Czech Fleckvieh (CF), Charolais (CH) and crossbred CF x CH were fattened up and fed ad libitum two mixed diets: MS (maize silage) and LCS (legume-cereal and lucerne silages). The CF bulls consumed more dry matter (DM) of feed daily than the CH bulls andgained weight less efficiently than the other bulls. Likewise, the killing-out percentage was lower. The CH bulls received a higher score for carcass conformation and a lower score for carcass fatness than the CF bulls, had lower proportions of kidney and cod fats than the other bulls, and produced the highest percentage of high-priced meat and the lowest percentage of separable fat. CH bulls were superior to the other bulls in most of the traits observed. The intensive MS diet increased average daily gains, reduced the time needed to achieve the slaughter weight, and improved the feed efficiency