Saturday, April 2, 2011
9:13 PM

Reticuloruminal Motility

Reticuloruminal Motility





An orderly pattern of ruminal motility is initiated early in life and, except for temporary periods of disruption, persists for the lifetime of the animal. These movements serve to mix the ingesta, aid in eructation of gas, and propel fluid and fermented foodstuffs into the omasum. If motility is suppressed for a significant length of time, ruminal impaction may result. A cycle of contractions occurs 1 to 3 times per minute. The highest frequency is seen during feeding, and the lowest when the animal is resting. Two types of contractions are identified:
 

  Primary contractions originate in the reticulum and pass caudally around the rumen. This process involves a wave of contraction followed by a wave of relaxation, so as parts of the rumen are contracting, other sacs are dilating.
  • Secondary contractions occur in only parts of the rumen and are usually associated with eructation.
The animation below is based on data collected by radiographing sheep (Wyburn, 1980) and should impart at least some appreciation of the complexity of ruminal motility. Although shown much faster than in life, the major reticuloruminal contractions are timed appropriately. Note the movements which bring the gas bubble (stippled area) forward to the esophagus for eructation.






0 التعليقات: