Greenhouse gases (GHG) are the prime determinant of global warming phenomena. The main ingredients of GHG are carbon dioxide (CO 2), nitrogen dioxide (NO 2), and methane (CH 4). According to the predictions of the Intergovernmental Panel on Climate Change (IPCC), the surficial temperature is going to increase 1.8-4.0ºC by 2050 [1]. Interestingly, methane is one of the final products, which is produced as a result of the degradation of organic matter (OM), especially carbohydrates in the fore-stomach chamber in ruminants. Furthermore, it is the highest contributor to climate change [2, 3]. The increase of CH 4 is going to run on the production of another serious gas, and the troposphere ozone and human activities are responsible for approximately 70% of global methane [4]. In addition, methane has a more hazardous effect than CO 2 since it binds the earthly warmth 20 times more than CO 2 [5]. This gas is firmly squandering to the feed energy [2]. The livestock sector has an essential role in the current global warming problem, since the gas emission from the ruminants is representing about