A stringent test for the artificial rumen

Abstract

In each of three experiments the acetic, propionic, and butyric acids in the rumen of a sheep were labelled with ¹⁴C and a sample of the rumen contents was removed to an artificial rumen so that fermentations of the same substrates could be conducted simultaneously in vivo and in vitro. The in vitro fermentations were carried out in a specially designed artificial rumen of the "permeable" type in which the volume of the contents was kept constant while a continuous supply of artificial saliva was introduced. The relationships between the specific activities of the volatile fatty acids during a period of 2 to 3 hr indicated that the relative rates of formation of the acids were similar in the two systems, although in each experiment the fermentation appeared to proceed more slowly in vitro. It is considered that the procedure constitutes a stringent test for the correct functioning of an artificial rumen.