A Comparison of the All-Glass, Semipermeable Membrane, and Continuous Flow Types of Apparatus for In Vitro Rumen Fermentations1,2

Abstract

Summary A comparison was made of three different types of apparatus commonly used for in vitro rumen fermentation studies. The types compared were the all-glass, the semipermeable membrane, and the continuous flow. Purified wood cellulose and several different types of hay were used as substrates, with cellulose digestion, total volatile fatty acid production, and ammonia nitrogen production (for the hay samples only) being used as criteria of microbial activity. No major differences were found between the different types of apparatus; however, the all-glass apparatus appears to be advantageous because of its simplicity.