Mycobacterium bovis is a slow-growing (16- to 20-hour generation time) aerobic bacterium and the causative agent of tuberculosis in cattle (known as bovine TB).

The cell wall contains as high as 60% lipid, giving the mycobacteria their hydrophobic characteristics, slow growth, and resistance to desiccation, disinfectants, acids, and antibodies.

[citation needed] Initially (after 3–4 weeks), its minute, dull flakes, begin to thicken to form dry, irregular masses standing high above the culture medium surface.

Eventually, confluent growth is seen over the whole culture surface, forming a rough, waxy blanket, becoming thick and wrinkled and reaching up the sides of the container.

Unlike M. tuberculosis, M. bovis lacks pyruvate kinase activity, due to pykA containing a point mutation that affects binding of Mg2+ cofactor.

[citation needed] During the first half of the 20th century, M. bovis is estimated to have been responsible for more losses among farm animals than all other infectious diseases combined.

[4] M. bovis is usually transmitted to humans by consuming raw milk from infected cows, although it can also spread via aerosol droplets.

[5] Bovine tuberculosis is a chronic infectious disease that affects a broad range of mammalian hosts, including humans, cattle, deer, llamas, pigs, domestic cats, wild carnivores (foxes, coyotes) and omnivores (common brushtail possum, mustelids and rodents); it rarely affects equids or sheep.

For example, at Hohotaka, in New Zealand's central North Island, control work from 1988 to 1994 achieved a sustained mean reduction of 87.5% in the density of TB‐infected possums.

[17] According to DEFRA and the Health Protection Agency, the risk to people contracting TB from cattle in Great Britain would be low.

[citation needed] Badgers (Meles meles) were first identified as carriers of M. bovis in 1971, but the report of an independent review committee in 1997 (the Krebs Report) concluded: "strong circumstantial evidence [exists] to suggest that badgers represent a significant source of M. bovis infection in cattle... [h]owever, the causal link... has not been proven".

[18] In essence, the contribution of badgers 'to the TB problem in British cattle' was at this point a hypothesis that needed to be tested, according to the report.

Second, weaknesses in cattle-testing regimens mean that cattle themselves contribute significantly to the persistence and spread of disease in all areas where TB occurs, and in some parts of Britain are likely to be the main source of infection.

Scientific findings indicate that the rising incidence of disease can be reversed, and geographical spread contained, by the rigid application of cattle-based control measures alone."

[23][24] One of the reasons that the Department for Environment, Food, and Rural Affairs requires infected or suspected cattle to be culled is to meet EU regulations for the export of meat and dairy products to other member states.

Meat and dairy products can still be sold in the UK into the human food chain, providing the relevant carcass inspections and milk pasteurisation have been applied.

[27] In a 2010 opinion piece in Trends in Microbiology, Paul and David Torgerson argued that bovine tuberculosis is a negligible public health problem in the UK, providing milk is pasteurized.

Therefore, the bovine tuberculosis control programme in the UK in its present form is a misallocation of resources and provides no benefit to society.

Milk pasteurisation was the single public health intervention that prevented the transmission of bovine TB to humans, and no justification for the present test and cull policy in the UK is seen.

The paper was authored by Graham Godwin-Pearson with a foreword by singer Brian May and contributions by leading tuberculosis scientists, including Lord Krebs.

[39] Vermont was exceptional, for across the country many farmers strenuously resisted bovine tuberculosis eradication as an expensive violation of their libertarian right to farm.

M. bovis is endemic in white-tailed deer (Odocoileus virginianus) in the northeastern portion of Michigan and northern Minnesota, and sporadically imported from Mexico.

[41] The fact that white-tailed deer are a maintenance host for M. bovis remains a significant barrier to the US nationwide eradication of the disease in livestock.

Australia is officially disease-free since the successful BTEC program, but residual infections might exist in feral water buffalo in isolated parts of the Northern Territory.

In Canada, affected wild elk and white-tailed deer are found in and around Riding Mountain National Park in Manitoba.

[53] The 2017 Roadmap identified ten priority areas for addressing zoonotic tuberculosis, which includes collecting more accurate data, improving diagnostics, closing research gaps, improving food safety, reducing M. bovis in animal populations, identifying risk factors for transmission, increasing awareness, developing policies, implementing interventions, and increasing investments.