"Prions are proteins that occur in the
brain of every animal," explained Jan Novakofski, a professor in the
U of I Department of Animal Sciences and one of three lead
researchers on the project. "In rare cases, these prions change into
something that causes brain cells to die -- a poison, if you will.
Once the process -- prion disease -- starts, it cannot be stopped,
and to date no one has found a way to inactivate these agents. Prion
disease in animals and humans is terminal."
Several years ago, the British beef
industry was devastated by mad cow disease, a prion malady. A number
of humans fell victim to the disease after eating beef infected with
mad cow disease and contracting the human version, Creutzfeldt-Jakob
disease, or CJD. This fall, chronic wasting disease began showing up
in deer populations in Illinois, likely migrating from Wisconsin,
where the disease has had a major impact on the hunting and tourism
industry.
"There are many unknowns about these
prion diseases," said John Killefer, an associate professor of
muscle biology in the Department of Animal Sciences and also a lead
researcher on the project. "No one understands where the animals are
picking up the disease and how they are passing it on."
Nohra Mateus-Pinilla, an assistant
professional scientist and epidemiologist with the Illinois
Department of Natural Resources' Illinois Natural History Survey and
also a leader in the prion project, says it is important to
establish what prompts the prions to turn bad in the first place and
how the process becomes infectious.
"All three of us were interested in
prion diseases, so we decided to put our expertise together and
develop a multidisciplinary research approach that would benefit the
livestock and agricultural industry, as well as conservation and the
protection of our natural resources," she explained. "Our work is
partly focused on chronic wasting disease, but we are also looking
at natural resistance to other prion diseases, like scrapie in sheep
and mad cow disease and its human form, CJD."
The project also involves researchers
from the U of I College of Veterinary Medicine and other state and
federal agencies.
"Our long term goal is to understand
mechanisms of CWD transmission and highlight possible intervention
and prevent strategies," Mateus-Pinilla said.
Four broad goals are driving the
research, the three explained. The first is the generation of a
"risk map" that will aid the Department of Natural Resources in
preventive management of CWD. Based on genetic data first developed
at the Rocky Mountain Laboratory in Colorado, the researchers' map
will indicate areas in Illinois where deer have a "genetic
susceptibility" to CWD.
"This map will overlap ecosystems
favored by deer and deer densities in urban and rural Illinois, as
well as CWD-positive and negative deer, land cover data, and
Illinois deer genetic fingerprinting," said Mateus-Pinilla. "This
information will help the development of science-based deer herd
management using spatial dynamics of CWD in a host-environment
framework."
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A second goal involves determining if
there are environmental reservoirs that favor development and
transmission of the disease.
"Scientific evidence suggests that
prions may persist in infectious environmental reservoirs outside
deer," said Killefer. "These reservoirs may include soil,
vegetation, insects or other animals. If we can determine where
these reservoirs are, such knowledge may provide critical control
points for intervention and prevention."
.Scientific evidence has already
demonstrated the ability of infectious prions to jump species. At
the same time, the researchers will address the transmission
dynamics of interspecies prion infection.
"The potential for interspecies
transmission highlights the need to assess the potential
transmission of prion diseases from wild species into livestock
species -- and vice versa -- as well as their transmission to
humans. The first step is therefore to understand mechanisms of
disease transmission," said Mateus-Pinilla.
The first three goals will help lay the
groundwork for the fourth -- the development of prevention
strategies.
"Studies in sheep have demonstrated
that certain genetic backgrounds are highly resistant to scrapie
infection," said Novakofski. "This type of genetic resistance has
not been identified in cattle or pigs. At the same time, mouse model
systems have shown that gene therapy can, in effect, knock the prion
protein out.
"We'll look at the potential of
developing a genetic prion 'knockout' in cattle that will be
naturally resistant to infection and unable to transmit the disease
to other animals or humans."
As the United States has remained
relatively isolated from prion disease problems until the spread of
chronic wasting disease from western deer populations into the
Midwest, there has been little funding. The three scientists see
that as changing.
One reason is the potential economic
impact on the Midwestern as well as the U.S. livestock industry if
CWD jumps species or if mad cow disease breaks out in the United
States. The standard approach -- and currently the only one -- is to
kill the infected animals and quarantine the area. In Canada, some
elk breeders whose animals were found to have CWD have not only been
banned from livestock production but also prohibited from growing
crops on their land.
Killefer noted that although pigs can
be infected by artificial means, no one has been able to demonstrate
the natural occurrence of prion diseases in swine. Any prion
outbreak among Illinois livestock could have serious economic
repercussions for the state's agribusiness sector.
"Mad cow
disease, although controlled in Great Britain and yet to reach the
United States, continues to spread in Europe and Asia," said
Novakofski. "It seems prudent to redouble our efforts to deal with
the prion diseases."
[University
of Illinois news release]
[Click here for related article, "CWD cases stand at seven in
Illinois."]
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"These factors will likely more than
offset the effect of a slowdown in the rate of domestic processing
of soybeans," said Darrel Good. "The slower rate of processing has a
more positive impact for soybean meal prices than for soybean oil
prices, due to the relative product yield from the 2002 crop.
"For the period September through
November 2002, the average oil yield per bushel of soybeans
processed was 11.35 pounds -- 0.21 pounds, or 1.9 percent, higher
than the average yield of a year ago. On the other hand, the average
meal-plus-hulls yield was 47.12 pounds -- 0.37 pounds, or 0.8
percent, lower than the average yield of a year ago."
Good's comments came as he reviewed the
rebound in soybean prices after a sharp decline following the
bearish information in the USDA's Jan. 10 reports. March futures
traded to $5.44 following the report but settled at $5.69 on Jan.
24. November futures recovered from a low of $5.025 to settle at
$5.285 on Jan. 24. The average spot cash price in central Illinois
declined to $5.41 on Jan. 16 but rebounded to $5.615 on Jan. 24.
That price was 14 cents below the early January high.
"The recovery has been mostly driven by
higher soybean meal prices, but a number of other factors have
contributed," said Good.
These include projections of a decline
in U.S. soybean acreage in 2003, drought conditions in important
producing areas of the United States, thoughts that widespread low
temperatures are driving domestic meal feeding higher, hot weather
in parts of Argentina and a rapid pace of U.S. export sales.
More information about prospective
acreage and yields in the United States in 2003 will be revealed
over the next few months, as the USDA releases its "Prospective
Plantings" report on March 31 and spring weather prospects become
clearer.
"There are three sources of information
about the pace of U.S. soybean exports: the USDA's weekly 'Export
Inspection' report, the USDA's weekly 'Export Sales' report, and
monthly estimates by the Census Bureau," said Good. "The Census
Bureau figures are the official estimates and are reflected in the
USDA's historical supply and consumption estimates.
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"It is not uncommon for these three
sources to have different estimates. This year, however, there is a
very large difference in the estimates of soybean exports from these
sources. Census Bureau estimates are only available for the first
three months of the 2002-03 marketing year -- September, October and
November 2002. Cumulative exports for those three months are
reported at 297.6 million bushels -- 50 million bushels, or 14.6
percent, less than during the same three months last year."
In contrast, Good noted, the USDA
"Export Sales" report showed cumulative exports during that period
at 317 million bushels -- 18 million bushels, or 5.4 percent, less
than indicated for the same three months last year. Finally, the
USDA's "Export Inspection" report showed cumulative shipments
through November 2002 at 339 million bushels --16.8 million bushels,
or 4.7 percent, less than during the same period last year.
"A large difference among export
estimates has occurred before, most recently in 1998-99," said Good.
"In that year, the difference resulted in the USDA carrying a very
large estimate of residual use of soybeans in the supply and
consumption balance sheet. It will be important to see if the Census
Bureau estimates continue to fall below those from the USDA and, if
so, how the difference is resolved."
The other issue regarding U.S. soybean
exports is the large outstanding sales to China. As of Jan. 16,
2003, the USDA "Export Sales" report indicated that 123.5 million
bushels of U.S. soybeans had been shipped to China since Sept. 1,
2002. That is 21.6 percent more than cumulative shipments at the
same time last year. Unshipped sales to China on Jan. 16 totaled
97.2 million bushels, four times as large as unshipped sales of a
year ago.
"Until those soybeans are shipped,
there is always some concern that the sales could be canceled. That
concern is most prevalent at this time of the year, as the South
American harvest gets under way," said Good.
March 2003 futures may find some
technical resistance in the gap left following the Jan. 10 USDA
reports and at the pre-report high of near $5.85.
"Recent lows
should provide support," said Good. "November futures prices have
already exceeded the pre-report high. Fundamentally, a prospect for
a large South American harvest is still the most limiting price
factor at the current time."
[U
of I news release]
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Scholarship winners will be chosen
based on their commitment to agriculture as a future career,
academic performance, involvement in extracurricular activities,
financial need and work experience. The committee is particularly
interested in candidates who will return to the Logan County area to
pursue their careers.
Applications are available from the
Lincoln/Logan County Chamber of Commerce -- (217) 735-2385;
303 S. Kickapoo St., Lincoln, IL 62656 -- or at any high school in
Logan County.
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Completed
applications are due to the Lincoln/Logan County Chamber office in
Lincoln by Friday, Feb. 28. Applications will be reviewed soon
afterward, and winners will be notified of their award. Winners will
be recognized at the Logan County Ag Day breakfast on Wednesday,
March 19.
[News release]
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