Bovine TB is a major problem across certain parts of the UK. The disease can spread from cow to cow, but may also affect and be spread by badgers, deer, cats and a number of other mammals. The current government 'solution' to this problem is to test the cattle and cull any that react to the tuberculin skin test. If a herd gets a high proportion of animals with TB, then DEFRA vets might have the whole herd slaughtered - the farmer receives compensation for the culled animals, but there is nothing that can be done to cover the loss of a prized herd. A herd has to stay under quarantine until the whole herd has tested clear - in serious outbreaks it can take years.
Below you can see pictures of the vet and assistants taking TB tests (once a year on this farm) and also taking blood for Brucellosis testing (which happens once every two years)
|Collecting the cattle prior to testing||Running them through the race, into the crush||Making the cow secure|
|Preparing a cow for the test||Checking skin thickness with calipers||Taking the blood sample|
|Releasing the cattle||Calves over 6 weeks are also tested||Recording initial values|
Steve, the vet is taking the TB tests while his assistants take the blood sample and record initial readings against a record of each animal.
The TB test is done by shaving a part of the neck and pricking the skin in two places, first with an antigen from bovine TB and then one from avian TB. After 3 days the neck is examined and checked for large bumps. Just like people, some animals are more sensitive than others and produce a small response to the test. A bump for the avian TB and none for bovine TB is okay. A small bump at both sites is okay so long as the avian bump is bigger than the bovine one. A middle-sized bovine lump gives an inconclusive reaction and the animal is tested again in a few weeks - with luck it will go clear at the second test. The TB test works well on a herd basis and is good at finding if TB is present on a farm. Unfortunately is isn't so good at giving an accurate individual result as there can be both false positives and false negatives. However, it is the only test available at present and at Fowlescombe on the rare occasion when we bring in new stock we test the animals before buying them.
This farm tested all clear this year. Last year it had one cow that had to be re-tested as it was 'inconclusive' but it was OK on a retest.
Pictures taken byRichard Barker