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BOV INE TB
SUMMER 2012 ISSUE
LIVESTOCK MATTERS
14
On-farm
biosecurity
measures
In TB areas, or where badgers are present,
then there is the possibility of TB-infected
badgers coming into contact with cows at
grass. However, many other risks can
be minimised or prevented by taking
appropriate action.
Cattle can become infected with bTB
from other cattle in a number of ways; by
co-grazing, (for example on common land),
shared housing; at shows; returns from market;
and grazing/housing away from home
premises with direct (nose to nose) or indirect
(e.g. shared water) contact with other herds.
To reduce the opportunity for disease spread
from nose to nose contact whilst cattle are
at grass, inspect your field boundaries; a
separation from your neighbouring cattle fields
of at least 3 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 that
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
on and around the farm, securing feed
stores should be the main priority, closely
followed by cattle housing and feed areas.
Although difficult it is always possible to
secure buildings. Badgers can access through
any gap greater than 10cm (the height of
most mobile phones), so checking entry points
(figs 1-3) is recommended.
Although passive fencing is best, to prevent
badgers accessing maize silage clamps and
feed stores, it may be necessary to use electric
fencing (three strands at 10cm, 15cm and
20cm from the ground).
Reducing contact at pasture is much more
difficult. If possible, avoid grazing cattle near
to setts or latrines if they are not too extensive.
Any livestock transport vehicles, cattle crushes
or slurry and manure equipment that are
shared between farms or hired in, should be
thoroughly cleaned and disinfected before
introducing your stock to them.
Manure, slurry, and dirty water from another
farm are also potential sources of bTB (and
other) infection and should not be spread on
livestock pasture.
The use of foot dips by visitors and staff is
another overlooked safety precaution that can
be taken against disease spread.
The above security precautions are relevant
not only for bTB, but also for infectious
diseases such as BVD and leptospirosis.
Buying in cattle
Whether you are on a farm which is in
the clear for TB and wanting to expand
your herd number, or looking to replace
stock lost in a recent TB shutdown, it is
still important to follow biosecurity
procedures when bringing new cattle
to the farm.
A pre-movement TB test carried out on
animals before they move to the farm
will identify any that have TB lesions at
that time. However, TB is a slow chronic
disease, and it takes time for infected
animals to become detectable. This
means it is still possible that they could
be TB-infected, but not react to the
skin test. So don't rely just on one
pre-movement test. Instead, when the
animals arrive on your farm, quarantine
them for at least 2 months, and then
test again.
MARKABOND/shutterstock.com
Figure 1
Figure 2
Figure 3