FR 47. Chinchilla (Chinchilla lanigera) body growth in a commercial production, province of Buenos Aires. Argentina
From the analysis of body growth, as one of the possible animal responses, problems werw detected related to the management systems, so we could produce inferences about the possible strategies in order to improve production. Many different models were use to fit a wide range of studies of body growth in many species. The aims of this paper was to mesasure the gowth of Chinchilla lanigera in a commercial breeding station in order to propose changes in the present system of fur production. We made three weighings of 103, 230 and 262 animals at different times. The age of them was well known. The linear, multiplicative, logistic, Von Bertalanffy and Gompertz functions were each fitted to the growth observed in this population of Ch. lanigera. The model that best describe the corporal growth of the individuals under study was Gompertz, for all animals, males and females. Even the females show bigger adult weight than males, which had a faster weight gain than females. This study suggests the following changes in the actual management system: 1) It is recomended to use two different diets: for growing and reproduction. 2) the optimal slaughter age and weight for females and males are 500 and 300 days old, with 640 and 530 g, respectively. 3) The male preselection should be 430 g at 150 d old but the selection criteria for reproduction stock of males should be 590 g at 300 d old, taking in account the fur quality. 4) The female reproduction age should start at 190 d old with more than 520 g.