During the grower period (70–120 d), the probiotic improved growth rate by 11.2% (P < 0.001) and F:G by 8.6% (P < 0.001)(Table 4). During this period, there was an interaction between the effects of the probiotic and dietary energy (P = 0.005) with pigs offered the lower energy diet without the probiotic exhibiting a considerably higher F:G than pigs on all other treatments.During the finisher period (70–182 d), probiotic supplementation impaired F:G (P = 0.047). No significant differences betweenthe levels of energy were observed. For the overall fattening period (70–182 d), pigs receiving the Bacillus-based probioticgrew 2.6% faster (P = 0.061) and exhibited 2.1% improved F:G ratio (P = 0.019) than non-supplemented animals. Also pigs onthe standard energy diet exhibited 3.0% improved F:G ratio compared to pigs receiving the lower energy diet (P = 0.001).