Egg Industry - April 2018 - 16
16 ❙ EggIndustry
PULLET COCCIDIOSIS VACCINATION
allow them adequate space. Try to
move birds to a lower tier as their
exposure level will be more consistent with birds above them.
Paper materials should be divided
and moved with chicks to the new
cages to continue the cycling process.
In aviary systems, papers should be
moved to the floor when pullets are
allowed floor access.
Measuring immune response
is an important part of all vaccination programs. For coccidiosis vaccines, submitting fecal
samples to a laboratory for oocyst
counts is used to evaluate adequate immune response.
Laboratories provide results as a
total of species combined expressed
as OPG (oocysts per gram) of fecal material. Kelli Jones, DVM,
MAM, manager of poultry technical services at Ceva, said: "OPG
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counts are the best tool as they tell
the story of what's happening in the
pullet house. Use this tool to monitor the immunization process and
fine tune your program."
There are two schools of thought
on frequency of sampling. Some feel
that samples taken at days seven,
14, 21 and 28 (at times extending
to include a 35-day count) correlate
well with peak oocyst cycling times.
Others recommend sampling every
three days starting at day seven and
continuing until day 37 for routine
monitoring (or up to day 42 when
first establishing a coccidiosis vaccination program).
Initial counts often are relatively
low, especially in caged pullets.
More frequent, longer sampling
provides a more detailed picture of
cycling (often smaller increases are
noted as different species cycle at
different time points).
Some coccidia species require three
or four cycles to establish immunity, so
depending on the species included in
the vaccine and the house environment,
variation is expected. Vaccine titer and
efficacy of vaccine administration also
affect oocyst counts.
If initial oocyst counts are
higher than expected due to excessive cycling, watch closely for signs
of a coccidiosis break when treatment with a full dose of amprolium
Testing of sprayer calibration ensures proper coverage of chicks. Dr. Kelli Jones
www.WATTAgNet.com ❙ April 2018