Antioxidant and antibacterial properties of Salvia officinalis essential oils and their effects on In vitro feed fermentation with goat rumen liquor

The aim of this study was to investigate the chemical composition, the antioxidant and antibacterial capacities of Salvia officinalis essential oils (SOEO) as well as its effects on in vitro rumen fermentation of oat hay and methane emission using goat rumen liquor. Essential oils samples were obtained from the aerial parts of the plant and analyzed by GC-MS. The kinetics of gas production from oat hay powder containing different doses of SOEO (0, 10, 20, 40, 60 and 80 |g/mL) was conducted. A total of 29 compounds in SOEO were identified and the principal were: eucalyptol (21.08%), bicyclo hexan-3-one (16.53%) and β-pinene (11.28%). In addition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) test showed that SOEO had antioxidant capacity. The SOEO had a broad spectrum of antibacterial activity against the bacteria tested. In the present study, inclusion of SOEO at 10 µg/mL level had positive effects on in vitro OMD, ME and VFA production. However, the production of methane (CH₄) decreased in a dose-dependent manner at, the doses higher than 10 µg/mL. These findings suggested that SOEO had antioxidant and antibacterial activity and can be explored as antimethanogenic agent to control the methane production from enteric fermentation.