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Contact:
Skip Derra, News Service, (515) 294-4917
AGRICULTURE, VETERINARY MEDICINE AND
NATURAL RESOURCES NEWS FROM IOWA STATE UNIVERSITY
AMES, Iowa --.
SENTINEL CHICKENS KEEP A BEADY EYE ON VIRUSES
Each summer for the last 24 years, chickens have been the watchdogs for the
arrival in Iowa of mosquito-borne encephalitis. The birds are the key to an
ISU-coordinated early warning system for the disease. Each year new flocks
of about 10 birds are established in nine areas around the state. They are
housed in places like a nature conservatory, a park, a sewage treatment
facility and a Department of Transportation facility. City or county health
officials care for the birds, which ISU supplies as six-week-old chicks each
spring. Local officials regularly take blood samples from the chickens
throughout mosquito season. The blood is tested for the presence of
antibodies to encephalitis viruses. If antibodies are found, it means the
chickens have been bitten by virus-carrying mosquitoes. ISU then alerts
communities to take extra precautions against mosquitoes.
Why chickens? "In nature, the viruses cycle back and forth between mosquitoes and wild birds," says Wayne Rowley, the entomologist who coordinates the program. "The problems occur when mosquito populations get so high that the mosquitoes move from feeding on birds to humans. We used to capture wild birds to test, but that was too time-consuming. Chickens work much better." Where the viruses originate, in bird or mosquito, is a chicken-or-egg question. "There are theories for both, but none are proven," says Rowley. "Some believe the viruses overwinter in cold-blooded animals like frogs or snakes." So far this summer there have been no cases of encephalitis. Eight to 12 cases of La Crosse encephalitis are reported in Iowa each year. Contact Rowley at (515) 294-1573, or Ed Adcock, Agriculture Information, (515) 294-2314.
The new device uses fluorescent spectroscopy, which identifies contamination
by exposing it to one color of light and detecting fluorescence, or
re-emitted light, from the fecal material. Besides providing increased
sensitivity over visual examination, every carcass could be scanned during
processing to determine which ones are contaminated and need to be treated.
This would reduce the number of contaminated carcasses that slip through the
system undetected. The new patented system can be built in a variety of
monitoring configurations that could be adapted to the inspection and
process control development needs of each packing plant. Tests in meat
processing are being planned. Contact Mark Rasmussen, Animal Science and
National Animal Disease Center, (515) 663-7350; Tom Casey, USDA/Agricultural
Research Service and the National Animal Disease Center, (515) 663-7726; or
Ed Adcock, Agriculture Information, (515) 294-2314.
Iowa State homepage
University Relations, online@iastate.edu
Iowa State University and USDA scientists have developed a hand-held
prototype of a detector that makes it easier to spot fecal contamination on
meat carcasses. Meat inspectors typically rely on visual inspection of
carcasses at processing plants. But bacterial contamination of carcasses is
invisible to inspectors. Sampling occasional carcasses does not detect
contamination on every carcass.
ISU FINDING WAYS TO RESTORE IOWA WOODLANDS
For the past two years, botany graduate student Cathy Mabry has studied the
diversity of foliage plants under the tree canopy in central Iowa woods.
Many of those areas have recently been grazed by cattle causing the
disappearance of essential plant species. Mabry established plots in
woodlands throughout central Iowa. She has cataloged plants growing in the
plots and has found different species in grazed areas than in ungrazed
plots. She is looking more intensively at 17 species to determine
reproductive characteristics such as seed size, seed germination, emergence
and dispersal. Seven of those species are common in central Iowa woods, both
grazed and ungrazed, and 10 species are rare in the same areas. She has
found that the rare species commonly produce fewer, but bigger seeds than
the common species. She believes that if the rare species' seeds get to the
desired area, they will grow. Mabry is testing this theory by planting seeds
in three different areas -- a grazed plot, a restored woodland and an area
where the species do not currently grow. This information will help Mabry
and others determine which species will re-establish on its own and which
will need to be actively restored. Mabry has worked with owners of woodlands
and has found many who are interested in what plants are on their property
and what could be established. Woodland restoration encourages diverse
plants that help maintain the diversity of herbivores and insects. Don
Farrar, a botany professor, is working with Mabry. Contact Mabry, (515)
294-3522; Farrar, (515) 294-4846; or Megan Kuhn, Agriculture Information,
(515) 294-2957.
EXHIBIT SHOWCASES IOWA AGRICULTURE'S RICH HISTORY
Did you know ISU horticulture professor Griffith Buck named and released 87
roses? Or that the first soybean planted in Iowa was used in an ornamental
garden in 1852? These facts and more will be on display as the ISU College
of Agriculture takes a look back and ahead during the 1999 Iowa State Fair.
The theme of this year's exhibit is "Iowa Agriculture: A Rich Heritage -- An
Exciting Future." A collection of facts and photos about Iowa agriculture
and Iowa State's contributions over the past century will be on display.
There also will be activities for people of all ages at the exhibit.
Visitors can create their own farm scene using rubber stamps. They can also
test their knowledge of Iowa agriculture with a quiz. A computer will be set
up for visitors to explore ISU with an interactive CD-ROM about the
university. Adults can sign up for daily prize drawings. The fair runs Aug.
12-22. The College of Agriculture display is on the second floor of the
Agriculture Building. Contact Megan Kuhn, Agriculture Information, (515)
294-2957, or Barb McManus, Agriculture Information, (515) 294-0707.
SEED HEALTH EXPERTS FROM 24 COUNTRIES ARRIVE IN AMES
More than 120 seed-disease experts from 24 countries will meet in Ames, Aug.
16-19, to discuss international seed health issues. The third Seed Health
Symposium, which is held every three years, is organized by ISU's Seed
Science Center and the International Seed Testing Association's Plant
Disease Committee. Attendees are seed pathologists working for universities,
government agencies and industry. They work to ensure seeds are free of
disease, which is a key aspect of international trade and of crop
agriculture around the world. Among the topics to be discussed are
standardization of seed health tests; new seed-borne diseases; and new
testing methods. Contact Denis McGee, Plant Pathology, (515) 294-6821, or Ed
Adcock, Agriculture Information, (515) 294-2314.
TRI-STATE TOUR FOCUSES ON DAIRY INDUSTRY EXPANSIONS
Dairy producers, representatives of the ag industry and the general public
can check out the expanding dairy industry in northwest Iowa and the Dakotas
on a three-day bus tour Aug. 17-19. Ten dairy facilities, with herds from 60
to 1,400 cows, will be visited. "Participants will see a variety of
facilities, business styles and dairy management systems," said Magdalena
Kurz, ISU Extension dairy specialist in Orange City. "They'll be able to
visit with the host producers to discuss production and management
technology as well as to learn about the future educational needs of the
dairy industry." For more information and registration, contact Kurz at the
Sioux County Extension Office, (712) 737-4230, or Jolene Stevens, Extension
Communications, (712) 274-0048.
SIMULATED UDDER MAY SAVE PIGS FROM CRUSHING
Farrowing stalls help reduce the incidence of pig crushing, but they don't
completely eliminate the problem, according to Don Lay, assistant professor
of animal science at Iowa State University. Because pigs are attracted to
the feel, heat and odor of a sow's udder, Lay came up with a way to try to
reduce the danger of pigs being crushed, and keep baby pigs warm and
comfortable at the same time. He created a simulated udder by putting a
pillow, a heating pad and two hot water bottles inside a pillowcase, and
placing the entire piece to the side and slightly back of the sow. A piece
of cloth that had been wrapped around the sow's midsection for at least
three days prior to farrowing was removed and wrapped around the simulated
udder, and a heat lamp was hung directly above it. Behavior of the sows and
their pigs in test and control groups was recorded by time-lapse
photography. Although the number of pig-crushing incidents was not different
between the two groups, it was clear that pigs preferred to use the
simulated udder compared to only a heat lamp in the control group. Lay said
initial results are promising, and plans more studies to determine the pigs
attraction to the simulated udder. Contact Lay at (515) 294-2088, or Sherry
Hoyer, Iowa Pork Industry Center, (515) 294-4496.
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Copyright © 1999, Iowa State University, all rights reserved