Abstract
Three experiments were conducted to make clear the function of ingestatransfer in the omasum of calves. In Experiment l, ingesta transfer from the reticulumto the omasum was studied. An elastic tube was inserted into the reticulo-omasal orificethrough the omasum fistula. Outflow of ingesta from the reticulum through the tube wasobserved immediately after the second contraction of the reticulum. Furthermore, simultaneous pressure recording in the reticulum, rumen and omasal canal showed a rapid, pronounced drop in pressure of the canal at the time of the second contraction of tlaereticulum.Nut Experiment 2, auscultation on the body surface of the omasum was carried otzt.Flowing liquid sounds began to be heard periodically at 4-6 weeks of age. They wererecognized immediately after contraction of the omasal canal and about 12 seconds aftercontraction of the reticulum, although no sounds coutld always be heard in each reticularcycle. In Experiment 3, ingesta transfer from the omasum to the abomasum was studied.FIOW of ingesta into the abomasum was recognized about 12 seconds after contraction ofthe reticulum by visual inspection through the abomasum fistula. From the results ofExperiments 2 and 3, it can be considered that the flowing liquid sounds are attributableto the ingesta transfer from the omasum to the abomasum by the contraction of theomasal canal.
