ARS | Publication request: Relationships between forage allowance and grazing efficiency in the Great Plains: Implications for managing rangelands for both livestock production and desired ecosystem goods and services

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract
Publication Acceptance Date: September 6, 2008
Publication Date: N/A

Technical Abstract: Emergence of desired ecosystem goods and services from rangelands as a societal benefit and a potential income source for land managers has implications regarding the management of plant communities traditionally used primarily for livestock production. Contemporary decision-making on rangelands in the North American Great Plains requires a clearer understanding of the influence of forage allowance on grazing efficiency to provide a basis for comparative evaluations of alternative management approaches involving the interface of livestock production and desired ecosystem goods and services. Our main objective was to evaluate the relationship between forage allowance and grazing efficiency using data from eight studies conducted throughout the Great Plains. Additional relationships between forage allowance, utilization, and animal production were also evaluated. Negative exponential functions described relationships between 1) forage allowance and grazing efficiency (R2=0.93), 2) forage allowance and utilization (R2=0.91), and 3) forage allowance and animal production per unit land area (R2=0.80). In contrast, a positive logarithmic function described the relationship between forage allowance and animal daily gains (R2=0.91). Across the eight study locations, forage allowances of 20, 40 and 100 kg for an animal unit day (AUD) resulted in 70%, 50% and 20% grazing efficiency, respectively. The developed relationship between forage allowance and grazing efficiency provides a basis to evaluate how alternative management scenarios designed to accomplish conservation-oriented objectives, such as production of desired ecosystem goods and services, will affect livestock production. Additional efforts will be needed to determine the economic opportunity costs and returns associated with modifications in management.