A SIMULATION-MODEL OF GRAZING SHEEP .1. ANIMAL GROWTH AND INTAKE

This paper is the first in a series that presents the development and use of a quantitative model of a sheep grazing system. The animal growth model presented here draws from a range of sources reported in the literature, and accounts for interactions between an animal's physiological state and herbage quality on diet selection and levels of feed intake. The model estimates partition of energy between maintenance, pregnancy, lactation, wool growth and fat and protein accretion. The model was tested against a range of published data and was found to be acceptable for its intended use as a research tool to evaluate animal performance and the physical and economic-consequences of alternative technologies and management strategies.