A corn and soybean oil meal ration fortified with dehydrated alfalfa meal, meat and bone scraps, vitamins, APF supplement, iodized CaCO3, steamed bonemeal, and salt was fed to replicated lots of growing-fattening pigs. This ration was supplemented with a mineral mixture at 3 levels, namely 0.05, 0.10 and 0.15%. When the mixture was added at 0.05%, it contributed 35.0 ppm. of Fe, 29.5 ppm. of Mn, 2.4 ppm. of Cu, 0.8 ppm. of Co, and 2.2 ppm. of Zn. The means of the avg. daily gains of both replicates for the pigs fed the respective levels of mineral mixture were 1.72, 1.77, 1.80 and 1.74 lbs. An analysis of variance showed the gains were significantly influenced (P = 0.05) by the level of trace minerals fed and the regression of avg. daily gain on the level of minerals was curvilinear. Trace minerals fed to sows during gestation and to sows and litters during lactation may have a subsequent influence on the growth response of the pigs from weaning to market. The chemical analyses of the rations would indicate that the improved performance from the addition of the different minerals was due to Cu, Mn, and/or Co. The differences found in feed efficiency and in hemoglobin readings were not statistically significant.