Impact of Supplementing Essential Oils on Reduction of Enteric Methane Emission in Indigenous Dairy Cattle

Abstract

Background: Globally enteric methane emission is the largest contributor of anthropogenic global warming and methane is the second largest driver of global radiative forcing after carbon dioxide. The present study was conducted to evaluate the effect of supplementing essential oils (EOs) in combination of garlic oil and peppermint oil on enteric methane emission in indigenous dairy cattle. Methods: Eight indigenous dairy cattle were divided into two groups supplemented with essential oils in combination of garlic oil and peppermint oil (2.4 mL/animal) as treatment group and without supplementation with paddy straw and concentrate feed (60:40) based diet. A digestibility trial was conducted during the last six days of 30 days feeding trial to evaluate the effect of essential oils in combination on nutrients digestibility. The total methane emission was estimated by sulfur hexa fluoride tracer gas technique (SF6). Result: No significant difference in DMI, TDN and DCP intake could be noted with supplementation of essential oils in indigenous dairy cattle. However, cows fed with combination of garlic oil (GO) and peppermint oil (PO) significantly (P<0.05) reduced the methane emission by 10.60% in comparison to control group. Hence, the feasibility of feeding essential oils can be considered at farm level as a methane mitigation strategy.