Swine fever is a highly infectious pig disease but not dangerous to humans. In the past it has required large slaughtering programmes to stamp it out and many countries also ban imports of pork from places with the disease.

The wild pig population has grown rapidly in Rhineland-Pfalz in recent years and some are known to suffer from swine fever. The disease can be spread by wild pig excrement sticking to car tyres or to shoes and then being brought into farms.

"We need a long term answer to this problem and we are optimistic the programme to immunize the wild animals will start to reduce the number of cases and in the long term stamp the disease out," said a state environment spokesman.

"We have also asked hunters to spread the bait for us as they know they know the best places to find the wild animals."

In addition, "we have also said hunters may increase the number of wild pigs they shoot and we are also considering an extension to the hunting season," the spokesman added.