A simulation model of sheep production systems for Chilean'|s austral zone

Giorgio Castellaro G.1, David Rodrfguez S.2 y Luis Sáez T.3

A sheep production simulation model was carried out, for the Southern Zone of Chile, which purpose was to evaluate sheep behaviour, under different management choices, in several ecological enviroments. The model was programmed on Quick Basic language, and it was divided in two levels of organization. The first one was related with the information that fed the model, processment and building of results files. On a second level, there were situated biological subjects, for which subrutines had been used and designed for such purposes. For the evaluation of the model behaviour, simulations of two physical modules of sheep production were done, which were developed in the area where the trial was carried out. The model predicted on a reasonable way, the animal weight variation, obtaining correlations on real and simulated values, thatfluctuated between 93.2 and 94.8% (P<0.001). Therewere obtained values on wool and meat production per hectarea, similarto reality, but reproductive rates were subestimated. It is very important to improve the model, specially in those points related to grassland growth, and the intake process done by sheep under grazing conditions.

Keywords: sheep, simulation models, productive systems, natural grassland.
1 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.
2 Actualmente en actividad privada, El Arcangel 4955, Depto. 81, Las Condes, Santiago, Chile.
3 AGROPROSEM, Serrano 297, Santiago, Chile.