Effects of dietary Greek oregano (Origanum vulgare ssp. hirtum) supplementation on rumen fermentation, enzyme profile and microbial communities in goats

Abstract

This study was conducted to examine in vivo long-term effects of dietary dried oregano (Origanum vulgare ssp. hirtum) whole plant on rumen fermentation, enzyme profile and microbial communities. For this purpose, eight healthy, adult, non-lactating Alpine goats were kept in tie stalls equipped for individual feeding and randomly divided into two homogeneous groups: one fed 0.6 kg of a concentrate mixture and 0.6 kg of wheat straw without any supplementation and served as control group (CON) while the other group (OR) fed the same diet of CON but supplemented with 20 g of dried oregano plants (OPs) to provide daily dosage of 1 ml of essential oil (EO) per animal. The experimental period lasted 69 days and individual rumen fluid samples were obtained every 2 weeks at 0 and 4 hr after feeding. The results showed that dietary supplementation with OPs increased the protease activity (p < .001) and ammonia concentration (p < .05) in the rumen. Among the studied microbial populations, Peptostreptococcus anaerobius (p = .028) and Clostridium sticklandii (p < .001) were found to be the most sensitive to oregano at the current dosage. Furthermore, the total methanogen population significantly decreased (p < .05). It is concluded that a long-term dietary administration of OPs can suppress specific rumen micro-organisms and modify rumen fermentation favourably at least by means of suppressing methanogens.

Effect of dried oregano (Origanum vulgare L.) plant material in feed on methane production, rumen fermentation, nutrient digestibility, and milk fatty acid composition in dairy cows

“…Our results support those of Hristov et al (2013), who did not observe changes in total VFA concentration, A:P ratio, or molar proportions of acetate and propionate. Furthermore, unaltered VFA molar proportions were reported previously (Wang et al, 2009;Tekippe et al, 2011;Kolling et al, 2018;Paraskevakis, 2018). The main effect of feeding low EO oregano on rumen fermentation was a decline in microbial CP synthesis in Exp.…”

Evaluation of origanum oil, hydrolysable tannins and tea saponin in mitigating ruminant methane: In vitro and in vivo methods

“…The results of ORO linearly reducing in vivo CH 4 emission supported our in vitro observations, especially to 20 and 40 ml/kg additive levels. This result was consistent with the research of Paraskevakis ( 2018 ), who found that 1 ml/day ORO suppressed specific rumen microorganisms in goats by inhibiting methanogens activity. Benchaar ( 2020 ) reported that 50 mg/kg DM of ORO had no effect on the total‐tract apparent nutrients digestibility and enteric CH 4 emission of dairy cow.…”

“…As the main constituents of ORO, carvacrol and thymol have similar chemical structures and are verified to have valid antimicrobial activities (Patra & Yu, 2015 ). The linear reduction of in vitro CH 4 and CO 2 emissions may be directly related to the specific inhibition by carvacrol and thymol on Prevotellaceae , Lachnospiraceae and Ruminococcaceae (Paraskevakis, 2018 ; Patra & Yu, 2015 ). In addition, the 40 mg/kg ORO significantly reduced CH 4 by 35.98%, and 20 and 40 mg/kg ORO significantly inhibited CO 2 by 46.16% and 55.85% compared to 0 mg/kg ORO, respectively.…”

“…Plant extracts and their secondary metabolites present a strong potential in mitigation with the advantages of efficiency, low risk of host toxicity or residues for the host, in contrast to antibiotics, ionophores or other chemical compounds. Plant essential oils (Paraskevakis, 2018 ), tannins (Hassanat & Benchaar, 2013 ; Salami et al, 2018 ) and saponins (Guyader et al, 2017 ; Liu et al, 2019 ) are the main plant extracts presently studied in ruminant CH 4 mitigation. However, the results of these experiments are diverse even across studies with the same plant extracts, which might be attributed to the plant varieties, additive levels or content of active ingredient.…”

Effect of Rumen Culture Adaptation to Origanum vulgare L. Essential Oil on Rumen Methane and Fermentation

“…The reduction in CH4 with the addition of OEO was consistent with the findings of others (Tekippe et al, 2011;Patra and Yu, 2012;Cobellis et al, 2015;Kolling et al, 2018) and could be attributed to the antimicrobial effects of the OEO on protozoa and methanogenic Archaea as reported by Patra and Yu (2012) and Paraskevakis (2018). Interestingly however, the reduction in CH4 was significant only when OEO was added to the adapted culture suggesting that microbial adaptation and/or modification played a role in OEO effect.…”