Effect of essential oils and aqueous extracts of plants on in vitro rumen fermentation and methane production

Abstract The objective of this study was to evaluate the effects of eight phytochemicals from four plant species, in two presentations, essential oils (EO) and aqueous extracts (AE) of garlic (GEO, GAE), cinnamon (CEO, CAE), eucalyptus (EEO, EAE) and rosemary (REO, RAE) on rumen fermentation, using the in vitro gas production technique. The experiment was set up as a completely randomized block design in a 2 × 4 factorial arrangement of treatments. All treatments were incubated with 0.5 g of a basal diet (BD; 50% concentrate, 20% alfalfa and 30% corn silage, dry matter basis). Additionally, BD and BD with 30 ppm of sodium monensin (MON) were used as controls. Phytochemicals were evaluated at a single dose of 900 mg/L of inoculum. In vitro dry matter digestibility (IVDMD), maximum volume of gas (Vmax), gas production rate (S) and lag phase (L) were evaluated. Methane (CH4) was determined indirectly, by fixation of CO2present in gas samples with 1M KOH solution, Non-fixed gas was assumed to be CH4. Methane production was correlated with organic matter fermented in the rumen (mL CH4/g OMFR). Data were analyzed using PROC MIXED of SAS ©. The effects of treatments were tested for the following contrasts: EO Vs AE, W Vs EO, W Vs AE. Some essential oils (GEO, CEO, REO) decreased CH4 production (mL CH4/g OMFR) and IVDMD by 20.4% and 17.8% compared to control treatments (BD and MON) (P < 0.05). Aqueous extracts showed a similar response (P < 0.05) to control treatments. In conclusion the use of essential oils negatively affected rumen fermentation and the production of CH4 in P cinnamon essential oil.

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Reducing enteric methane production from buffalo (Bubalus bubalis) by garlic oil supplementation in in vitro rumen fermentation system

SN Applied Sciences ◽

10.1007/s42452-021-04264-6 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Avijit Dey ◽

Shyam Sundar Paul ◽

Puran Chand Lailer ◽

Satbir Singh Dahiya

Keyword(s):

Environmental Pollution ◽

Methane Production ◽

Rumen Fluid ◽

Bubalus Bubalis ◽

Rumen Fermentation ◽

Acetyl Esterase ◽

Garlic Oil ◽

Enteric Methane ◽

In Vitro Rumen Fermentation

AbstractEnteric methane production contributes significantly to the greenhouse gas emission globally. Although, buffaloes are integral part of livestock production in Asian countries, contributing milk, meat and draft power, the contribution of enteric methane to environmental pollution attracts attention. The present study investigated the efficacy of garlic (Allium sativum) oil in reducing enteric methane production from buffaloes (Bubalus bubalis) by in vitro rumen fermentation. Garlic oil (GOL) was tested at four concentrations [0 (Control), 33.33 µl (GOL-1), 83.33 µl (GOL-2) and 166.66 µl (GOL-3) per litre of buffered rumen fluid] in 100-ml graduated glass syringes and incubated at 39℃ for 24 h for in vitro rumen fermentation study. Supplementation of GOL-1 increased (p < 0.05) total gas production in comparison with GOL-3; however, it remained comparable (p > 0.05) with control and GOL-2. Graded doses of garlic oil inclusions reduced (p < 0.001) methane concentration (%) in total gas and total methane production (ml/g DM), irrespective of concentrations. The feed degradability, volatile fatty acids and microbial biomass production (MBP) were not affected (p > 0.05) by GOL-1, but these tended to decrease in GOL-2 with marked reduction (p < 0.01) in GOL-3. The decrease (p < 0.01) in NH3–N concentration in fermentation fluid in the presence of garlic oil, irrespective of concentration, suggests reduced deamination by inhibiting rumen proteolytic bacterial population. The activities of ruminal fibrolytic enzymes (CMCase, xylanase, β-glucosidase, acetyl esterase) were not affected by lower dose (GOL-1) of garlic oil; however, reduction (p < 0.05) of these enzymes activity in rumen liquor was evident at higher doses (GOL-2 and GOL-3) of supplementation. This study shows positive impact of garlic oil supplementation at low dose (33.33 µl/l of rumen fluid) in reducing enteric methane production, thereby, abatement of environmental pollution without affecting feed digestibility.

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