Endogenous praecaecal and total tract losses of nitrogen in pancreatic duct-ligated minipigs.

The pancreatic duct-ligated minipig (PL) is an established model of pancreatic exocrine insufficiency (PEI) with a significant decrease of nutrient digestibility. This study aimed to quantify and compare endogenous losses of nitrogen (N) (ileal and faecal) in minipigs receiving an almost N-free diet. Altogether, 12 Gottingen minipigs (7 PL and 5 control animals) fitted with an re-entrant ileo-caecal fistula were used. In Study 1, ileal digesta was collected over a period of 12h on seven consecutive days, including one 24h collection, when animals were fed a diet containing 0.49gN/kg dry matter (DM). In Study 2, faeces were collected for 10 consecutive days. In Group PL, the amount and DM content of ileal digesta were higher (p<0.05), while N concentration was lower than in the Control. The ileo-caecal N flux [g/kg DM intake] was about 2.5 times higher in Group PL (5.47 +/- 1.15) than in the Control (1.91 +/- 0.59) (p<0.05). The amount of faeces did not differ, but faecal N losses were higher in Group PL (p<0.05). Endogenous faecal N losses [gN/kg DM intake] of the Control group (1.17 +/- 0.72) were comparable with earlier studies, while those of Group PL were 2.6 times higher (3.09 +/- 1.34). In contrast, urinary excretion of N did not differ between the Control and Group PL. In conclusion, PEI caused markedly increased endogenous N losses. Therefore, the impact of reduced digestibility of nutrients on endogenous N losses might be relevant for apparent protein digestibility rates and should be taken into account.