Incorporating virtual fencing to manage yearling steers on extensive rangelands: Spatial behavior, growth performance, and enteric methane emissions

Authors: RAYNOR, EDWARD - Colorado State University; SHADBOLT, ANNA - Colorado State University; Johnston, Melissa; Augustine, David; Derner, Justin; KEARNEY, SEAN - Thunder Basin Grasslands Prairie Ecological Association; RITTEN, JOHN - Colorado State University; DELAY, NATHAN - Colorado State University; CARVALHO, PEDRO - Colorado State University; VARGAS, JUAN - Colorado State University; PLACE, SARA - Colorado State University; STACKHOUSE-LAWSON, KIMBERLY - Colorado State University

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2025
Publication Date: 9/10/2025
Citation: Raynor, E.J., Shadbolt, A.M., Johnston, M.K., Augustine, D.J., Derner, J.D., Kearney, S.P., Ritten, J.P., Delay, N.D., Carvalho, P.H., Vargas, J., Place, S.E., Stackhouse-Lawson, K.R. 2025. Incorporating virtual fencing to manage yearling steers on extensive rangelands: Spatial behavior, growth performance, and enteric methane emissions. Frontiers in Veterinary Science. 12. Article e1637190. https://doi.org/10.3389/fvets.2025.1637190.
DOI: https://doi.org/10.3389/fvets.2025.1637190

Interpretive Summary: Targeted grazing is possible with precision livestock management. In the semiarid, shortgrass prairie, we evaluated this technology of virtual fencing to target graze certain plant communities in a pasture versus paired pastures where yearling steers had unrestricted access to the entire pasture during the summer grazing season. We evaluated weight gains and gas flux – the latter measured with automated head chamber systems. In a cool-season grass dominated pasture, target grazing with virtual fence reduced both weight gain and enteric methane (CH4) emissions compared to unrestricted grazing. In a pasture with diverse plant communities, target grazing with virtual fence did not affect weight gains but did increase enteric methane emissions. We suggest that virtual fence has potential for use by ranchers, but they will need to have solid on-the-ground understanding of plant diet quality to effectively utilize virtual fence to achieve desirable outcomes for both weight gain and enteric methane emissions.

Technical Abstract: We examined growth rates, gas flux, and movement behavior of beef cattle within a targeted grazing experiment in shortgrass steppe, implemented using virtual fence (VF). Over the 110-d grazing season (mid-May to early September), one hundred twenty British-breed stocker steers (~12 months of age; body weight 382 kg ± 35) were grazed with VF management (active collars) or free-range (non-active collars) in two sets of 130 ha pasture pairs (i.e., VF-managed vs. control), dominated by cool-season native grasses or a diverse mosaic of native grasses. Automated head chamber systems (AHCS) assessed the gas flux of steers in each pasture while GPS collars recorded movement of individual animals and governed animal distribution if the VF system was activated. Within each pair of pastures, one herd of steers was VF-managed, where multiple VF-delineated sub-pastures were created to focus steer distribution on specific native plant communities in an attempt to optimize access to high quality forage throughout the grazing season for increasing production efficiency of these steers, whereas the control pastures, steer distribution was not managed with VF and animals had access to the entire pasture for the grazing season. In the cool-season grass-dominated pasture, VF management reduced enteric methane (CH4) emissions (p = 0.01), but the growth rate of steers was lower compared to control steers (p = 0.03). In the diverse mosaic pasture, VF management increased enteric CH4 emissions per unit of production (p = 0.03) but did not decrease growth rate compared to control steers (p = 0.09). These findings suggest that targeted grazing implemented via VF technology can have varying effects on methane emissions of yearling steers grazing during the summer grazing season in shortgrass prairie depending on the types of plant communities involved, and that the use of VF management on available diet quality for steers will influence production efficiency in extensive rangelands.