This study was done to see the effects of replacing whey protein and a semi-moist diet with varying calorie content and moisture content of different forms of feed on growth performance and nutrient digestibility in weaned piglets. A total of 75 weaned piglets ([Landrace × Yorkshire] × Duroc, 28-d old, 7.17 ± 0.15 kg body weight [BW]) were randomly allocated into three treatment groups for 35 d. The three treatments were (1) Control (whey protein) by pellet, (2) Control (whey protein with energy modify) fed a semi-moisture diet by extrusion, and (3) No whey protein with higher energy semi-moisture diets by extrusion. Growth performance parameters were not changed in weaned piglets fed a semi-moist diet with replacement of whey protein and a high energy diet. The nitrogen digestibility was lower in the energy-controlled and semi-moist feed than in the control and no whey protein modified energy semi-moist feed. The semi-moist feed group contained less dry matter compared to the control group. Further, the moisture content in the semi-moist feed with whey protein was lower than that in the semi-moist feed without whey protein in the second week, and this was altered in the fifth week. The semi-moist diet with or without whey protein and the different energy diets showed similar growth performance to the control feed. However, extrusion could reduce the digestibility of semi-moist feed with whey protein. Semi-moist feed without whey protein may be provided to newly weaned piglets, but further study on this should be conducted.