Effect of different nitrogen source on porcine small intestinal fermentation in vitro

Abstract:

[Objective] We studied the effect of different nitrogen source on bacteria from porcine small intestine.[Methods] Digesta samples from different segments of the small intestine were inoculated into media containing enzyme-treated protein (soybean meal, rapeseed meal or fish meal) and incubated for 12 h.[Results] After incubation of jejunal and ileal microbes, the contents of ammonia and microbial crude protein increased in groups with nitrogen resources, especially the groups with rapeseed meal which had the highest increment of microbial crude protein. However, concentrations of microbial crude protein and ammonia decreased in duodenal groups. Besides, concentrations of volatile fatty acid and lactate increased in all groups, and acetate concentrations were more than 50% of the total volatile fatty acid concentration. The contents of propionate and butyrate increased in duodenal groups, whereas the contents of lactate decreased during the last four hours. However, propionate and butyrate were not changed in jejunal and ileal groups. The copy numbers of total bacteria, Firmicutes, Bacteroides and Lactobacillus increased during the experiment, but it was not significantly different between groups with different enzyme-treated protein.[Conclusion] Protein after digestion would be utilized by jejunal and ileal microbes, which mostly used to produce microbial crude protein. Duodenal microbes would utilize lactate and produce propionate and butyrate.