Hi folks,
There's been a long standing belief, certainly in the UK, that bovine TB is spread to cattle by badgers, leading to massive badger culls to prevent this.
However, this has been challenged.
I saw this documentary in December, and thought yous might find it interesting / useful. Here's a brief synopsis.
Brian May (guitar, Queen) has for a long time been a campaigner for the protection of badgers. As you might guess, some farmers whose families have been farming for generations were not keen on being taught their craft by someone whose best known credentials are in music (as epic as those might be).
May was in contact, as a campaigner, with other farmers conducting research on the bovine TB / badger connection.
The upshot of the research was this:
Farmers have for a long time been convinced that badgers were the source of TB, as herds have become contaminated when the only incoming bulls had previously been tested for TB, and declared clear.
However, those tests have been shown to be inadequate. The programme gave an example of a bull that had passed the standard test many times over, but after being slaughtered, was found to be
riddled with TB.
Therefore, farmers who've been convinced that the only possible vector for TB to their herd was from wildlife, specifically badgers - that theory is shown to be uncertain.
What was found to be the primary vector for the disease was manure from an infected cow, although standard testing practice had not been to test manure.
In standard farming practice, cows' manure is spread over fields that are grazed by the same herd. If one cow / bull was brought into the herd with TB, that would spread via their manure to the other cows.
Once this was discovered, the farm altered their practices, e.g. watering troughs were adapted to make it impossible for cows to back into them, to prevent them from polluting the water with manure.
At the end of the documentary, May presented these findings to an audience of farmers. Aware of the risk of it looking like a guitarist lecturing farmers on farming, his presentation to the farmers was handled with all due respect, just laying out these discoveries and innovations, and telling them it was not their fault, they had simply been lied to about the source of TB outbreaks.
Very interesting programme. It didn't prove that badgers had no involvement in the spread of TB, but it did show that the primary vectors were from within the cattle herds themselves, and badgers may have been the victims of TB from cattle, more than the other way around.
As someone interested in health history, I found this all analogous to the plagues of the 1700s-1800s in the West. With the industrial revolution, people rushed to the cities, which had inadequate infrastructure to support them. Among other factors, hygiene was unimaginably bad, with highly polluted sources of drinking water, and these were the primary drivers of epidemics. Primary credit for improvements in public health in this time belongs to sanitary engineers.
So there's a point of continuity with the bovine TB story. Clean water, and clean food are key to health, even in animals.
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