Calculations
Individual barrows were considered the experimental units. GE intake for each barrow was calculated by multiplying total dry matter (DM) intake over the four day collection period be feedstuff GE content determined from isoperibol bomb calorimetry analysis. Diet digestible energy (GE) was calculated by subtracting fecal energy from GE. Diet metabolizable energy (ME) was calculated by subtracting urinary energy from DE. Apparent DE and ME of the corn-soybean product were extrapolated by difference from that of the basal diet, with basal diet DE and ME subtracted from the DE and ME of the CSOY diet [11,12].
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.