Issue Date
1973-11-01Keywords
Model DevelopmentEarly 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
Metadata
Show full item recordCitation
Smith, R. C., & Williams, W. A. (1973). Model development for a deferred-grazing system. Journal of Range Management, 26(6), 454-460.Publisher
Society for Range ManagementJournal
Journal of Range ManagementDOI
10.2307/3896986Additional Links
https://rangelands.org/Abstract
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.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/3896986