Skip to main content
ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #429206
Research Project: Knowledge Systems and Tools to Increase the Resilience and Sustainability of Western Rangeland Agriculture

Location: Range Management Research

Title: Gas flux quantification of Angus x Hereford and Rarámuri Criollo cows grazing extensive arid rangelands

Author
item SPETTER, MAXIMILLIANO - New Mexico State University
item UTSUMI, SANTIAGO - New Mexico State University
item ANDRES, PEREA - New Mexico State University
item FUNK, MICAH - New Mexico State University
item Macon, Lara
item Bestelmeyer, Brandon
item Spiegal, Sheri
item Cibils, Andres
item Estell, Richard

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/11/2025
Publication Date: 9/13/2025
Citation: Spetter, M.J., Utsumi, S.A., Andres, P.R., Funk, M., Macon, L.K., Bestelmeyer, B.T., Spiegal, S.A., Cibils, A.F., Estell, R.E. 2025. Gas flux quantification of Angus x Hereford and Rarámuri Criollo cows grazing extensive arid rangelands. Society for Range Management Meeting Abstracts. Abstract.

Interpretive Summary:

Technical Abstract: Measuring carbon gas fluxes from cattle is critical for understanding ruminant production and environmental impact; however, no data is available on gas fluxes from cattle grazing arid rangelands in the Southwestern USA. Methane (CH4), carbon dioxide (CO2), and oxygen (O2) fluxes were measured from 22 Angus x Hereford (AH; metabolic body weight [MBW]: 107±14 kg) and 44 Rarámuri Criollo (RC; MBW: 82±8 kg) cows using a portable automated head-chamber system (GreenFeed, C-Lock Inc., USA). The study was conducted on arid rangeland pastures at the USDA-ARS Jornada Experimental Range, NM, USA. The sampling period extended from April 1, 2024 to March 31, 2025. A switchback design was used, with the GreenFeed unit alternated between herds every 15–21 days to minimize spatiotemporal confounding. Gas fluxes were expressed as grams/cow/day (g/d) and grams/kilogram of MBW/day (g/kgMBW). Data were analyzed using a linear mixed-effects model, including Breed (AH, RC), Season (Spring2024, Summer2024, Fall2024, Winter2025), and their interaction as fixed effects. A random intercept for Cow accounted for repeated measures. A significant Breed x Season interaction was observed for all three gases (p<0.0001). As expected, daily gas fluxes (g/d) were higher for AH (CH4: 115.6–173.6; CO2: 4735.2–7474.9; O2: 3845.9–5931.9) than RC (CH4: 95.9–103.3; CO2: 3940.2–4753.3; O2: 3270.5–3827.8) across all seasons (p<0.0001). However, when expressed per unit of MBW (g/kgMBW), gas fluxes were higher (p<0.0001) for AH than RC only during Summer2024 (CH4: 1.62 vs. 1.23; CO2: 70.2 vs. 58.05; O2: 55.6 vs. 46.6). These findings suggest divergent fermentative and metabolic activity between breeds specifically in Summer2024, when forage production and quality are typically greatest. The RC breed appears to be more efficient under these conditions, a difference potentially explained by genetic makeup, grazing behavior, among other factors. These underlying mechanisms will be explored in future studies.