Observations on the act of eating in cattle

Abstract

In any consideration of normal reticulo-ruminal function the act of eating is likely to play a highly important part. When food is eaten, or shortly afterwards, critical events occur in the reticulo-rumen such as the maximum daily inflow of saliva and water inducing the minimum concentration of micro-organisms, the sudden change from the least to the greatest weight and volume of the contents and the greatest daily change in the composition of the contents. The primary object of this paper is to present relevant information on these matters obtained, sometimes incidentally, in a number of experiments. Observations have been grouped under four headings : saliva production, the rate of movement of the jaw, the rate of contraction of the reticulum and the change in the amount of digesta present in the reticulo-rumen. As a secondary object the findings have been examined to see whether they throw light on the mechanism determining the point at which a cow stops eating food which has been offered ad lib.