Legendary cyclist Lance
Armstrong once described life
as “a series of false limits.”
“It’s my challenge to explore
those limits,” he added. Then he
went on to win seven consecutive
Tour de France titles.
The poultry industry often
reminds me of Armstrong
because it, too, has a track
record for “exploring limits”
and achieving the unthinkable.
Year after year, flock after flock,
producers keep raising the bar
for feed conversion, growth rate,
egg production, survivability
and uniformity. Numbers that
once seemed unattainable are
now taken for granted. It seems
the more the poultry industry
challenges itself, the more
successful it becomes.
One recent example of the
poultry industry’s resourcefulness
can be seen in its ongoing
battle with infectious bronchitis
(IB). New and potentially costly
variants such as QX are emerging
all the time, challenging
veterinarians and producers to
find new means for control,
often with existing tools.
Good Fit
Through what is known as
Protectotype — where some
strains of IB viruses are highly
effective at inducing cross
protection against other
serotypes — they’ve discovered
that using certain combinations
of vaccines can provide more protection than the IB strain
or strains found in any one
vaccine vial.
One veterinary practitioner in
Austria reports seeing this first
hand in the 80,000 breeders and
millions of pullets under his
care (page 26). “If you use the
Ma5 vaccine, it covers the
Massachusetts-serotype virus,”
says Franz Sommer, DVM,
DACPV.
“If you use the 4/91 vaccine, it
covers the 4/91 type of virus.
But if you use the two of them
together in the same program,
they cover a couple of different
serotypes. Vaccine A plus vaccine
B protects not only against
A and B, but also against
serotype strains C and D.”
When it comes to managing IB,
there also seems to be no limit
to raising the bar for protection.
For example, Paul McMullin,
MRCVS — a consulting veterinarian
for Hy-Line in the UK —
notes that protection induced
by live vaccines used in rearing
should last to 20 to 23 weeks
of age. “The problem…is that
by 20 to 23 weeks, flocks are
coming into lay, “ he says. “That
is a period of high physiological
stress, so it's a very bad time
for birds and they’re very
susceptible to new infections.”
For that reason, after giving
the inactivated combination
IB vaccine at transfer, he now
recommends re-vaccinating
with a live IB vaccine after
7 days — or whenever the
flock has settled into its
new accommodation.
Success by innovation
Scientists are also helping to
develop new ideas for IB control.
At the XVII World Veterinary
Poultry Association Congress in
Mexico, more than 400 poultry
veterinarians packed a meeting
room for a symposium about
Protectotype, where specialists
from five countries shared their
experiences exploring new
programs for managing the
persistent disease.
These innovations are being
used successfully by large
poultry operations. As Richard
Beevis, UK breeder farms
manager at Hy-Line, says, “The
QX variant is becoming more
prevalent in the UK, yet we
haven’t changed our vaccination
program for 12 months. I think
that says something about the
vaccine products we’re using
and when we’re using them”
Once again, it’s all about
exploring new limits. We are
pleased to report on the
industry’s latest feats in this
issue of PRP.
Frédéric David, DVM
Global Marketing Director
Global Poultry Business Unit
Intervet/Schering-Plough
Animal Health
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