As double-muscled Belgian Blue (BB) and Piemontese (PIEM) breeds are heavily selected for different objectives (the former mainly for muscularity, the latter for ease of calving), the aim of this study was to compare sexual dimorphism in 56 crossbred young bulls and heifers obtained from dairy cows mated to bulls of the two beef breeds. Young PIEM- and BB-sired bulls had similar fattening performances and beef traits, although the BB crossbreds were slightly more muscular. Otherwise, the BB-sired heifers exceeded the PIEM-sired heifers in growth rate (1.12 vs. 0.98 kg/d), feed efficiency (0.129 vs. 0.121 kg/kg DM), increases in muscle scores (1.45 vs. 0.98 SEUROP scores) and carcass yield (0.612 vs. 0.605), but not in fatness, retail cut proportions and meat quality traits. Sexual dimorphism is, therefore, less distinct in BB than in PIEM crossbreds. In conclusion, BB sires are to be preferred for “product quality”, and PIEM sires for “process quality”, on account of welfare and ethical issues.

由于双重肌肉比利时蓝（BB）和皮埃蒙特（PIEM）品种是出于不同目标而大量选择的（前者主要是为了肌肉，后者是为了容易产犊），所以本研究的目的是比较56个杂种幼年的性二态性。从与这两个牛肉品种的公牛交配的奶牛获得的公牛和小母牛。尽管BB杂种的肌肉稍强一些，但年轻的PIEM和BB代公牛的育肥性能和牛肉性状却相似。否则，BB型小母牛的生长速度（1.12比0.98 kg / d），饲料效率（0.129 vs. 0.121 kg / kg DM），肌肉得分增加（1.45 vs. 0.98 SEUROP得分）要超过PIEM母牛。 ）和car体产量（0.612 vs.0.605），但脂肪，零售切成比例和肉质特性方面则不然。因此，BB中的性二态性不如PIEM杂种。总之，出于福利和道德问题的考虑，BB产品应优先选择“产品质量”，PIEM产品应优先选择“工艺质量”。