ÉTUDE SUR LES PORCS DE RACE CONTRÔLÉS À LA FERME AU QUÉBEC. 1. SOURCES DE VARIATION

Abstract

Sources of variation for growth, for backfat and for a phenotypic index were studied in Quebec purebred Yorkshire, Landrace, Hampshire and Duroc pigs. A total of 94,161 records of backfat measures and of age and weight at the end of test, accumulated between 1977 and 1985, was used in this work. Weight at the end of test was found to be an important source of variation, so growth data were adjusted to 90 kg by linear regression (R2 between 31 and 52%). Gender, parity number, year-season, birth years of parents and herd were also significant factors. Therefore, they will be included as fixed effects in the mixed model to be used to evaluate heritabilities and genetic correlations. Key words: Pig, variation, environmental factors, home test