Eructation, regurgitation, and reticuloruminal contraction in the American bison

¹ Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota

Simultaneous pressure changes in four compartments of the reticulorumen of two young, female bison prepared with rumen fistulas were recorded during eating, ruminating, resting, and insufflation with nitrogen gas. Frequency, magnitude, and duration of contractions were measured in a series of 26 experiments during which the bison were tied in a stanchion. From these measurements it was concluded that reticuloruminal motility of American bison is similar to that of domestic cattle. Eructation occurred almost always during contraction of the posterior dorsal blind and dorsal sacs of the rumen. The frequency of eructation was similar to that which was reported previously in cattle and white-tailed deer. During rumination there was an extra reticular contraction during which regurgitation occurred.

Key Words: reticuloruminal motility • gastric motility in bison • pressure changes in the stomach of bison • bovine gastric motility • rumination in bison • buffalo (bison), stomach contractions of

Submitted on August 7, 1964