Culling to the point of extermination by repeated gassing, as at Steeple Leaze and Thornbury, worked insofar as there has been no further TB in cattle or recolonising badgers there. Furthermore, under the "clean ring" strategy of 1982-5, the number of TB breakdowns in cattle fell to an all- time low of 53 in 1985.
After that year, the less intensive "interim" strategy was used, a practice in which badgers were trapped only on the land grazed by the infected cattle. The proportion of infected badgers thus caught probably never approached 100 per cent and from MAFF data one can estimate that it was usually less than 50 per cent.
Not a very effective strategy therefore, but it may have had some effect since the biggest recent increases in tuberculous infection have been in areas where no badgers had ever been culled. These areas - the Exe Valley, Hereford and Worcester, central Wiltshire, Monmouthshire and Shropshire - include those where the national badger surveys have shown the biggest increases in badger populations. The farmers' call for some control over badger numbers seems justified.