Introduction. Pig industry has been evolving in the obtaining of early genetic lines, with better food conversion indexes and leaner meat. Additional to the genetic improvement, non-nutritional additives have been developed, with the capacity of increase the production performances. Within this group of additives we have the Ractopamine compound. Materials and methods. A total number of 42 pigs (83,4± 0,22 kg) were used during 28 days, in which the effect of two levels of Ractopamine were evaluated in the diet (0 and 10 ppm) and three levels (lysd) of lysine (0,65; 0,80 and 0,95) over the daily food consumption (DFC), the daily increase of weight (DIW), the difference of dorsal fat (P2) (DDF), depth of the chop, area of the chop eye (ACHE), lean fat free tissue (LFFT), and daily increase of lean fat-free tissue (DILFFT). Results. For DIW, DDF, ACHE, LFFT and DILFFT variable, we found high statistic difference among treatments, obtaining higher rates in the animals treated with with the maximum Lysd level and Ractopamine in their diets. Conclusion. Adding 10 ppm of Ractopamine in the diet, significantly increased the DILFFT. This fact can be a positive aspect seen in the quantity of lean pork meat cuts.