Technique for Measuring Eructated Gas in Cattle

Abstract

A technique, involving tracheal transection, to determine the frequency and amplitude of eructation, was developed with 7 steers and 2 cows. To measure the volume of the eructations, a mask was installed on the animal''s muzzle and a cannula inserted in the anterior end of the transected trachea. Tubing connected the mask and cannula to a spirometer. In this type of preparation most, if not all, of the eructated gas escaped via the anterior trachea. The volume of gas evolved in the rumen (less that absorbed through the rumen wall) was measured in 10 trials with the eructation technique. These values compared favorably with those recorded from 4 trials using a method where the gas was aspirated directly from the rumen. For the comparison, 2 steers and diets of alfalfa hay, oat hay, and alfalfa tops-oat hay were employed. The rumination reflex appeared to be unimpaired.