The effect of dietary crude protein concentration and inulin supplementation on nitrogen excretion and intestinal microflora from finisher pigs.

摘要

A 2x2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n=4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P<0.01), faecal N (P<0.01) and total N (P<0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P<0.05) and decreased urine: faeces N ratio (P<0.05) compared to the inulin free diets. There was no significant effect (P>0.05) of dietary treatment on N retention. There was an interaction (P<0.05) between dietary CP concentration and inulin supplementation on caecal E. coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E. coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E. coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P<0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E. coli at high CP concentrations..