At a pig progeny testing station growth and production traits were examined in 38 pigs (20 animals of Large White /LW/ breed, 18 animals of Large White breed – paternal line /LWp/) using methodical instructions for performance testing and testing of purebred progeny. Richards function was applied to calculate the parameters and characteristics of growth curves that document a change in the production type of both breeds towards a markedly meat type in
the course of 10 years. The changes were refl ected in an increase in the lean content on average by 3% in LW breed and by 2.7% in LWp breed. This positive trend is documented by the results measured by in vivo and post mortem methods. Both groups of methods of measuring lean percentage provided a good coincidence of the results; therefore the instrument SONOMARK-100 can be recommended for an early estimation of breeding value in growing pigs.
