Objective—To describe myoelectric activity of the spiral colon in healthy cows.
Animals—7 lactating Simmental X Red-Holstein crossbred cows.
Procedure—Cows were implanted with 7 pairs of bipolar silver electrodes (4 in the spiral colon and 1 each in the cecum, distal part of the ileum, and proximal loop of the ascending colon [PLAC]). Myo-electric activity was recorded during 4 days for each cow. Patterns were analyzed, using computer-based methods.
Results—Myoelectric activity of the spiral colon was closely associated with motility of the ileum and PLAC and showed the typical organization of migrating myoelectric complexes (MMC). The MMC in the bovine spiral colon (bcMMC) had a mean ± SD duration of 188.6 ± 30.8 minutes and was divided into 4 phases. Phases I and II lasted 11.3 ± 1.4 and 159.4 ± 33.3 minutes, respectively. Phase III (duration, 5.4 ± 1.2 minutes) was characterized by 5.2 ± 0.9 regular spindles (35.4 ± 5.4 seconds) and 1 final elongated spindle (137.2 ± 56.4 seconds). Phase III most commonly (73.8 ± 16.1%) was followed by phase IV (duration, 17.3 ± 3.6 minutes). Propagation velocity of phase III was 4.4 ± 0.5 cm/min, and 13.6% of bcMMC were incompletely propagated through the spiral colon.
Conclusion and Clinical Relevance—Myoelectric activity of the bovine spiral colon is composed of a recurring cyclic pattern similar to MMC of the small intestine. Data of colonic myoelectric activity in healthy cows will serve as a basis for studies on cecal dilatation and dislocation in cattle. (Am J Vet Res 2002;63:78–93)