Milk Cow Silhouette Beef Cattle Moo Bull Steer Key Ring

They are the most widespread species of the genus Bos, most commonly classified as Bos primigenius. Cattle are raised as livestock for meat (beef and veal), as dairy animals for milk and other dairy products, and as draught animals (pulling carts, ploughs and the like). Other products include leather and dung for manure or fuel. In some countries, such as India, cattle are sacred. It is estimated that there are 1.3 billion cattle in the world today. In 2009, cattle became the first livestock animal to have its genome mapped.\ A 400-page United Nations report from the Food and Agriculture Organisation (FAO) states that cattle farming is "responsible for 18% of greenhouse gases."[38] The production of cattle to feed and clothe humans stresses ecosystems around the world,[37] and is assessed to be one of the top three environmental problems in the world on a local to global scale. The report, entitled Livestock's Long Shadow, also surveys the environmental damage from sheep, chickens, pigs and goats. But in almost every case, the world's 1.5 billion cattle are cited as the greatest adverse impact with respect to climate change as well as species extinction. The report concludes that, unless changes are made, the massive damage reckoned to be due to livestock may more than double by 2050, as demand for meat increases. One of the cited changes suggests that intensification of the livestock industry may be suggested, since intensification leads to less land for a given level of production. Some microbes respire in the cattle gut by an anaerobic process known as methanogenesis (producing the gas methane). Cattle emit a large volume of methane, 95% of it through eructation or burping, not flatulence.[40] As the carbon in the methane comes from the digestion of vegetation produced by photosynthesis, its release into the air by this process would normally be considered harmless, because there is no net increase in carbon in the atmosphere — it's removed as carbon dioxide from the air by photosynthesis and returned to it as methane. Methane is a more potent greenhouse gas than carbon dioxide, having a warming effect 23 to 50 times greater,[41][42] and according to Takahashi and Young "even a small increase in methane concentration in the atmosphere exerts a potentially significant contribution to global warming".[42] Further analysis of the methane gas produced by livestock as a contributor to the increase in greenhouse gases is provided by Weart.[43] Research is underway on methods of reducing this source of methane, by the use of dietary supplements, or treatments to reduce the proportion of methanogenetic microbes, perhaps by vaccination.