Genetic parameters of mule ducks meat and fatty liver performances simultaneously estimated in both parental liness : [Preprint]

Genetic parameters of traits related to hepatic lipid metabolism, carcass composition and products quality of overfed mule ducks were estimated on both parental lines of this hybrid: the "common duck" line (C), for the maternal side and the "Muscovy" line (M), for the paternal side. The originality of the statistical model was to include simultaneously the additive genetic effect of the common ducks and that of the Muscovy ducks, revealing a higher genetic determinism in C than in M. Reported estimates have to be multiplied by 4 to get equivalent to intrapopulation estimates. Carcass composition traits were highly heritable in C with values ranging from 0.16 for liver weight, 0.24 for carcass weight and 0.25 for abdominal fat weight to 0.32 for breast muscle weight. Heritabilities of technological outputs were higher for the fatty liver (0.17 and 0.09 respectively on C and M sides for liver melting rate) than for the Pectoralis major muscle (0.03 either on C or M sides for cooking losses). The liver melting rate was strongly correlated with the liver lipid contents (about +0.90). The fact that most parameters are heritable in both lines allows more effective schemes of genetic improvement by selection. However, traits such as breast meat quality with low heritability will be hard to improve by selection.