Arterial blood flow to the ruminant stomach

Abstract

In seven of eight adult bovine females, increase in right ruminal or omasal artery flow was seen upon feeding. This increase continued beyond the act of feeding and was independent of weight-volume and motility change. Blood flow recorded from posterior mesenteric or hypogastric arteries did not show increase on feeding. Feeding under conditions where rumen fermentation was minimal limited the increase in ruminal blood flow to the period when the animal was eating. The passive transfer of feed into the rumen under these circumstances gave no blood flow stimulation. In five adult animals, an increase in CO2 tension within the reticulorumen increased blood flow. Acetate, propionate, and butyrate also stimulated blood flow. Concentration increments of the three organic acids showed increase in amount absorbed per unit time, but no regular relation to blood flow. A method of studying confined volumes is described.