Carmarthenshire-based vet Paul Rodgers has been working with the Welsh Government and making biosecurity visits to farms in bovine TB areas. He offers some advice on taking precautions against the disease.
Farming in an area where bovine TB (bTB) is endemic in the wildlife population and TB tests frequently identify TB-infected cattle can be stressful.
However, at farm level, there are still a number of practical precautions which can be taken to minimise the risk of your cattle becoming infected, says Carmarthenshire-based vet Paul Rodgers.
Assessing the risks The bTB status of your area and individual farm dictate the main risk factors for you:
“Ideally, cattle should not be moved in from endemic areas or from other farms which have introduced animals from high risk areas. If you need to, a strict buying-in policy is needed. Minimising contact with wildlife is still important to reduce chances of introducing TB into an uninfected badger population.”
Biosecurity measures In TB areas, or where badgers are present, there is a chance of TB-infected badgers coming into contact with grazing cows.
Cattle can become infected from other cattle through co-grazing, shared housing, at shows, returns from market and grazing/housing away from home premises with direct (nose-to-nose) or indirect (shared water) contact with other herds, says Mr Rodgers.
To reduce the opportunity for disease spread through nose-to-nose contact while cattle are grazing, inspect your field boundaries, says Mr Rodgers.
He says: “A separation from your neighbouring cattle fields of at least three metres is recommended. Also check your fencing: is it robust enough to prevent cattle escaping into the next field and mingling with another herd? Where fields are next to, or include, woodland or scrub inhabited by badgers or deer which could harbour TB, consider whether these areas could be put down to other crops or grazed by non-bovines. If there are populations of badgers present around a farm, securing feed stores should be a priority, closely followed by cattle housing and feed areas. Although difficult, it is always possible to secure buildings,” says Mr Rodgers. “Badgers can access through any gap greater than 10cm - the height of most mobile phones.”
Although passive fencing is best, to prevent badgers accessing maize silage clamps and feed stores, Mr Rodgers recommends using electric fencing. He suggests using three strands at 10cm (4in), 15cm (6in) and 20cm (8in) from the ground.
Reducing contact at pasture is much more difficult, says Mr Rodgers.
“Recent evidence shows nose-to-nose contact between badgers and cattle is rare, so the main risk at pasture is probably badger urine and faeces, which are concentrated around setts and latrines. Fencing off these areas is well worth the effort, but remember to do it in a way so an area can be cut back to prevent it reverting to scrub, which would cause the latrines to be moved further into your fields.”
Any livestock transport vehicles, cattle crushes or slurry and manure equipment which are shared between farms or hired-in, should be thoroughly cleaned and disinfected before being introduced to stock.
Manure, slurry and dirty water from another farm are also potential sources of bTB and should not be spread on livestock pasture. Mr Rodgers says use of foot dips by visitors and staff is another overlooked safety precaution which can be taken against disease spread.
These security precautions are relevant not only for bTB, but for infectious diseases such as BVD and leptospirosis, adds Mr Rodgers.
Whether you are on a farm which is in the clear from TB and wanting to expand your herd, or looking to replace stock lost in a recent TB shutdown, it is important to follow biosecurity procedures when bringing new cattle to the farm, advises Mr Rodgers.
He says: “A pre-movement TB test carried out on animals before they move to a farm may identify cows with TB lesions at the time, but a recent clear whole herd test is better evidence. However, TB is a slow chronic disease, and it takes time for infected animals to become detectable. This means it is still possible they could be TB-infected, but not react to the skin test. So do not rely just on one pre-movement test. Instead, when the animals arrive on your farm, quarantine them for at least two months, then test again.”