In prehistoric times, humans hunted aurochs and later domesticated them. Since then, numerous breeds of cattle have been bred specifically for the quality or quantity of their meat. Today, beef is the third most widely consumed meat in the world, after pork and poultry. As of 2018, the United States, Brazil, and China were the largest producers of beef. In the United States, beef production has come to rely heavily on factory farms. The prevalence of manure in these farms has been linked to contamination of beef with E. coli, leading to large recalls, as well as increased antibiotic usage. The now-restricted use of meat and bone meal feed was historically responsible for outbreaks of bovine spongiform encephalopathy ("mad cow disease").
Beef can be prepared in various ways; cuts are often used for steak, which can be cooked to varying degrees of doneness, while trimmings are often ground or minced, as found in most hamburgers. Beef contains protein, iron, and vitamin B12. Along with other kinds of red meat, high consumption is associated with an increased risk of colorectal cancer and coronary heart disease, especially when processed. Beef has a high environmental impact, with the highest per gram greenhouse gas emissions of any agricultural product. Requiring high land use, it is the primary driver of deforestation in the Amazon rainforest, with approximately 80% of deforested land used for beef production.