Essential oils affect populations of some rumen bacteria as revealed by microarray analysis

Origanum oil (ORO), garlic oil (GAO), and peppermint oil (PEO) were shown to effectively lower methane production, decrease abundance of methanogens, and change abundances of several bacterial populations important to feed digestion in vitro. In this study, the impact of these essential oils (EOs, at 0.50 g/L), on the rumen bacterial community composition was further examined using the recently developed RumenBactArray. In vitro rumen mixed cultures (three replicates) received 0.50 g/L each EO in the present study. The control culture (three replicates) that did not receive EO was included in parallel.