Data were analyzed using PROC MIXED of SAS (SAS Inst. Inc. Cary,NC, USA). Barrow was considered the experimental unit. Obaervations from every barrow were included in data analysis, as none were removed from the trial. The model included the main effects of dietary treatment, experimental period, and dietary treatment x experimental period interaction. Block was considered random. Least squans were considered significant when P< 0.05.