Estimating Gastrosplenic Blood Flow and Volatile Fatty Acid Absorption from the Forestomachs of Calves

Abstract

Blood flow from the coeliac artery, which is distributed to the rumen, reticulum, omasum, abomasum, and the spleen, and eventually passes through the gastrosplenic vein, was estimated in seven calves anesthetized with nembutal. The abdominal cavity was entered through an incision along the line of the 12th rib. Erythrocytes tagged with P32 served as markers, and the isotope dilution method was used to determine the rate of blood flow. The tagged erythrocytes were injected into the coeliac artery and collected from the gastrosplenic vein. The first radioactivity appeared in the gastrosplenic vein 1 to 2 sec. after the injection, and the maximum concentration occurred in 12.4 sec. The average time required for all the injected, labelled erythrocytes to pass through the gastrosplenic vein was 31.3 sec. The mean rate of gastric blood flow was calculated to be 764 ml. per minute per 100 lb. of body weight. Based on the analysis of serial blood samples obtained from a calf fitted with a polyethylene catheter into the gastrosplenic vein, it was calculated that approximately 63 g. of acetic and 25 g. of propionic acid were absorbed for each pound of dry feed (a 2:1 mixture of alfalfa hay and grain concentrate) consumed during a 24-hr. period. © 1958, American Dairy Science Association. All rights reserved.