This thesis examined effects of dietary supplementations (0.75%) of the prebiotics of retrograded resistant cornstarch, fibersol-2 and inulin, and oat β-glucan in replacing feed antibiotics on growth performance, plasma urea concentrations, total tract dry matter (DM) and lactose digestibility, fecal scores, proximal jejunal and serum alkaline phosphatase (AP) kinetics and large intestinal fermentation in weanling pigs fed corn and soybean meal-based diets. There were no differences (P > 0.05) in the growth performance, plasma urea concentrations, DM and lactose digestibility and the volatile short-chain fatty acid concentrations in the cecal and fecal samples among the treatment diets. Dietary lactose was completely digested in the weanling pigs. Supplementations of fibersol-2, inulin and β-glucan significantly affected some of the jejunal and serum AP kinetics. In conclusion, lactose was a highly digestible carbohydrate and dietary supplementations of the three prebiotic and β-glucan at 0.75% had little effects on growth performance and plasma urea concentration but might affect gut and the whole body health status via influencing the AP detoxification kinetics in the weanling pigs.