Modificación de la fermentación ruminal in vitro para mitigación de metano mediante la adición de aceites esenciales de plantas y compuestos terpenoides

Essential oils from plants are volatile aromatic compounds, mainly terpenoids, phenylpropanoids; monoterpenes, sesquiterpenes, and alcohols, these present a wide range of antimicrobial and antioxidant activity, so the addition of essential oils of clove, eucalyptus, mint, rosemary, oregano, and cinnamon can modify ruminal fermentation by reducing the population of bacteria producing methane and thus have a reduction in the production of this gas. The objective of this work was to evaluate different essential oils and terpenoid compounds to improve ruminal fermentation and the production of volatile fatty acids, attenuating the generation of methane. The chemical composition (terpenoids) of the oils, as well as volatile fatty acids (VFAs), were determined by gas chromatography. For in vitro digestibility, the in vitro gas production technique was used, and the ruminal liquid was used. Methane was inferred from the concentration of VFAs. It was found that all the essential oils presented each one of the terpenoids in different concentrations, reporting the highest concentration of carvacrol in the essential oil of clove (303 mg mL-1) and oregano (1.20 mg mL-1); terpinene was presented in greater quantity in the essential oil of peppermint (4.83 mg mL-1); for peppermint and rosemary oil, linalool was higher and for limonene, the highest concentration was in eucalyptus oil (449 mg mL-1) and rosemary (12.42 mg mL-1). For gas production in digestibility, eucalyptus essential oil at a dose of 0.3 presented 176 mL g-1 DM. For in vitro digestibility, rosemary oil in high dose (0.6 mL) presented the best ruminal fermentation since it had better methane mitigation (716.83 mM/L) without negatively affecting the concentration of VFAs (acetate, 1892.2; propionic, 526.14; butyric, 24.99 mM/L), as well as terpenoids like thymol, linalool, and limonene in high doses. It is concluded that the best in vitro ruminal fermentation with methane mitigation was observed with rosemary oil and the terpenoid compounds were thymol, linalool, and limonene in the high dose.