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.
Highlights
Enteric methane production from domestic ruminants is one of the largest contributors of greenhouse gas (GHG) emission from agriculture sector
Garlic oil (W250309) from SigmaAldrich Ltd. was examined at four concentrations (0, 1.0 μl, 2.5 μl and 5.0 μl per 30 ml of buffered rumen fluid) to get a concentration of GOL, 0 (Control), 33.33 μl (GOL-1), 83.33 μl (GOL-2) and 166.66 μl (GOL-3) per l of fermentation fluid
The effects on rumen microbial fermentation by addition of essential oils depend on the types of essential oils, their active components and dose of inclusion besides other factors like dietary composition of the animals [22]
Summary
Enteric methane production from domestic ruminants is one of the largest contributors of greenhouse gas (GHG) emission from agriculture sector. Ruminants loss a substantial amount of feed energy [1] due to methane production by the archaea present in rumen. In the diet of ruminants, a significant portion of proteins is solubilized very fast during mastication, resulting release of about 56–65% nitrogen in the rumen fluid, which is responsible for huge losses (25–35%) of nitrogen through absorbed ammonia by rumen wall [2]. Improving feed utilization efficiency in ruminants accelerates animal production and reduces environmental pollution. Supplementation of ionophore antibiotics and other chemicals have been beneficial in achieving these goals. Prohibition of their use by European Unions from 2006 due to development microbial resistance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
