TB in cows is due to factory farming and diet. Same with humans
http://www.whale.to/vaccine/bcg1.html
vaccine useless
Badgers and TB (letter)
Sir: Again, outbreaks of bovine TB are, understandably, causing
concern to farmers. ("Badgers get blame for epidemic", 1 December)
Human TB has been largely conquered in Britain by better housing and
nutrition. The Richards report (1972) by the Ministry of Agriculture
on the outbreak of bovine TB in West Cornwall suggested that bad
husbandry and management of cattle herds was a major cause.
Then the bacillus was found in a badger carcass and the efforts of
the ministry and the National Farmers Union were concentrated on the
culling of ba gers and other possible causes were largely ignored.
Dairy cattle are no longer fed on herb-rich grassland but on grass
monocultures, and their diet is supplemented by manufactured
protein-rich foods to boost milk yield. They are confined for long
periods, in close proximity, in milking sheds and in winter housing.
This must lead to the spread of the disease between individuals.
Selection of breeding stock takes account, almost exclusively, of
milk yield. Natural immunity to disease is disregarded.
Twenty-five years of culling programmes has cost many millions of
pounds and destroyed more than 25,000 badgers, and the disease is
still rife.
It is to be hoped that the Krebs report, now with the minister, will
soon be released and that, for the sake of farmers and the dairy
industry, it will deal with the scientific evidence rather than
political considerations. J K WILLIAMS Camborne Cornwall