Rumination may be stimulated by a recording balloon in the reticulum of the sheep.

Rumination activity was recorded by three different methods in five sheep which had been fasted for 12 hours. When a balloon on plastic tubing was passed into the reticulum via a rumen cannula there was significantly more rumination recorded during the subsequent three hours than when rumination was recorded by registering jaw movements alone. The greater part of this stimulation occurred in the first half hour of recording. There was a significantly greater effect when the tubing to the reticulum balloon was stiffened with wire. Care is needed in comparing rumination times determined by different procedures.