Effects of Fasting and Sedation on Gastrointestinal-Tract Function in 2 Potoroine Marsupials

Abstract

Radiographic techniques were used to follow the movement of barium sulfate given orally, either as a suspension or incorporated into feed pellets, through the gastrointestinal tract of two potoroine marsupials, Aepyprymnus rufescens, the rufous rat-kangaroo; and Potorous tridactylus, the long-nosed potoroo. Compared with previously reported results from fed animals, fasting for 12-15 h delayed the passage of contrast medium into the small intestine, but sedation with ketamine hydrochloride visibly increased gastrointestinal tract activity and significantly reduced retention times of contrast medium in the stomach. A daily cycle of ingesta movements within the potoroine stomach, consequent upon the discontinuous feeding pattern and nature of the diet of these small marsupials, is proposed. In this proposal the sacciform region of the forestomach plays a primary role in storage of ingesta for later digestion in the intestine, and fermentative digestion of fibre is of secondary importance.