The present study was conducted to determine the mechanism by which nitrogen (N) availability is improved by fructo-oligosaccharide (FOS) in guinea pigs. Adult male guinea pigs were fed a commercial pellet diet (50g/day) with either 5% glucose or 5% FOS for 7 days in individual metabolism cages. After 7 days of feeding the diet, 15N-urea was administered intravenously 1h before slaughter under anesthesia. The amount and concentration of total, protein, bacterial, ammonia and urea N and the 15N atom % excess were measured in blood, liver, gut contents and urine. The 15N atom % excess of total and protein N, and the amount of total, protein and bacteria N and 15N in the cecum were significantly increased by the consumption of FOS. Furthermore, the concentration and amount of short-chain fatty acids were significantly increased by the consumption of FOS. In contrast, the amount of urinary 15N was significantly decreased by the consumption of FOS. These results suggest that consumption of FOS increases transfer of blood urea N into the large intestine for bacterial N synthesis, which is subsequently re-absorbed by cecotrophy, and contributes to the increase of N utilization in guinea pigs.
- Guinea pig
- Nitrogen utilization
ASJC Scopus subject areas
- General Agricultural and Biological Sciences