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VACC INAT IONS
SUMMER 2013 ISSUE
LIVESTOCK MATTERS
20
The health of the
sheep
Good sheep health, along with adequate
nutrition and a fully functioning liver are
vital for vaccines to be effective. Fluke can
be a particular problem; as well as direct
liver damage as a result of fluke infection,
fluke can also affect a sheep's ability to
create a response to a vaccine. Vaccines
produce a 'Type 1' immunity and Fluke a
'Type 2', so if there is a Type 2 response,
then the Type 1 response is reduced, or
absent. Therefore, with a moderate to
heavy fluke burden, the vaccine will not
work as well as it should. With the rise in
fluke, this has to be considered in any
vaccination programme.
Stress
Stress triggers a rise in the body's own
steroids, which can depress the immune
system. Vaccinating at weaning is convenient
for us, but it causes great stress to the sheep.
So although it requires extra handling,
vaccinating a week before or a week after
weaning will be of benefit.
Timing vaccinations:
Ewes:
Precise timing is important and will vary according to the
product used and this information should form part of
your regularly updated health plan.
Pregnant ewes should be given a
booster for Clostridial disease and
Pasteurella just prior to lambing. Ideally,
this needs to be about four weeks before
lambing so that enough antibodies are
available in the colostrum to protect the
lamb. However, if you have an extended
lambing period, it might be wiser to split
the timing of this dose, otherwise some
ewes will be vaccinated too early and
some too late.
Boosters:
If fat lambs are sold before October,
they are not likely to need a booster.
However, if they are kept and particularly
if they are either housed or moved to
winter grazing, then using a booster for
Pasteurella prior to this is a sensible plan.
There is a regular rise in pneumonia
caused by Biberstenia trehalosi in these
months, so it is worth discussing this
with your vet.
Bought-in sheep:
It is common for farmers to refer to
bought-in sheep as being ‘in the system’
for the clostridial vaccines. This can be
misleading so if in any doubt, it's always
best to start again; the ‘extra’ boosters
will do no harm.
Replacements:
For sheep put to the tup in the year they
are born; they should get a booster with
the rest of the ewes prior to lambing.
This will be within 12 months of their first
course and all is well. However, if they
breed the following season, they will
need a booster dose a year after their
last injection. It is not uncommon for these
replacements to miss this dose in the late
summer/early autumn, but be included
with the ewes before lambing. However,
this means that there has been a gap in
their immunity, so they will not produce a
good response and their colostrum will
contain fewer antibodies. Therefore it is
probably easier to give these lambs a
booster at the same time as the ewe
flock even though they are not lambing
themselves that year.
Lambs:
Typically vaccinations should be done at
12 weeks of age, followed by a second
dose 4-6 weeks later. However, if
Pasteurella is a problem, lambs may
need vaccinating from about four weeks
old. The timing of these doses relates to
how long the antibodies from the
colostrum last in the lamb. Death from
pulpy kidney is common in lambs that
had no vaccination at about 10-12
weeks of age.
Tups:
Don't forget the big lads! This is
especially true if they are kept away
from the main holding.
Photo Courtesy of Sterimatic
Photo Courtesy of Sterimatic