Studies on the movement proccss of rumen and reticulum in goats

I Observations on tracing curves of abdominal pressure and forestomach inside pressure with a kymographion

Abstract

In this paper the movements of the rumen and the reticulum in ruminants were investigated, the tracing curves of abdominal pressure and stomach inside pressure in six adult goats being the basis of the remarks.
The abdominal pressure curves (Figs. 1-4) were recorded on the smoked paper of a kymographion by a tambour which was connected to a gum-sack fixed to the left flank of unoperated normal goats. Figs. 1 and 2 show the curves recorded from the anaesthetized one. Figs. 3 and 4 show the curves recorded from untreated does during their ruminant time. Figs. 5-7 show the inside pressure curves of rumen which were recorded with a gumballoon inserted into the mediar region of rumen through the fistula of the operated bucks. Figs. 8-12 show the inside pressure curves of both thesuperior and the inferior region of rumen recorded at the same time with two gum-balloons inserted into each region. The upper curve of each figure shows pressure. change in the superior-region and the lower in the inferior. A yearling buck was operated to enclose two gum-balloons into its reticulum and rumen superior region, then Figs. 13-16 were recorded between the next day and the fourth day after the operation. Figs. 13 and 14 show the simultaneously recorded curves of reticulum (the upper curves) and rumen inside pressure(the lower curves). Figs. 15 and 16 show the curves of reticulum inside pressure (the upper) and abdominal pressure (the lower).
From these figures, the following observations are induced.
(1) The contraction of reticulum is a double movement which is finished in a short time and is followed by the alternative contractions of superior and inferior pouches of the rumen.
(2) There are two modes of contraction process in the rumen movemnt; one is the always occurring immediately after the reticulum contraction (A type movement), the other is the twice continuously alternative contractions of both rumen pouches (A B type movement) of which the first half is the same as the A type movement but the second half is of different mode.
(3) It is impossible to point out the regular relation of the order between A B type and A type movements, but in many cases the repitition of the movements of the followring order is observed:
Contraction and relaxation of reticulum-A B type movement of rumen-short time pause-contraction and relaxation of reticulum-A type movement of rumen-long time pause. If the above order is regarded as a normal cycle, the cyclic period is 40-50 seconds, that is, the frequency of rumen movement is 12-15 times per ten minutes.
(4) It is clear that the rejection of food at the time of the second mastication is caused by the reticulum contraction, and the rumen contraction does not participate in it.