Hundreds of thousands more sheep, pigs and cattle are to be slaughtered in renewed efforts to prevent the further spread of foot-and-mouth disease in Britain.Agriculture Minister Nick Brown told the House Of Commons that in some areas even apparently healthy animals kept within three kilometers of infected farms would all be killed. This means that up to 300,000 more animals are due to be put down.Jim Scudamore, the chief government vet, said the culls would be carried out in areas such as Cumbria, Dumfries, and Galloway, where the infection rate has been highest.But some local farm leaders have reacted angrily to the announcement, saying the new measures would be absolutely devastating.Today 18 further outbreaks of the disease across the country were confirmed by the Ministry of Agriculture, Fisheries and Food in addition to 29 yesterday, bringing the total to 251. The confirmed cases were in County Durham, Devon (four cases), Dumfries & Galloway (three cases), Cumbria (five cases), Powys, Anglesey, Kent, Worcestershire and Oxfordshire.Racing continued, but Bangor and Kelso, both country courses, called off forthcoming fixtures. The British Horseracing Board has informed Britain's 59 courses that if they cannot put on racing now, it assumes they will not race for the duration of the foot and mouth crisis.Michael Webster, the clerk of the course at Bangor, commented: "Everybody is under a lot of pressure and we think this is insensitive. We're not happy at all that they should have sent us this letter under the current circumstances. We're in the middle of an agricultural area and have a dairy farm next door to the track. It's not appropriate for us to race at present."The BHB said its ruling applied to any course calling off after 10 a.m. yesterday. This means that unless the foot and mouth outbreak is over Bangor will not be able to stage on April 21 even if it wants to. Kelso is in a similar position regarding its April 2 fixture after calling off its scheduled fixture for next Friday.Catterick announced this morning that it would race next Wednesday after not going with an earlier fixture.BHB communications manager Alan Delmonte said: "There has been no intention to upset racecourses, but we need to take a longer-term view. The letter was sent out as it has become clear that the foot and mouth outbreak is not going to clear up quickly. It helps everybody if they know which courses can race - we all need a bit more certainty. It's true that some courses have been uncertain whether to race during this time and that this might help them to make up their minds."We have put down the guidelines that will allow racing to continue and a lot of livelihoods are at stake. We are trying to think about the shape of the fixture list. We want to put together a properly structured program in the right geographical areas. We can do this with more certainty if we know which courses will stage fixtures and which ones won't."Stephen Atkin, chief executive of the Racecourse Association, commented: "I have great sympathy for our members in rural areas. Only they know the pressure they are under. The decision taken not to race is not a free decision. It costs them money and won't have been taken lightly. Managing this issue hasn't been easy but we are keen to keep racing going. We support the courses but the BHB has got to put a program together."About 90 countries, including the United States and Australia, have now banned live animal imports and meat and dairy products from the European Union. Countries around the world have also been stepping up measures to contain foot and mouth disease, banning meat and grain imports and increasing checks on travelers from Europe. The U.S. government began disinfection shoes, luggage, and clothing of some travelers arriving from Europe. Japan is taking similar measures.