In Vitro Volatile Fatty Acid Production from Various Feeds by Bovine Rumen Microorganisms1

Abstract

Several common dairy feeds were compared based on their 12-hour production of VFA in vitro. The in vitro method used yielded reproducible results between replicates. Urea consistently increased volatile fatty acid production in vitro regardless of the substrates used, although in subsequent in vivo experiments it increased VFA production only slightly. Fresh hand-clipped legume mixed grass caused a greater VFA production than did legume hay. The grass markedly depressed propionic acid formation, however, compared to hay. Molasses consistently decreased acetic acid production. Beet pulp significantly increased acetic acid production and corn meal increased propionic acid production.