Evaluation of different essential oils in modulating methane and ammonia production, rumen fermentation, and rumen bacteria in vitro

• DOI: 10.1016/j.anifeedsci.2016.02.008
• Publication Date: 2016-03-14T18:35:21Z
• Authors: Gabriella Cobellis; Massimo Trabalza-...; Maria Carla Marco...; Zhongtang Yu
• Keywords: Prevotella

Abstract Various essential oils (EO) have been individually evaluated to mitigate methane and ammonia production by rumen microbiota. Interactions between EO can affect their potency but such interactions largely remain unexplored. In the present study, EO from oregano, rosemary, Ceylon cinnamon, cinnamon leaves, cinnamon bark, dill seeds, and eucalyptus were chemically characterized and then evaluated in vitro , both individually (at 1.125 ml/L culture) and in three-way EO combinations (at total EO 0.8 ml/L, equal ratio), for their effects on fermentation, methanogenesis, ammoniagenesis, and bacteria and archaea. All the EO and their combinations decreased production of total gas (P Prevotella spp. (P . The EO combinations significantly decreased the abundances of archaea (P , and select groups or species of different rumen bacteria to different extents. Changes in bacterial and archaeal communities in response to several EO combinations were also shown by DGGE analyses. Combination of EO from Ceylon cinnamon, dill seeds, eucalyptus, and probably others, at low concentrations may be a practical approach to mitigate methane emission and nitrogen excretion from ruminant without adverse effect on feed digestion or fermentation.