
New Test Could Help Breed Edema-Resistant
PigsBy Linda
McGraw July 6, 1999Hog farmers may be able to rear pigs
with a natural ability to resist edema disease caused by an intestinal E.
coli bacteria. Thats welcome news for producers who lose money when
young pigs get sick from a type of E. coli called F18. U.S. Department of Agricultureresearchers in Ames, Iowa, and the Pig
Improvement Company (PIC) of Franklin, Kentucky, cooperatively developed a
DNA-based test to identify pigs genetically resistant to the F18 E. colistrain that causes edema. Rapid growth of F18 E. coli in the 3- to
14-week-old pigs small intestine after weaning leads to edema disease,
characterized by a excessive build-up of body fluids. The F18 strain
doesnt cause disease in humans. This is a natural way of breeding healthier, more disease resistant
pigs. For producers, this strategy is a better alternative than increasing use
of antibiotics in animals. The cost of vaccines and antibiotics cuts into
producers profits, said Agricultural
Research Service Administrator Floyd Horn. ARS is USDAs chief
scientific research agency. ARS microbiologist Julia F. Ridpath at the
National Animal Disease Center in
Ames, Iowa, and Brad Bosworth, who was an ARS veterinarian and is now a group
veterinary scientist with PIC, discovered resistance and susceptibility to F18
is linked to a specific gene. A Swiss scientist, Peter Voegeli, concurrently
made the same discovery. Ridpath and Bosworth have validated their test on more than 500 pigs. Pigs that are resistant to edema disease lack intestinal receptors.
The lack of receptors makes it impossible for this bacteria to stick or attach
to the intestinal wall, said Bosworth. The scientists also identified
another way to reduce the problems caused by the F18 E. coli bacteria:
feed weaned pigs more animal protein in place of soybean meal. This tactic
prevents the bacteria from taking hold in the susceptible pig. The death rate among pigs with full-blown edema disease is about 25 percent.
ARS and the Biotechnology Research and Development Consortium (BRDC) in
Peoria, Illinois, hold a patent on the test. PIC has a worldwide exclusive
license for the commercial use of the technology except in Switzerland. A story about the research appears in the July issue of ARS' Agricultural Research magazine
and on the web at: http://www.ars.usda.gov/is/AR/archive/jul99/pigs0799.htm Scientific contact: Julia Ridpath, ARS
Enteric Diseases and Food
Research, National Animal Disease Center, P.O. Box 70, Ames, Iowa 50010;
phone (515) 663-7372, fax (515) 663-7458,
[email protected]. Story contacts Julia F Ridpath U.S. Department of Agriculture | |