C2B—Ufxastf Farming, Saturday, September 27,1980
NEWARK, Del. - Two
University of Delaware
poultry virologists, Jack
Gelb, Jr., and Jobn K.
Rosenberger, have received
a $40,000 national com
petitive grant to study in
fectious bronchitis, a
respiratory disease of
chickens.
Gelb, a researcher at the
Delaware Agricultural
Experiment Station, says
respiratory tract infections
are a major problem of
poultry producers.
A recent broiler industry
survey estimates that in
fectious bronchitis and other
diseases of.the respiratory
tract are a constant health
threat and economic
problem costing well over $8
million a year on the
peninsula alone.
Infections bronchitis may
well have as much economic
impact on the poultry in
dustry as infectious
Newcastle disease, says the
scientists. It is an explosive
disease in broilers, with a
Ag chemical head
hits handling
of nitrites issue
WASHINGTON, D.C. - A
top spokesman for
agricultural chemicals
Tuesday cited the federal
government’s flip-flop
handling of the nitrites issue
as another example of
regulation by emotion rather
than by sound science.
Jack D. Early, President
of the National Agricultural
Chemicals Association,
offered this view at a House
Agriculture Committee
hearing called primarily to
cross-examine witnesses
from the U.S. Department of
Agriculture and Food and
Drug Administration for
their abortive 1978 decision
to move against nitrites
based on data which was
later provide scientifically
unsound.
In bis criticism of the
government’s handling of
now-vindicated nitrites.
Early testfied that “what is
so very distrubing in this
issue is the unscientific
handling of scientific in
formation by regulatory
officials responsible for
making societal decisions.”
Early offered two
4
r 4
ELECTRIC
FENCERS
SPECIAL SALE
ON PARMAK
Used Units and
New Discontinued
Units
IF YOUR LOCAL DEALER
DOES NOT HAVE IT.
CONTACT
PEQUEA
BATTERIES
RONKS.PAI7F 2
■k Authorized Distributor
& Warranty Station
Scientists win grant to
short incubation period. It.
spreads rapidly and no
treatment is possible during
its acute stage because the
virus does not respond to
antibiotics or other
medication.
Because it weakens their
natural defenses, bronchitis
leaves birds vulnerable to
secondary infections. It is
believed to be one of the
agens that causes air sac
disease, a complicated
condition which affects both
growth and condemnation
rates in broilers. In hens, the
virus can also cause oviduct
damage, thus affecting table
egg production.
There are three diseases
for which chickens are
routinely vaccmated-Newc
astle disease, Marek’s
disease, and infectious
bronchitis.
Unlike the first two, which
have only one kind of in
fection-causing antigen and
so require only one kind of
vaccine, the bronchitis virus
has at least 10 or 12 variant
recommendations for im
provement in federal
procedures for the
regulation of suspect cancer
causing chemicals:
Modify the 1958 Delaney
Clause to allow regulators to
evaluate benefits as well as
risks of suspect chemical
carcinogens.
Place responsibility for
determination of car
cinogenic potential with a
“properly constituted
scientific group devoid of
any regulatory respon
sibility.”
OIL PR ,c f
50' - 65' ■ ® 5
95'
How Much
Will
You Pay?
forms, or serotypes, each
capable of causing infection.
Though chickens in
commercial production are
immunized for one or two of
these serotypes, they can
still contact bronchitis if
they are exposed to any
other variants.
Gelb and Rosenberger’s
grant is to study h&w these
variant viruses occur.
Scientists think that bron
chitis in chickens may
resemble influenza in
humans in that the virus is
always taking new forms,
each slightly different.
When a new flu serotype
develops and causes a
disease outbreak, such as.
the Hong King strain a few
years ago, it may run
rampant until a vaccine can
be developed for its control.
A similar situation may
occur with infectious
bronchitis.
There are several theories
about how new bronchitis
stains emerge, but very little
is actually biown. The work
is difficult to do because it
involves serotyping, is
isolating and identifying,
each form of the virus.
Gelb is one of a handful of
scientists m the U.S. now
study poultry bronchitis
working with this technique.
It is a time-consuming,
expensive process most
people don’t want to tackle.
He says the challenge is to
develop experimental
procedures that will allow
for valid interpretation of
the results. This is basic
research for which the
present three-year grant is
just a start.
“We hope to make the
University of Delaware a
Significant contributor in the
area of infectious bronchitis
serotyping as it already is in
some other areas of poultry
disease research,” says the
virologist.
“If we can get art idea of
how these viruses emerge, it
may be easier to control
infectious bronchitis in the
field. Because of the density
of broiler production on
Deliharva, there’s a
tremendous opportunity for
new serotypes to develop.”
While studying another
disease-air saccuhtis-with
fellow Experiment Station
researchers, Gelb has
already succeeded in
isolating five bronchitis
serotypes, including two
“rather interesting’’
isolates.
GEOTHERMAL
ENERGY
• Utilize The Ground Water Heat on Your Property
... Wells, Ponds, Pools, etc.
40% TAX CREDIT
“We feel present-day
vaccines do not protect
against these two,” he says.
“We’re exploring virgin
territory here, as far as any
previous research is con
cerned.”
If young broilers in the
field are infected with one of
the variant forms of the
virus he’s found, he can
confirm this a few weeks
later by using the new
isolates to challenge live
birds from a broiler house.
If birds are already im
mune, this would imply
previous infection by these
variant serotypes.
This,-in turn, could mean
that these forms of infectious
★ Heat ★ Cool
★ Provide Domestic Hot Water For Less
Than V* The Cost of Oil
★ Air or Hot Water Systems
AVERAGE OPERATING COSTS...LESS
THAN *4OO PER YEAR!
For Information, Contact:
& ASSOCIATES. INC.
bronchitis are contributing
(o poor growth rates and
condemnation from air sac
and other diseases on
Delmarva. If this is the case,
says the virologist, we may
need to develop a new
vaccine.
While conducting research
on this project, Gelb and
Rosenberger will be working
with fellow scientists in the
department of animal
science and agricultural
biochemistry.
They will also work closely
with Paul Allen of the
University’s poultry
diagnostic laboratory at the
Georgetown Station, as weH
as with various industry
representatives.
CM. DAVID
400 N. Race St.
Richland, PA 17087
717-866-7588 (Call
717-272-8580 Collect)
-OR
HAROLD C. FOSTER
Box 96A
Star Route
Huntingdon, PA 16652
814-643-0248
(Call Collect)
(
r