Net nutrient flux in visceral tissues of goats fed diets based on maize or wheat

The objective of this study was to investigate the effects of dietary starch sources on the net portal-drained viscera (PDV) flux of metabolites in goats fed diets based on maize and wheat, respectively. Eight 8-month-old Liuyang Black wether goats, with catheters surgically in the mesenteric vein, the portal vein and the carotid artery, were assigned to one of two diets for determination of net nutrient flux across the PDV. There were no differences (P>0.05) in plasma concentrations of glucose and ammonia-nitrogen (N) in the portal vein and carotid artery, and net PDV flux of glucose and urea-N between maize diet and wheat diet. The portal plasma urea-N concentration and net PDV flux of ammonia-N of goats fed maize diet were lower (P<0.05) than those of goats fed wheat diet. Plasma concentrations in the portal vein and carotid artery and net PDV flux of certain essential amino acids of goats fed maize diet were higher (P<0.05) than those of goats fed wheat diet. The results of this study suggested that dietary starch source could affect N absorption and utilization in goats.