Image caption Bovine TB has led to the slaughter of tens of thousands of cows

Ministers have set out their long-term plans for fighting TB in cattle - aiming for England to become TB-free within 25 years.

Cases of bovine TB have risen in parts of England and Wales over the past two decades.

Environment secretary Owen Patterson called the issue "the most pressing animal health problem in the UK".

Plans include a controversial cull of badgers, due to start this year in two areas of South West England.

But the draft strategy published on Thursday said that "further research into alternative population control methods (e.g. sett-based culling methods and non-lethal methods) is also under consideration".

That could include injecting badger setts, or dens, with gases or gas-laden foam that displace oxygen, and "proof-of-principle" experiments are being carried out into the use of contraceptives.

Launching the strategy, Mr Paterson said: "Bovine TB is the most pressing animal health problem in the UK. It threatens our cattle farmers' livelihoods and our farming industry as well as the health of wildlife and livestock.

Bovine TB Bovine TB is an infectious disease that mainly affects cattle

It also infects other animals, including the badger

Cattle with bovine TB are most often identified through testing using the tuberculin skin test before they develop obvious signs of the disease

This is because the disease usually progresses slowly and it can take some time for clinical signs to appear

When TB breaks out in a herd, affected cows are destroyed, and movement restrictions are placed on a farm

The English and Welsh governments estimate they have spent £500m in the last decade on testing, compensation and research

"We must all work together to become TB-free within 25 years."

The government's policy to control bovine TB has been a matter of much debate, because of its implications for the farming industry and because one option is to cull badgers.

Badger culling has been authorised at two pilot sites in West Somerset and in and around West Gloucestershire.

Under the proposals, about 5,000 badgers will be culled by free shooting before the end of the year.

Ministers say the action is needed to help tackle the cattle disease, which has been steadily rising since the 1980s.

Campaigners against the cull say it will have no impact on bovine TB, and could lead to local populations of badgers being wiped out.

The strategy sets out action in areas including:

Disease surveillance

Pre- and post-movement cattle testing

Removal of cattle exposed to bovine TB

Tracing the potential source of infection

Wildlife controls including culling and vaccination trials.

It also focuses on the role of badger and cattle vaccines, and diagnostic tests that could one day offer new ways of tackling the disease.

Vaccination of badgers is already underway in Wales as an alternative to culling. A similar vaccine for cattle exists, but its use is prohibited by EU regulations.

Scotland has been officially TB free since 2009.

Cycle of infection

Farming Minister David Heath said there was no single answer to the problem of TB in England.

Analysis Twenty five years to wipe out TB in cattle seems like a long-time, but in many ways it's an ambitious target. As one scientist put it, there are no quick fixes. Experience around the world has shown that once TB has become established in populations of domestic and wild animals, measures to control it are both costly and difficult. Australia is one of the few countries to have successfully eradicated TB in cattle and wild water buffalo, a process which took 27 years. The government's long term strategy for the control of bovine TB in England contains no startling new revelations, but pulls together various strands and policies, involving the government, the farming industry, vets and scientists. It also focuses on the idea of dividing England into three areas - low risk, high risk and the edge between the two areas - and tackling each area with different interventions. A key hurdle in the coming months is the reaction of farmers, who will inevitably bear some of the costs of the new strategy.

He told the BBC: "We know that we have a badger population which has TB and is infecting both other badgers and cattle in the same way that cattle are infecting badgers. So we've got this cycle there - we need to break that cycle.

"Culling is part of that process because that deals with the infected badger and no other measure I'm afraid deals with badgers which are already infected. You can't vaccinate a badger and remove the infection. But we also need to protect the healthy badgers."

He said research was underway to better identify which badgers are infected with TB, and which are not. Experts are also developing an oral badger vaccine against TB, which the government hopes to deploy in 2019.

The farming minister added: "We shall be using those vaccines - as we are already - but increasingly so particularly on the edge areas of infection so that we're protecting clean badger populations from infection and therefore stopping the spread of the disease.

"I think if we put all those things together then we can achieve our objective which is healthy cattle and healthy badgers living side by side."

Divisions of opinion

On Thursday, scientists released a document setting out the scientific evidence for and against culling badgers, following concern that data on badger culling is being misrepresented by both sides of the debate.

Charles Godfray of the Oxford Martin School at the University of Oxford, co-author of the Natural Science Evidence Base for Control of Bovine TB study, said: "Agreeing on what the science says is important because it means everyone can discuss the topic based on a shared evidence base.

"The assumptions upon which policy is based, and the expectations about its results, must also be consistent with what the science tells us."

Professor Robbie McDonald, chair in natural environment, environment and sustainability Institute at the University of Exeter added: "I welcome the government's recognition that 25 years of hard work lies ahead. There are no quick fixes here and it would take 25 years to get to TB free status, even if everyone agreed what to do.

"There are deep-seated conflicts and divisions of opinion over what to do about badgers and effective intervention in the wildlife component of the TB problem needs support from government, industry and the wider public."