In an experiment performed on three types of pig crossbreeds derived from crossing Polish Large White (PLW) x Polish Landrace (PL) sows with Duroc, Pietrain or Duroc x Pietrain boars, the effect of increased protein level (17.3 vs 15.4%) in feed mixture with low energy level (11.8 MJ/kg), and increased both protein and energy levels (to 17.3% and 12.9 MJ/kg, respectively) on fattening performance, carcass and meat quality, nutrients digestibility and nitrogen balance were studied. The best fattening performance, energy and protein utilisation were obtained from crosses of Duroc or Pietrain boars. The progeny of Pietrain boars had also the highest meat yield (65%) and the lowest carcass fat content. Increased crude protein content in the mixture did not affect significantly the live weight gains (693 vs. 711 g) or metabolisable energy conversion (36.2 vs. 35.4 MJ/kg gain), but decreased crude and digestible protein utilisation per kg of live weight gain. Increasing both protein and energy concentration in the mixture significantly (P<0.05) increased live weight gains (768 vs. 693 g).