The primary-secondary rumen contraction and gas expulsion in sheep ( Ovis Aries)

• Published in: Comparative biochemistry and physiology. A, Comparative physiology Vol. 87; no. 4; pp. 993 - 1002
• Main Authors: Peruzzo De na Ville, Laura E, Colvin, Harry W, Backus, Robert C
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier B.V 1987; Elsevier
• Subjects: Animals; Biological and medical sciences; bloat; Electromyography; Fundamental and applied biological sciences. Psychology; gas production (biological); Gases; Gastrointestinal Motility; Muscle Contraction; Muscle, Smooth - physiology; Pressure; Rumen - physiology; rumen motility; sheep; Sheep - physiology; Stomach; Trachea - physiology; Vertebrates: digestive system; Stomach; Vertebrata; Mammalia; Motility; Digestive system; Sheep; Rumen; Eructation; Artiodactyla; Muscle contraction; Ungulata
• ISSN: 0300-9629
• DOI: 10.1016/0300-9629(87)90026-0

1. 1. Sheep rumens were insufflated with nitrogen to 5, 10, 15 and 20cm HOH pressure and sustained at each pressure for 5 min. 2. 2. Measurements included rumen motility, reticulorumen myoelectrical activity, eructation frequency and volume, and changes in tracheal pressure. 3. 3. Associated with elevated intrarumen pressure was a previously unreported type of rumen contraction on which gas expulsion occurred, the primary-secondary contraction. 4. 4. Gas expulsion volume was similar on primary-secondary and secondary contractions. 5. 5. The maximum rumen contraction rate per min was 4–5 for secondaries and 1–2 for primary-secondaries. 6. 6. Irrespective of the sustained initial pressure, resting intrarumen pressure was reached within 5 min.