Genetic evaluation of carcass traits in dairy cattle

Abstract

Two new genetic evaluations on carcass data, extracted from the Normabev database, have been developed by the UMT 3G (Gestion Génétique et Génomique des populations bovines). The first (VC) is a multi-breed evaluation of sires on their ability to produce veal calves. It evaluates sires of dual-purpose breeds Montbeliarde (MON) or Normande (NOR) and sires of beef breeds mated with dairy cows. The second (YB) evaluates sires of the MON, NOR and Simmental (SIM) breeds on their ability to produce young bulls for slaughter. The YB evaluation considers three traits simultaneously (carcass weight, age at slaughter and carcass conformation), the VC four (the same three, plus meat color). Heritability estimates are moderate to quite high for carcass weight and conformation (0.12 to 0.37, depending on the breed and the evaluation), lower for age at slaughter and meat color (0.05 to 0.27). Genetic correlations between carcass weight and conformation and between carcass weight and age at slaughter are favorable. Genetic correlations between YB traits on the one hand and VC, milk production and female type traits on the other hand were also estimated. These correlations are low to moderate (favorable) between YB and milk production. Hence, meat production traits can be improved without compromising genetic trends on milk production traits too much. YB traits are favorably correlated with VC (0.32 to 0.70) and female type traits. VC polygenic evaluations became official in 2015. YB polygenic evaluations will be official in 2017. YB and VC genomic evaluations are currently developed in MON and NOR, following the methodology applied in other dairy cattle genomic evaluations.