Using three trained, fistulated goats in standing and recumbent positions, ruminal gas accumulating in the top of the dorsal sac was collected and measured during resting and ruminating activities. Collectible gas accumulation (CGA) rates were higher during rumination than during rest but were reduced below resting rates during ruminal atony induced by administration of atropine. Three conditions which resulted in abrupt increases in CGA rates were: 1) ruminal contractions following a period of atony, 2) changing from rest to rumination, and 3) vigorous somatic movements. At an intraruminal pressure of 15 cm water below atmospheric pressure, ruminoreticular cyclic frequency, secondary ruminal contraction frequency, and the ratio of the number of secondary to primary ruminal contractions were reduced. The observations indicate that reduced eructation rates during periods of rest result from a reduction in gas accumulation in the dorsal rumen because of a temporary storage of gas at other sites.
- stomach motility
- ruminoreticular motility
- ruminal gas collection
- Copyright © 1965 by American Physiological Society