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.
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.”
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
“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.”