Flexible stocking: Livestock production and economic responses in mixed-grass prairie

Authors: Derner, Justin; RITTEN, JOHN - Colorado State University; BALDWIN, TEVYN - Platte Valley Bank; JORNS, TAMARAH - Natural Resources Conservation Service (NRCS, USDA); Mortenson, Matthew; Augustine, David

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Rangeland managers would like to match animal demand to available forage for optimal grazing management of livestock, but this is difficult in environments with high variability in rainfall across years. Rather than use flexible stocking rates, managers typically use moderate stocking rates and then remove livestock when forage is low due to drought conditions or stockpile extra forage when rainfall is favorable for dormant season grazing or for use in the early part of the next grazing season. We compared flexibility in stocking rates across years, using predicted forage amounts from prior research results, to a fixed moderate stocking rates for seven years (2016-2022) in northern mixed-grass prairie in Wyoming. Across years, stocking rate for the flexible stocking treatment range considerably, but cumulative total beef production for the seven years was similar for the flexible (263.0 pounds/acre) and moderate (257.6 pounds/acre) stocking rates. Diet quality of the livestock (yearling heifers), crude protein and digestible organic matter, and diet composition was similar for the flexible and fixed moderate stocking rates. Compared to moderate stocking, flexible stocking did result 7% lower cumulative gross and 11% lower net economic returns per yearling. Advancements in predictive forage forecasting tools and remote sensing capabilities, along with upgraded seasonal weather forecasts, are needed for improving flexible stocking strategies for managers.

Technical Abstract: Matching animal demand to forage availability is a core principle in sustainable rangeland management. We evaluated the use of interannual flexibility in stocking rates compared to fixed stocking at light, moderate, and heavy stocking rates on livestock weight gains and economic responses for seven years (2016-2022) in North American northern mixed-grass prairie. The grazing season began in early June each year, so stocking rates in the flexible treatment were calculated based on the amount of forage production predicted from actual precipitation received in April and May combined with long-term mean annual precipitation received at the study site in June, as well as an adjustment in stocking rate based on the amount of residual forage remaining at the end of the previous grazing season. Across years, mean stocking rate for the flexible stocking treatment (32.5 AUD ha-1) was between the heavy (38.6 AUD ha-1) and moderate (29.7 AUD ha-1), and was twice as high as the light (15.8 AUD ha-1). Cumulative total beef production for the seven years was highest with heavy stocking (282.6 kg ha-1), 17% less in the flexible (234.2 kg ha-1) and 19% less in the moderate (229.4 kg ha-1) stocking rates, and 55% lower with light stocking (128.4 kg ha-1). Crude protein and digestible organic matter, as well as composition of plant functional groups in diets of yearlings did not differ between the moderate versus the flexible stocking treatments. Compared to moderate stocking, flexible stocking resulted in 6.9% lower cumulative gross ($2,299.05) and 10.8% lower net ($1,407.37) economic returns per yearling. We suggest that future evaluations of flexible stocking strategies consider incorporating seasonal weather forecasts combined with intra-seasonal adjustments in stocking rates as the growing season unfolds. Advancements in predictive forage forecasting tools and remote sensing capabilities are needed to support such a strategy.