Evaluation of dietary addition of 2 essential oils from Achillea moschata, or their components (bornyl acetate, camphor, and eucalyptol) on in vitro ruminal fermentation and microbial community composition

Abstract

This study investigated the effects of 2 Achillea moschata essential oils extracted from plants collected in 2 different valleys of the Italian Alps and 3 pure compounds of oils — bornyl acetate (BOR), camphor (CAM), and eucalyptol (EUCA) — on in vitro ruminal fermentation and microbiota. An in vitro batch fermentation experiment (Exp. 1) tested the addition of all of the substances (2 essential oils and 3 compounds) in fermentation bottles (120 mL) at 48 h of incubation, whereas a subsequent in vitro continuous culture experiment (Exp. 2) evaluated the pure compounds added to the fermenters (2 L) for a longer incubation period (9 d). In both experiments, total mixed rations were incubated with the additives, and samples without additives were included as the control (CTR). Each treatment was tested in duplicate and was repeated in 3 and 2 fermentation runs in Exp. 1 and 2, respectively. Gas production (GP) in Exp. 1 was similar for all of the treatments, and short chain volatile fatty acid (SCFA) production was similar in both experiments except for a decrease of SCFA produced ( P = 0.029) due to EUCA addition in Exp. 2. Compared to CTR, BOR and CAM reduced the valerate proportion ( P = 0.04) in Exp. 1, and increased ( P < 0.01) the acetate proportion in Exp. 2. All treatments increased ( P < 0.01) total protozoa counts (+36.7% and +48.4% compared to CTR on average for Exp. 1 and 2, respectively). In Exp. 1, all of the treatments lowered the Bacteroidetes and Firmicutes and increased the Proteobacteria relative abundances ( P < 0.05), whereas in Exp. 2, the EUCA addition increased ( P = 0.012) the Ruminococcus . In Exp. 1, methane (CH 4 ) as a proportion of the GP was lowered ( P = 0.004) by the addition of CAM and EUCA compared to CTR, whereas in Exp. 2, EUCA reduced the amount of stoichiometrically calculated CH 4 compared to CTR. Overall, essential oils extracted from A. moschata and the pure compounds did not depress in vitro rumen fermentation, except for EUCA in Exp. 2. In both experiments, an increase of the protozoal population occurred for all the additives.

Characteristics of Ruminal Fatty Acids Using In Vitro Culture System by Addition of Galangal (Alpinia galangal) Essential oil

“…Furthermore, [32] also reported that rumen bacteria would degrade the monoterpenes compounds during six hours of incubation. In this research, dosage of galangal EO is equal to 24% of cineole and similar results with [31] that cineole and A. moschata EO have different results on the rumen fermentation.…”

“…Cineole, the main component of galangal EO, also has almost the same activity as phenol in the presence of an ether group that is reactive in binding lipase and reduce the bacterial activity. According to [31] the effects of Achillea moschata essential oil and three main components were consisting of d bornyl acetate (BOR), camphor (CAM), and eucalyptol (EUCA) have different effects on rumen microbes. Furthermore, [32] also reported that rumen bacteria would degrade the monoterpenes compounds during six hours of incubation.…”

Effect of galangal essential oils on rumen microbial population and biodiversity on in vitro rumen fermentation

“…Furthermore, with its hydrophobic nature, cineole more easily crosses the plasma membrane of the protozoa and causes mitochondrial swelling. This study is almost the same as Colombini et al (2021) that adding Achillea moschata essential oil with cineole as the main compounds caused a decrease in the genus Euryarchaeota by 35.26%.…”

In vitro effects of different levels of quebracho and chestnut tannins on rumen methane production, fermentation parameters, and microbiota

“…For VFA determination, 1 ml of 25% meta-phosphoric acid was added to 5 ml of supernatant as described by Colombini et al ( 27 ). After 30 min, the mixture was centrifuged again at 3,500 × g for 10 min.…”