Whether crows have anything to do with the level or type of IB pressure is wide open for discussion at egg producers’ nearest café. Meanwhile, Sommer says, he isn’t taking any chances.
Added protection
To provide the broadest
protection against IB, he builds
vaccination programs around
a concept called Protectotype,
which involves using specific IB
vaccines in the same program,
at specific times, for added
cross-protection against different
variants, including QX.
“Infectious bronchitis is rather
tricky,” he says. “If you use the
Ma5 vaccine, it covers the
Massachusetts-serotype virus.
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.”
As a consulting veterinarian
for Schropper, a leading layer
multiplier that supplies readyto-
lay pullets to more than 40%
of Austria’s layer market and
covers more than 80% of that
country’s day-old pullet market,
Sommer and his veterinary
colleague manage the health
program for 80,000 breeders
plus a hatchery that produces 7
million birds a year. In addition,
they consult with about 60
independent egg producers in
Austria and work with clients
in Hungary, Slovenia, Croatia,
Montenegro, Albania and
Bulgaria that buy day-old chicks
from Schropper.
For all of these birds, Sommer
says, IB looms as a “two-fold
problem” that affects the
reproductive and respiratory
systems. “It’s more a respiratory
disease in young birds and a
reproductive disease in older
birds,” he says.
Losses of 50%
When QX came on the scene in
2006, many producers in the
area suffered production losses
up to 50%. The QX outbreaks
returned in 2008, but the
variant has been relatively
quiet since then — partly
because producers are taking
more strategic measures to
ensure broad protection
against all IB viruses.
“The main difference now is
that we use the Ma5 vaccine at
day 1 in the hatchery and 4/91
at day 14,” he says. “With these
two vaccines, we’ve been really
successful in preventing any
major IB problems.”
'Insurance Policy
In addition, Sommer recommends
vaccinating with H-52,
another live IB vaccine, at 10
weeks and then coming in
again with 4/91 at 14 weeks.
At 17 weeks, when birds are
being transferred, he vaccinates
with an inactivated vaccine
that provides additional
protection against IB variants,
plus Newcastle disease,
egg drop syndrome and
avian pneumovirus.
“I look at the killed vaccine as
an insurance policy,” Sommer
explains. “In my opinion, with
this vaccine, you get more
stable birds that are able to
withstand challenges a lot
easier because they have
antibodies against the major
diseases of concern in our area.”
After week 26, Sommer urges
producers to revaccinate with
the live Ma5 and 4/91 vaccines,
usually alternating them every
6 to 7 weeks.
“With the live vaccines, you
get local immunity at the
oral mucosa, nasal mucosa
and ocular mucosa,” he says.
“Those areas — the ocular
one, in particular — are main
entrance ports for IB. So, on
top of vaccinating them with
a killed vaccine at transfer,
we run a really successful
revaccination program.”
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