The sample of 954 slaughter pigs of common hybrid combinations ((Topigs x CL) x PN) from chosen agricultural enterprise were put into the field test. The fattening was realised in five separated fattening cycles (1 to 5). Barrows and gilts were equally represented in this sample. The pigs were slaughtered in selected slaughterhouses and graded regarding to the SEUROP-system with authorized devices. The average lean meat content reached the values from 56.5 +/- 0.216% (cycle 5) to 60.16 +/- 0.175% (cycle 2). From te whole sample (n = 954) the grading class S was represented by 257 individuals (27%), the class „E“ by 581 carcasses (61%) and the class U by 106 of them (11%), that means these three grading classes contained more than 99% of carcasses. From these reasons it’s necessary to use the sub-classes (range of 1%). The average carcass weight reached values between 84.04 +/- 0.529 kg (cycle 5) and 99.89 +/- 0.605 kg (cycle 1). The influence of the carcass weight (x) on the lean meat content (y) was presented with the formula y = -0.0262x + 60.648. On the base of a model price mask were the farm prices observed, separately for every fattening cycle. It’s advisable to use the sub-classes in range of one percent of lean meat.