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Model Development for a Deferred-grazing System
Author
Smith, R. C. G.
Williams, W. A.
Publisher
Society for Range Management
Publication Year
1973-11-01
Body

A model of the early growth of an annual pasture and liveweight response of grazing sheep was built using first order differential equations to study the practice of deferred grazing. The dynamic behavior of the system over time was simulated by solving the equations on a computer. The model is an interpretative representation of a subterranean clover pasture in Western Australia and relates to a specific site and set of seasonal conditions. Use was made of the literature and a recent grazing experiment to develop the model. Herbage growth is estimated from known relationships with radiation received, leaf area exposed, soil moisture, and herbage removed by grazing. Change in soil moisture is estimated from rainfall and pan evaporation data. Defoliation is based on stocking rate, pasture weight, and pasture height to account for the effects of animal numbers and availability of pasture. Liveweight change of the consuming animal is calculated as a function of intake, digestibility, and the partitioning of metabolizable energy between maintenance and weight change. Validation of the model by results observed in the grazing experiment is presented. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020

Language
en
Resource Type
Text
Document Type
Journal Issue/Article
Digital Object Identifier (DOI)
10.2307/3896986
Additional Information
Smith, R. C., & Williams, W. A. (1973). Model development for a deferred-grazing system. Journal of Range Management, 26(6), 454-460.
ISSN
0022-409X
OAI Identifier
oai:repository.arizona.edu:10150/647297
Journal Volume
26
Journal Number
6
Journal Pages
454-460
Collection
Rangeland Ecology & Management (REM)
Journal Name
Journal of Range Management
Keywords
Model Development
Early Growth
Liveweight Response
Differential Equations
Subterraneal Clover Pasture
Pasture Height
Meat Produced
growth rate
defoliation
herbage weight
deferred grazing
herbage growth
continuous grazing
Western Australia
density
soil moisture
plant density
sheep
stocking rate