A first attempt of an international genetic evaluation of beef breeds in Europe

Weaning weights from 1,608,739 Charolais calves performance recorded in France (FRA), Great Britain (GBR) and Ireland (IRL) were analysed to produce the first international genetic evaluation for the breed. An animal model with maternal genetic and permanent environment effects was used to stimate 2,065,626 breeding values for each genetic effect. A preliminary analysis showed significantly heterogeneous residual variances across countries. Estimates of the genetic correlations between weaning weights measured in different countries ranged from 0.55 (SE = 0.25) to 0.90 (SE = 0.30). Weaning weights of calves recorded in different countries were therefore considered as different traits, despite the low precision of the genetic correlation estimates. Complementary analyses within country or two by two countries confirmed these conclusions and provided for the genetic parameters used in the evaluation model. About 14 % of calves were genetically linked directly by the common use of 822 sires or maternal grand sires. Genetic links between countries were also provided by common ancestors in the back pedigree. The correlations between estimated breeding values (EBVs) of connecting bulls used in the three countries were 0.98 for FRA/GBR, 0.92 for FRA/IRL and 0.98 for GBR/IRL. Consequent re-ranking of sires between IRL and FRA was observed however for some highly connecting bulls. The main benefit of the joint evaluation was the increased choice of best seed stock provided by the comparability of EBVs between foreign and domestic bulls.