Paramètres génétiques des principales anomalies congénitales porcines

Abstract

Congenital disorders are a preoccupation in pig breeding although their incidence is very limited, around 1%. They induce mortality, carcass depreciation, and remarks on animal welfare. The main disorders registered in French pig populations are scrotal and umbilical hernia, cryptorchidism and intersexuality. Disorder frequencies are known to be influenced by feeding and sanitary environmental factors but also by genetic factors. Genetic basis of these disorders is poorly known. The present study reports heritability values estimated from data recorded in three pig populations (A, B, C). Parameters were estimated in families with at least one affected animal using a discrete modelisation with a threshold model. For the population A, heritability values were found to be moderate for scrotal and umbilical hernia (0.27 and 0.37, respectively), low for cryptorchidism (0.11) and high for intersexuality (0.81). Due to small numbers of affected animals, heritability values were estimated only for umbilical hernia (0.60) and scrotal hernia (0.06) in the population B and could not be estimated in the population C. When genetic parameters were estimated considering the three populations altogether, heritability values were very similar to those estimated in the A population alone.