Changes to rules governing the movement of cattle between linked holdings will cause havoc and could put producers and vets in danger of injury, according to the NFU.
Plans to tighten the operation of Sole Occupancy Authorities are impractical and unnecessary, increasing the burden of red tape without reducing the risk of TB, the union said during a seminar at the Devon County show on 17 May.
Alex Stevens, food and farming adviser at NFU South West, said: "We were assured by DEFRA that these changes would only be put into place following industry consultation and if there was a suitable alternative system - neither of which have happened."
The changes mean farmers will have to test cattle before moving them within Sole Occupancy Authorities that had holdings in high and low-risk TB areas.
From 1 July, DEFRA will refuse to grant any new SOAs.
New Cattle Tracing System links between holdings in high and low-TB risk areas would also be refused. Existing links between high and low-risk areas would be removed on a phased basis.
"This is going to cause a lot of headaches in the South West," said Mr Stevens. "Many producers take grass keep in the summer, which do not have appropriate facilities for TB testing. Having to test animals without proper facilities - often to move them to a new field a mile down the road - will lead to significant practical and safety issues.
"It will also make it very hard for new entrants to get on the farming ladder if they are restricted in taking bits of land around the area," he added. "That is how a lot of people get started - they need to be able to move their cattle to graze. This is purely extra red tape that will make it harder for people to run their businesses."
The NFU was urging DEFRA to reconsider the rules, to allow farmers to move cattle within high-risk areas with the same TB testing intervals without needing a pre-movement test. Only those moving from high to low-risk areas should be affected.
"The change appears to be out of line with the rest of the announcements, which aim to limit the untested movements of stock between high and low-risk areas, not limit the untested movements of all stock on a farm," said chief livestock adviser Peter Garbutt. "We are requesting that DEFRA issue a clarification that the restriction on new or enlarged SOAs would just be for blocks of land between high and low-risk areas. Until the matter is resolved, we will be advising farmers to register all SOAs they believe are necessary before 1 July."
The movement rule changes were announced by DEFRA on 2 May by DEFRA farm minister, Jim Paice.
At the time, Mr Paice said: "We need to stop the spread of bovine TB, that last year led to the slaughter of 26,000 cattle and could cost the taxpayer £1bn pounds over the next 10 years unless action is taken."
"Farmers have shown their commitment to tackle this devastating disease, which is taking a terrible toll on their communities and businesses. These strengthened measures, alongside work to pilot badger culling, and the development of badger and cattle vaccines, aim to help control the disease and eventually eradicate it."
A DEFRA spokesperson said: "Controlling animal disease, including bovine TB, is essential to protect England’s beef and dairy industry, and we need to tighten cattle movement controls within Sole Occupancy Authorities for effective TB control.
"We shared details of the changes due to come into effect on 1 July with the NFU and will continue to discuss their practical implications with them and others."