The aim of this study was to investigate young pig fattening and meat quality due to the varying formation intensities in early ontogenesis and two genotypes based on the melanocortin receptor 4 (Mc4r) gene. To calculate the correlations between traits and the economic efficiency of using animals of experimental groups in industrial complex conditions, the assessment of animals for fattening and meat quality examined the following characteristics: average daily live weight gain during the control fattening period in grams; age of reaching 100 kg live weight in days, chilled carcass length in centimetres; length of the bacon half of the cooled carcass in centimetres; lard thickness at the thoracic vertebrae T6-T7 in
millimetres.