Plant Extracts Affect In Vitro Rumen Microbial Fermentation

Abstract

Different doses of 12 plant extracts and 6 secondary plant metabolites were incubated for 24 h in diluted ruminal fluid with a 50:50 forage:concentrate diet. Treatments were: control (no additive), plant extracts (anise oil, cade oil, capsicum oil, cinnamon oil, clove bud oil, dill oil, fenugreek, garlic oil, ginger oil, oregano oil, tea tree oil, and yucca), and secondary plant metabolites (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol). Each treatment was supplied at 3, 30, 300, and 3,000 mg/L of culture fluid. At 3,000 mg/L, most treatments decreased total volatile fatty acid concentration, but cade oil, capsicum oil, dill oil, fenugreek, ginger oil, and yucca had no effect. Different doses of anethol, anise oil, carvone, and tea tree oil decreased the proportion of acetate and propionate, which suggests that these compounds may not be nutritionally beneficial to dairy cattle. Garlic oil (300 and 3,000 mg/L) and benzyl salicylate (300 and 3,000 mg/L) reduced acetate and increased propionate and butyrate proportions, suggesting that methane production was inhibited. At 3,000 mg/L, capsicum oil, carvacrol, carvone, cinnamaldehyde, cinnamon oil, clove bud oil, eugenol, fenugreek, and oregano oil resulted in a 30 to 50% reduction in ammonia N concentration. Careful selection and combination of these extracts may allow the manipulation of rumen microbial fermentation.

Effects of essential oils on proteolytic, deaminative and methanogenic activities of mixed ruminal bacteria

“…However, in a subsequent study by the same group (Busquet et al 2006), no changes in NH 3 concentration were observed when garlic oil was used at the same concentrations (3, 30, 300, and 3000 mg L…”

“…However, the increased pH was not accompanied by a significant decrease in total VFA concentrations although the later were numerically lower for treatments than for the control treatment. Results of the effects of EO and their compounds on total VFA concentration have been inconsistent depending on the type and the dosage rate of EO or EOC used (Busquet et al 2006). Nevertheless, in most studies, supplementation with EO or their compounds either decreased or had no effects on total VFA concentration.…”

“…Nevertheless, in most studies, supplementation with EO or their compounds either decreased or had no effects on total VFA concentration. For instance, Busquet et al (2006) examined the effects of various EO (anise, cade, capsicum, cinnamon, clove bud, dill, garlic, ginger, oregano, and tea tree) and their compounds (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol) on ruminal fermentation using 24-h in vitro batch culture when each additive was supplied at 3, 30, 300, and 3000 mg L (1 . At the lowest concentrations (i.e., 3 and 30 mg L…”

The effects of lemon verbena (<i>Lippia citriodora</i>) verbascoside on the productive performance, plasma oxidative status, and some blood metabolites in suckling lambs

“…In an experiment carried out on fattening lambs that consumed mixed feed with a blend of essential oil compounds having antioxidant activity, Ozdogan et al (2011) showed a slight improvement in BW and ADG, which could likely be due to the modification of rumen volatile fatty acid production by increasing the acetate-to-propionate ratio, inhibiting deamination, and the direct inhibition of methane production (Busquet et al, 2006;Castillejos et al, 2007). Corino et al (2007b) conducted a similar study on piglets in post-weaning; piglets were fed with a concentrate that was supplemented with two levels of VB, and the authors found considerable growth improvement in the subjects that were fed the highest level of VB.…”

Effect of oregano oil onin vitrogas production, digestibility and metabolisable energy of some feedstuffs

“…Results of these studies showed variable effects of essential oils and their derivatives on rumen bacteria and ruminal fermentation (Busquet et al 2006;Castillejos et al 2006). Discrepancies among studies were attributed to difference in type and doses of essential oils (Busquet et al 2006) and differences in technique used in these experiments .…”