Volume 22 • Issue 02 • 2018
If more than one approach to disease prevention
is used effectively in combination, up to a 100%
of a vaccinated herd can be protected.
It must still be appreciated that there is a large
variation between the prevention approaches
needed for all the different diseases that affect
dairy animals. Some industry specific disease like
claw infections will always occur, but need to be
managed in such a way that as not to exceed a
set limit.
Disease Prevention Strategies
In most instances more than one approach to
disease prevention must be employed in order to
effectively control a disease, especially in a dairy
herd that needs to produce on a daily basis.
Controlling a very complex disease like
Staphylococcus areus mastitis in a herd is such
an example.
1. Firstly the general disease resistan ce must be
improved by good parasite control and good
nutritional management, especially during
the dry period and after calving. On its own,
this approach cannot control the spread of
this infectious form of mastitis.
2. Secondly the specific resistance against
this disease-causing organism must be
stimulated. This was not possible before but
with a new effective vaccine on the market,
this is possible.
3. Thirdly the level of exposure must be
decreased through identification and culling
of chronically affected carrier animals and
the use of effective dry cow mastitis remedies
where prescribed by the herd veterinarian.
Prevent Disease Exposure
The fourth and final approach to disease
prevention is to prevent exposure completely.
This is most important in the case of diseases
for which there are no vaccines, no treatment
available, or where the herd is currently free of
this disease.
Most of our state controlled diseases can be
named as examples:
•
•
Bovine tuberculosis
Foot and mouth disease (controlled without
vaccination in the disease-free area of South
Africa)
Certain uncontrolled diseases from which the
herd is currently free must also be prevented by
this approach, for example Johne’s disease.
In this case a large part of the herd is very
susceptible, either because the animals were
never exposed to this disease, or because no
vaccination is available to increase the specific
resistance of the animals.
General resistance will not protect all the animals
in the herd against these diseases if new animals
are introduced into the herd.
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