations on the Global Methane Budget. Proc. Natl. Acad. Sci. USA 2016, 113, 874–879. [Google Scholar] [CrossRef]
  33. IPCC. IPCC Guidelines for National Greenhouse Gase Inventories; IPCC: Geneva, Switzerland, 2006; Volume 2. [Google Scholar]
  34. Gordon, I.J.; Manning, A.D.; Navarro, L.M.; Rouet-Leduc, J. Domestic Livestock and Rewilding: Are They Mutually Exclusive? Front. Sustain. Food Syst. 2021, 5, 550410. [Google Scholar] [CrossRef]
  35. Ratajczak, Z.; Collins, S.L.; Blair, J.M.; and Nippert, J.B. Reintroducing bison results in long-running and resilient increases in grassland diversity. Proc. Natl. Acad. Sci. USA 2022, 119, e2210433119d. [Google Scholar] [CrossRef]
Ruminants 05 00034 g001
Figure 1. Sensitivity analysis of historic bison forage utilization (consumption and time spent grazing) and impacts on annual methane emissions (kg CO2-eq.).
Figure 1. Sensitivity analysis of historic bison forage utilization (consumption and time spent grazing) and impacts on annual methane emissions (kg CO2-eq.).
Ruminants 05 00034 g001
Table 1. Greenhouse gas emissions (kg CO2eq.) per ha per d or per ha per year by production system.
Table 1. Greenhouse gas emissions (kg CO2eq.) per ha per d or per ha per year by production system.
Enteric CH4Manure CH4Manure N2OTotal Manure GHGTotal GHG
Production Type */ha/d/ha/yr/ha/d/ha/yr/ha/d/ha/yr/ha/yr/ha/yr
CCS1.1408.90.014.50.280.185.0493.9
MGB1.4509.50.013.70.283.386.4595.9
IES4.8365.30.064.41.293.698.0463.3
SLS2.6396.00.034.40.694.298.6494.7
HGB44.5252.80.261.51.341.442.9295.7
* CCS = contemporary cow–calf; MGB = modern grazing bison; IES = intensive early stocking; SLS = season-long stocking; HGB = historic bison grazing.
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De Bernardi, M.; Salisbury, C.M.; Larson, H.E.; Beck, M.R.; Thompson, L.R. Comparison of Contemporary Grazing Cattle and Bison Greenhouse Gas Emissions in the Southern Great Plains. Ruminants 2025, 5, 34. https://doi.org/10.3390/ruminants5030034

AMA Style

De Bernardi M, Salisbury CM, Larson HE, Beck MR, Thompson LR. Comparison of Contemporary Grazing Cattle and Bison Greenhouse Gas Emissions in the Southern Great Plains. Ruminants. 2025; 5(3):34. https://doi.org/10.3390/ruminants5030034

Chicago/Turabian Style

De Bernardi, Maria, Carlee M. Salisbury, Haley E. Larson, Matthew R. Beck, and Logan R. Thompson. 2025. "Comparison of Contemporary Grazing Cattle and Bison Greenhouse Gas Emissions in the Southern Great Plains" Ruminants 5, no. 3: 34. https://doi.org/10.3390/ruminants5030034

APA Style

De Bernardi, M., Salisbury, C. M., Larson, H. E., Beck, M. R., & Thompson, L. R. (2025). Comparison of Contemporary Grazing Cattle and Bison Greenhouse Gas Emissions in the Southern Great Plains. Ruminants, 5(3), 34. https://doi.org/10.3390/ruminants5030034

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