Experimental Vaccine Stops
Shipping Fever in Feeder Calves
ARS-developed experimental vaccine
should be very effective in cattle against shipping fever, the leading cause of
illness and death in U.S. feedlots.
vaccine was created by deleting a large piece of a specific gene from bacteria
that cause shipping fever. When this gene segment is removed, the bacterium no
longer causes pneumonia in cattle, but does elicit immunity. Veterinarian
Robert E. Briggs and microbiologist Fred M. Tatum at the
Animal Disease Center in Ames, Iowa,
live vaccine without foreign DNA.
Biotechnology Research and Development
Consortium of Peoria, Ill., funded part of the research and applied for
several patents on the vaccine. The vaccine has not yet been approved by the
U.S. Department of Agriculture's (USDA)
Animal and Plant Health Inspection Service (APHIS) for use in the United States.
disease costs cattle producers more than $1 billion annually in losses. It's
also called "shipping fever" because calves develop it about one week after
being shipped to feedlots where they finish growing. Shipping fever results
from an interaction of stress, the animal's immune system, and infectious
pathogens. Bacteria invade the animal's lower respiratory system, causing
pneumonia. The respiratory disease reduces the animal's weight gains, adversely
affects feed efficiency, increases antibiotic costs, and decreases meat and
hide quality, in addition to causing cattle deaths.
In a 1999 study of the top 12
cattle-producing states, the USDA estimated that 97.6 percent of feedlots had
at least one animal with shipping fever.
ARS-developed vaccine could be administered by a variety of routes, including
standard injections or as a novel oral vaccine.
The oral vaccine
protects the animals within three to four days after being added to feed,
instead of the seven-to10-day wait required with injectable vaccines. In a
field trial with the new experimental vaccine, the mortality rate among
vaccinated high-risk calves was 4 percent, compared to 16 percent among
unvaccinated ones. The bacterium Mannheimia haemolytica, the leading
source of shipping fever, was the culprit in all of the deaths of the
unvaccinated animals, but killed none of the vaccinated ones. During the first
28 days on feed, low-risk calves that received the oral vaccine had a 25
percent higher weight gain on average than untreated cattle. Additional field
trials have confirmed the weight-gain advantage during the first 35 days of
A major drug firm
has licensed the technology and hopes to market a multivalent injectable
vaccine using the genetically-modified strains of Mannheimia (formerly
Pasteurella) haemolytica and P. multocida.
Robert E. Briggs or
Fred M. Tatum,
The first national
for dairy cattle fertility will help breeders select for reproductive
ARS scientists are studying the amounts of
dust produced in
various sections of cattle feedlots and measuring the dust's contents for
An ARS scientist co-developed an improved method
farm-raised catfish with oxygen during a crucial production stage.
Thanks to an ARS researcher, a
compound from a
weed may help catfish farmers battle the ram's horn snail.
ARS studies show remote sensing matches
grazing animals with
the right forage more quickly and more easily.
Central and Northern Great Plains cattle could
soon be enjoying three
new wheatgrass cultivars developed by ARS scientists and cooperators.
Swine at various locations in the country
levels of nutrients from the same feed mixtures, according to results from
a collaborative study.
A new test developed by an ARS scientist tells
trout breeders and researchers which fish are
inclined to develop more muscle and less fat.
Kenneth E. Overturf
ARS researchers are gaining
insight into trout
genetics so they can breed faster-growing, disease-resistant fish.
Caird E. Rexroad III
724-8340, ext. 2129
A new technique developed by an ARS scientist
helps keep Double-crested
cormorants from plundering catfish farm ponds.
673-4483, ext. 290
Janice M. Miller, a veterinarian at the
Animal Disease Center, was one of two scientists this year inducted into
the ARS Hall of Fame. Miller was recognized for
in understanding, diagnosing and controlling bovine leukemia, transmissible
spongiform encephalopathies and other chronic infectious or zoonotic diseases
of ruminant animals.
Louis Gasbarre, a microbiologist with the
Immunology and Disease Resistance Laboratory in Beltsville, MD, recently
received the 2003 Distinguished Veterinary Parasitologist Award of the American
Association of Veterinary Parasitologists. The award is the highest honor
bestowed by the scientific society. According to their Web site, the award
"honors contributions to veterinary parasitology that are widely recognized
internationally as significant and important to the understanding and control
of parasitic diseases of animals."