During the pre starter period (28–42d), there were no treatment effects on growth performance.For the starter period (42–70d) pigs on the probiotic treatments grew significantly faster and tended to have a better feed:gain (F:G) than their control counterparts. During thesame period pigs offered the standard energy diet exhibited significantly better F:G thanthose offered the lower energy diet. During the grower period (70–120d), the probiotic significantly improved growth rate by 11.2% and F:G by 8.6% with the proportional changein F:G being much higher for pigs offered the lower energy diet. During the finisher period(120–182d), the probiotic had a negative effect on F:G (P = 0.047).