摘要Background:This study aimed to develop a combined model to quantify the net ab-sorption of volatile fatty acids(VFA)in the large intestine(LI)of pigs.Methods:Fifteen female growing pigs(Duroc×Large White×Landrace)were ranked by body weight(30±2.1 kg)on day 0 and assigned to one of three treatments,namely the basal diet containing different crude fiber(CF)levels(LCF:3.0%CF,MCF:4.5%CF,and HCF:6.0%CF).The pigs were implanted with the terminal ileum fistula and the cannulation of the ileal mesenteric vein(IMV),portal vein(PV),and left femoral artery(LFA)from days 6 to 7.[13 C]-Labeled VFA and P-aminohippuric acid were constantly perfused into the terminal ileum fistula and the cannulation of the IMV(day 15),re-spectively.Blood samples were collected from the PV and the LFA during perfusion(5 h),and LI samples were collected.Results:The net flux of[12 C]-acetic acid in the PV was greater for LCF versus MCF(p = 0.045),but no difference was observed in the net flux of[12 C]-propionic acid(p = 0.505)and[12 C]-butyric acid(p = 0.35)in the PV among treatments.The deposi-tion of[12 C]-acetic acid in the LI was greater for LCF versus MCF(p = 0.014),whereas the deposition of[12 C]-propionic acid(p = 0.007)and[12 C]-butyric acid(p = 0.037)in the LI was greater for LCF versus HCF.Conclusions:In conclusion,this pig model was found conducive to study the net ab-sorption of VFAs in the LI,and LCF had more net absorption of VFAs in the LI than MCF and HCF.