Factors affecting mitigation of methane emission from ruminants: Microbiology and biotechnology strategies

Climate change is a subject of global environmental concern. Increased anthropogenic Greenhouse Gas (GHG) emissions have increased the global temperature the last 100 to 200 years. Carbon dioxide and methane are the main greenhouse gases related to animal nutrition and methane has greater global warming potential than carbon dioxide. Among greenhouse gases, methane is considered a potent greenhouse gas with 21 times more global warming potential than carbon dioxide. Worldwide, ruminant livestock produce about 80 million metric tons of methane each year, accounting for about 28% of global emissions from human related activities. Therefore it is impelling animal scientists to finding solutions to mitigate methane emission from ruminants. It seems that solutions can be discussed in four topics including: nutrition (feeding), biotechnology, microbiology and management strategies. We have already published the first and second review articles on feeding strategies and management strategies. In the current review, Microbiology and biotechnology such as emphasizing on animal breeding, genetic merit, bovine somatotropin (BST), unproductive animals, vaccination, immunisation and biological control (bacteriophage, acetogenesis reductive), chemical defaunation that can be leads to decreasing methane production from ruminant animal production are discussed.