山羊の第一胃第二胃の運動機構について

In this paper the movements of the rumen and the reticulum and the destination of swallowed food in ruminants were investigated by X ray observations and indirect photographing with four we anling kids. Prior to the experiments, their rumen contents were washed out and they were crammed down with contrast-forming gruel made of starch and barium sulfate.<br>Fig. 1 shows a series of X ray photographs of the fore-stomach taken indirectly from the left side of the animal continuously at three seconds intervals. The intervals between two photos were as follows:<br>Photo No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15<br>Interval 3 3 3 3 9 24 3 3 6 9 3 3 3 6<br>(Sec, )<br>The following facts were observed:<br>(1) The reticulum contracts rapidly in two steps and casts out its content into the rumen. The contraction of the reticulum is so strong that it seems to disappear into the rumen at the maximum contraction stage. (Fig. 1. No. 6.)<br>(2) As soon as the reticulum relaxes, the rumen begins to contract slowly in a peristaltic manner. The order of the rumen movement is as follows: contraction of the dorsal pouch, expansion of the ventral caudal blind pouch-relaxation of the dorsal pouch, contraction of the ventral caudal blind pouch -recovery of the original form -pause. The authors call the above movement A type. (Fig. 1. No. 3-No. 6)<br>(3) After the long time pause, the reticulum begins to contract, and the A type movement of the rumen follows again. (Fig. 1, No. 7-No. 11) Then, without a pause and reticulum contraction, the secondary rumen movement occurs which is of quite different sort than the A type movement. (Fig. 1, No. 12-No. 15) The authors call it B type. It is significant that when the dorsal pouch contracts a fist-size knob appears on the upper wall of the ventral caudal blind pouch and runs along the curvature of the blind pouch toward the ventral forward pouch like a wave motion. This observation suggests that the contents of the caudal blind pouch may be ejected, by this movement.<br>(4) The X ray observation of the forestomach movement order agrees with the results of the kymographic studies as follows: reticulum movement -A B type movement of rumen -short time pause -reticulum movement -A type movement of rumen -long time pause.<br>(5) The solid food which has been eaten is swallowed into the forward part of the dorsal pouch through the esophageal groove, and enters into the reticulum when it relaxes, then it is cast out far back-ward into the rumen when the reticulum contracts.<br>(6) The fluid content of rumen may pass into the omasum and abomasum through the connecting opening without rumination.<br>(7) It was ascertained that when the weanlings sucked milk containing some barium sulfate from a nipple bottle, the swallowed milk passed directly into their omasums and abomasums. However, when they drank the same milk from a pail, the barium milk entered entirely into their rumens and reticulums (Fig. 3 shows the former case and Fig. 4 the latter case. The photographs were taken from the right side of the animals indirectly.)