Fifty-four pigs of three genotypes, 25% Polish Large White, 25% Polish Landrace (maternal genotype) and 50% Duroc or 50% Pietrain or 25% Duroc plus 25% Pietrain (paternal genotype) were fattened from 29 to 110 kg body weight. The animals were fed ad libitum one of three diets containing MJ ME and g crude protein in the following amounts: 12.3 and 156; 12.3 and 170; 13.4 and 173 per kilogram of diet. Increasing the concentration of protein and energy increased efficiency of feed conversion and ME per body gain, regardless of the type of crossbred. Genotype x nutrition interaction (P≤0.05) on the meat content in carcass was found. Increasing the protein as well as both protein and energy contents in the diet increased the meat content in carcass of pigs with 50% Pietrain genes, while no such response was found in the other genotypes.