Genetic correlation estimations between artificial insemination sire performances and their progeny beef traits both measured in test stations

In France, beef traits of artificial insemination (AI) beef bulls are impro ved through the sequential selection for their own performances and for the ir male progeny performances, both being recorded in test stations. The eff iciency of such programmes mainly depends on the genetic correlations betwe en sire performances and progeny beef traits. Such correlations were indepe ndently estimated, using the multivariate REML (restricted maximum likeliho od) method in a Limousin and a Charolais programme. In both breeds, high ge netic correlations were observed between sires and progeny analogous morpho logy scores (from 0.64 to 0.82). Genetic correlations estimated between sir es and progeny growth (from 0.41 to 0.70) were lower probably due to the di fference of diet in central and progeny stations. Correlations between sire muscling scores and progeny skeletal frames (and vice-versa) were negative (from -0.05 to -0.58). The genetic correlations of sire traits with progen y dressing percentage (DPp) and carcass fatness score (CFp) were only low t o moderate. These results show that the selection of bulls at the end of pe rformance testing in test stations may be efficient in improving progeny gr owth and morphology. However, such a selection is insufficient in improving their dressing percentage and carcass composition.