All farm animals should be tested for a form of the superbug MRSA, an organic group has urged the government.
Thirty nine per cent of pigs were found to have the bug
The Soil Association says the bug is widespread in the Netherlands, Belgium and Germany, from where some of the meat eaten in the UK is imported.
In the Netherlands, 39% of pigs tested positive for the bug which can be passed to humans.
And 13% of calves also tested positive for the bug, which is different to the strain found in hospitals.
The studies found that 50% of farmers were also positive, some of whom have been resistant to antibiotics.
The Soil Association blamed the use of antibiotics in farming for the problem.
No MRSA has been found in British farm animals but poultry meat and pork is imported from infected countries.
The Food Standards Agency says people will not catch the bug from meat if it is prepared hygienically and cooked properly.