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

Abstract

Enteric 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.

Potential of graded doses of neem (Azadirachta indica) seed oil on ruminal fermentation characteristics, degradability, and methane formation in vitro

“…Differences observed with ruminal fermentation and feed degradability may possibly explained by differences in dose, dietary composition, and controlled in vitro conditions used. In addition, the potential effect of vegetable oils supplemented to the diet on abatement of CH4 coincided with previous in vivo (Mao et al, 2010;Bayat et al, 2018;Lima et al, 2019) and in vitro (Dey et al, 2021) research findings. Diet supplemented with NSO affected net GP, feed degradability, and ruminal fermentation in a dose-dependent manner.…”

Effects of Processing Methods and Inclusion Levels of Dried Garlic on In Vitro Fermentation and Methane Production in a Corn Silage-Based Substrate

“…In this experiment, acetate and propionate proportions showed a quadratic and linear response when increasing garlic inclusion, respectively ( Table 2 ). Similar to the concentration of NH 3 -N, fermentation may be affected differently according to the garlic inclusion level [ 30 ]. Additionally, the greater concentration of NH 3 -N at 2.5% of garlic inclusion could explain the greater proportion of acetate because acetogenic bacteria mainly utilize NH 3 -N as a source of nitrogen [ 29 ].…”

Potential use of garlic products in ruminant feeding: A review

“…(2021) Garlic oil 2 mL/d per sheep 122 d sheep the pregnant vivo = ↓ – – – – – – = Mahmoud and Salah (2017) Garlic oil 0.4, 0.8 and 1.2 63 d lambs 2.5–3 mo vivo ↑ ↓ ↓ ↓ ↓ ↓ ↓ – ↓ Canbolat et al. (2021) Garlic oil 1.0, 2.5, and 5.0 μL per 30 mL of buffered rumen fluid after 24 h of incubation Murrah buffalo steers 2.5 yr vitro – ↓ ↓ (2.5, 5.0) ↑ (5.0) ↓ (1.0, 2.5) ↑ (1.0) – ↓ – Dey et al. (2021) Garlic oil 3, 30, 300 and 3000 mg/L of rumen fluid 8 d – – vitro ↑ (300, 3000) ↑ (300) ↓ (30, 300, 3000) ↑ (30, 300, 3000) – ↑ (30, 300, 3000) – ↓ ↓ (300, 3000) Busquet et al.…”

“…Garlic powder, oil and allicin are able to reduce the methane emissions of ruminants ( Dey et al., 2021 ; Ma et al., 2016 ; Zafarian and Manafi, 2013 ). Zafarian and Manafi (2013) demonstrated that the addition of 20 g/kg of garlic powder (DM basis) into the diet for 120 d can produce a 31% reduction in methane emissions from lactating Murrah buffaloes.…”