Bacillus-based probiotic supplementation increased BW of pigs at the end of trail (P=0.012) (Table 5). Pigs on the standrad energy diet wear heavier than animals fed the lower energy diet, a near-significant trend (P=0.091). Over the whole period (28-182d), probiotic supplementation significantly improved growth rate by 3.2% (P=0.012) and F:G ratio by 1.9% (P=0.005). In addition, pigs receiving the standard energy diet exhibited 2.8% improved F:G ratio by 1.9% lower energy diet (P=0.001). No significant interactions between the energy level of the diets and probiotic supplementation were observed, so the significant improvement observed in performance with the Bacillus-based probiotic over the entire wean-to-finish period was independent from the nutritional level of the diets. The final BW, growth and F:G ratio of pigs fed the lower energy diet supplemented with the Bacillus-based probiotic were significantly improved over on the non-supplemented lower energy diet. Moreover, final BW, growth and F:G ratio of pigs were not different (P>0.05) among pigs fed the lower energy diets supplemented with the probiotic and those fed the stadard energy diet without the probiotic (Table 5).