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SHEEP MED I C INES
Drenching equipment should be calibrated
regularly
SPRING 2016 ISSUE
LIVESTOCK MATTERS
8
pregnancy. Here, ewe nutrition is key to limiting
the peri-parturient effect. The management of
ewes through this period will depend very
much on the specific farming system and
should be discussed with the farm’s vet.
‘Lambs will likely require treatment for worms to
help maintain growth rates before being sold
for store or for slaughter. There are currently
three broad spectrum anthelmintic groups avail-
able for the routine worming of lambs
(See
Table 1)
. The use of two or more of these
anthelmintic groups – white, yellow and clear
drench – may be required during any one sea-
son. The dosing interval between these prod-
ucts will depend on the product used and the
pasture management on the individual farm.’
Ed adds: ‘Not every dirty-tailed sheep or
lamb has worms! So if in doubt as to whether
treatment is required, faeces samples should
be collected and checked to see if worm
eggs are present.
‘Pasture management and rotational grazing
also have a role to play in limiting reliance on
wormers.’
Quarantine dose
To minimise the chance of bringing resistant
worms onto the farm, all purchased sheep
should be quarantined and drenched
with one of the new categories of wormer,
a purple or orange drench. This should only
be done in consultation with the farm vet,
and the protocol should be part of the flock
health plan.
Table 1:
Classification of anthelmintics
Flukicides
A number of products are available for
the treatment of liver fluke, with different
products killing different stages of fluke.
‘The best product to use will depend on
the farm history and the time of year. The
fluke challenge can vary each year, so
treatments need to adapt and change
accordingly,’ says Ed.
‘NADIS and SAC both provide fluke
forecasts, and this information will be
used by the farm vet, to formulate an
appropriate fluke control programme.
‘Faeces sampling to determine fluke
infestation levels can be useful. Bulk
sampling can be used to keep costs down;
faeces from 10 individual animals are
submitted and then pooled at the lab.
This composite sample is then assessed
for the presence of fluke eggs.
‘Eggs are most commonly shed between
10 and 12 weeks after infection. So
caution needs to be employed as an
animal may have a high immature fluke
burden but not be shedding eggs yet.
Treatment decisions should take account
of all the available information, and be
based on how the sheep are doing.’
Antibiotics
‘Antibiotic use on farms is coming under
increasing scrutiny. Antibiotics must only
be used following veterinary advice. It is
essential to ensure the correct dose, route
and timing of administration to avoid the
risk of resistance developing. Adhering to
the correct product guidelines will maximise
success rates.’
Flock health plan
Ed says: ‘The use of any medicines on-farm
should be integrated into disease treatment
and prevention plans and form part of an
overall health plan for a flock. This should
be reviewed annually with the farm vet
because new products may have become
available, and disease challenges fluctuate.
‘With veterinary input, a planned approach
will ensure that the right products are used
at the right time and at the right dose,
prevent time and money being wasted, and
maximise profitability and production.’
Medicine storage
Different products require different care in
storage to ensure product efficacy. Storage
information can be found on the product
packaging.
Vaccines need to be stored in a fridge – but
never in the fridge door, as this area has the
greatest temperature fluctuation. They
should be transported from the place of
purchase in a coolbag, or similar, with a
cold pack inside. Farm fridges should have
a maximum/minimum thermometer inside to
monitor temperature, and this information
should be recorded weekly.
Wormers and antibiotics need to be stored
at room temperature. But beware of keeping
them in unheated farm buildings in the
winter, as many products will be rendered
ineffective if subjected to frost or extreme
temperatures.
Expiry dates also need to be monitored
so that stock can be rotated; this ensures
out-of-date medicines are not used.
When indicated, store medicines in a refrigerator
and check the maximum and minimum
temperature of the fridge
Checklist for success:
•
Calibrate dosing equipment
•
Dose for the heaviest animal
•
Utilise faecal worm egg counts or
targeted selective treatment based on
weight gain.
•
Use product at the correct interval
Broad spectrum anthelmintic groups
Benzimadazoles
White drench
Levamisoles
Yellow drench
Macrocylic Lactones
Clear drench
Quarantine wormers
Abamectin and Derquantel Purple drench
Monepantel
Orange drench
Checklist for success:
•
Calibrate dosing equipment
•
Dose for the heaviest animal
•
Check product efficacy where
resistance is suspected.
•
Use a product appropriate for the time
of year