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Posted: Sun May 10, 2009 12:11 pm
by Saffy
I am aware that TB can be passed from animal to animal and farm to farm through cow muck and slurry and potentially by streams and watercourses that have been polluted with muck and slurry. Also that badgers can pass it to cattle through the cattle drinking from a stream.
Does anyone here know how long TB lives in cow muck? Is it always there? Or is it maybe only weeks or months after it has been passed by the animal? What about in a watery slurry or after it is on a field?
May sound an odd question but our tenant has polluted one of our paddocks with muck from a yard he rents and we have fenced the area off for a few months with an electric fence. We are wondering when we can allow our animals to graze it again. To make matters appear worse it has gone onto an already damp patch!
Does anyone have any ideas or know where to find the answer?
Stephanie
Edited By Saffy on 1241953883
Posted: Sun May 10, 2009 3:07 pm
by Broomcroft
I met a specialist TB vet last year who lives, eats and breathes TB (not literally!). He said in the midlands, 85% of TB comes from badgers, 10% from cattle to cattle, and 5% from a variety of other sources. He said it is getting to the point in some areas where every single badger is infected.
Edited By Broomcroft on 1241964474
Posted: Sun May 10, 2009 3:31 pm
by redhill
Hello Stephanie,
hope this helps, best wishes Sue
The spreading of slurry on grazed land.
A Veterinary Risk Assessment has been carried out into the potential dangers of spreading slurry on grazed land, and concluded that:
Slurry has the potential to spread bovine TB via two routes: ingestion (via the pharynx and gut) and respiratory (via the lungs); however, in order to do this, the slurry must first contain viable M. bovis organisms in sufficient quantity. This is
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highly unlikely under the conditions existing in the UK as a result of current cattle controls.
For slurry to be a source of infection for bovine tuberculosis a number of important events must take place in sequence: At least one bovine in the herd must be (1) infected AND (2) infectious AND (3) shedding bacteria in faces or urine.
The infected slurry must come contain (4) an infectious dose of (5) viable M. bovis AND these must (6) come into effective contact with at least one (7) susceptible animal via the respiratory system or the gut.
In order to do this, it must (8) survive storage and the (9) environment, either on or in the ground, or in the air as an aerosol, for long enough to contact a susceptible animal.
Within the recipient animal, the organism must (10) reach a suitable site AND (11) survive to replicate.
In parallel with the above there is an important dilution effect of air, uninfected soil and uninfected slurry that greatly reduces the likelihood of infection. It is also important to note that the oral dose required for infection swallowed via the gut is considerably greater than that required for infection inhaled via the respiratory system.
Given the difficulty in determining the role of slurry in disease spread, advice on this was not included in the leaflets because it was not certain that it could be expected to have any effect.
Posted: Sun May 10, 2009 3:33 pm
by redhill
PS.this is from DEFRAS website, sue
Posted: Sun May 10, 2009 7:15 pm
by Saffy
Thanks Sue
Our tenant does have quite an on going TB problem - hence the concern but thanks for putting my mind at rest.
We will probably take the fence up in a week or so when we are a little short of grass as we are shutting some up for hay from now on.
Stephanie :D