MO-Unmtar Fsmdog, Saturday, dun> 30,1990
Editor’s note: Last week in
Lancaster Farming we intro
duced readers to a new avian
health test facility newly con
structed by the University of
Pennsylvania’s New Bolton Cen
ter. This week we’ll explore the
work being conducted by center
scientists to test for Johne’s dis
ease and how that work may
help farmers.
ANDY ANDREWS
Lancaster Farming Staff
(This is the last of a series.)
KENNETT SQUARE (Chester
Co.) Johne’s disease is costing
fanners a lot of money millions
of dollars per year and they’re
not even aware that it’s affecting
their herds.
‘ ‘Less than 25 percent of the far
mers in the state are not aware that
their cows are infected on their
farm,” said Dr. Robert H. Whit
lock, of the University of Pennsyl
vania’s New Bolton Center.
The center, in cooperation with
Penn State and the Pennsylvania
Department of Agriculture, has
been instrumental in providing the
necessary research, tracking, and
treatment of Johne’s disease in this
area. Breakthroughs in diagnostic
testing capacities allows the cen
ter to delect three times as many
animals as the current test run by
other laboratories.
Johne’s disease affects all types
of cattle. Of particular concern,
especially in counties such as Lan
Conditions Best For Newborns At Center
ANDY ANDREWS
Lancaster Fanning Staff
KENNETT SQUARE (Chester
Co.) Most doctors would agree
that the best place to have a Cesa
rean section (C-section) on a birth
ing dam would be the hospital.
The difference is obvious: It is
better for the mother and the new
born calf to undergo the trauma of
birth at an animal hospital, which
has the proper facilities and medi
cal care, than at the farm.
Surgeons at the University of
Pennsylvania’s New Bolton Cen
ter agree.
"The difference is that the con
ditions are much better here,’ * said
Dr. William Dona wick, professor
of surgery at the George Widener
Hospital For Large Animals at
New Bolton Center. ‘ ‘We have the
help, we have the cow restraints,
and we have special equipment in
case there’s an emergency that
arises.’’
A special emergency staff
remains on-call at the hospital on a
24-hour basis. The hospital
arranges for C-section delivery on
cattle with the farmer.
Cesareans are grouped into two
categories of need, according to
Donawick. One category is diffi
cult births, where the calf cannot
pass through the dam’s birth canal,
or where a calf is stillborn and the
dam cannot deliver the fetus on her
own. The other is an elective C
section where the surgeons believe
it is easier and safer for the new
born and the mother.
“At New Bolton Center, we
have extra people. We have all
these extra things so that the risks
to the dam and calf are much less,’ ’
he said.
The “hospital setting” is best
for both dam and calf. The surgery
is almost exactly the same as
human C-sections.
Overall, the center is perform
ing fewer C-sections this year than
Center Helps Farmers Stop Johne’s Disease
caster and Lebanon (two of the
highest dairy producing regions in
the country), are the dairy cattle
affected and how readily the dis
ease can be passed on to calves.
No treatment
“There’s no known practical
treatment for Johne’s disease,”
said Whitlock. “That’s the bad
thing.”
The disease is spread through
manure. The bacteria is ingested
and attaches itself within the
cattle’s intestinal tract As a result
of the infection, cattle do not
absorb feed. The nutrients, includ
ing energy and protein, are lost.
The animal’s intestine thickens
and they lose energy. Weight loss
and diarrhea occurs. And the dis
ease worsens, resulting in death.
There are tremendous economic
losses associated with Johne’s dis
ease. The work the New Bolton
Center has done in diagnosing and
helping producers rid the disease
from their herds may help save far
mers millions of dollars.
Senl questionnaires
Previously, the research team
sent questionnaires to more than
400 farmers in the state. The study
followed cows to slaughter, and, as
part of the study, the center exa
mined fecal and tissue samples.
Many farmers filled out the
questionnaire and returned it The
results were surprising.
Of the positive findings, many
of the farmers did not even know
they had Johne’s disease on their
farms, according to Whitlock.
“Cows with early Johne’s dis-
Dr. William Donawick, professor of surgaiy at
ton, recently performed surgery on a Holstein calf at the
center. It is belter for the mother and the newborn can to
undergo the trauma of birth at an animal hospital, which has
the proper facilities and medical care, than at the farm. The
difference Is that the conditions are much better here, he
said.
any other. The reason they are
doing less, according to Dona
wick, is because cattle prices are
Dr. Robert H. W Marilyn M. Simpson professor of
equine medicine at tha New Bolton Center, examines a cul
ture of Johne’s bacteria in the lab. According to Whitlock,
there Is often a source of frustration for the farmer or veter
inarian to quickly receive results of a test, because the bac
teria take so long togrow. “The research on the disease has
been aimed at trying to answer some of the questions about
Johne’s disease," said Whitlock.
ease don’t show any clinical
signs,” said Whitlock. “They
became infected when they woe
down “and that makes a difference
as far as the potential value of the
young animals.”
young calves, usually in the first
few weeks of life, and they don’t
show any clinical signs.”
Disease mistaken
The symptoms of Johne’s dis
ease, which include weight loss
and diarrhea, don’t appear until 2
to 10 years after the animal is bom.
The disease could have been mis
taken for general lameness or fai
lure to breed back, and could have
been “silent” on the farm for a
number of years.
The disease is transmitted
through the manure, which conta
minates the feed and the milk. The
calves ingest the contaminated
feces and the bacteria reside in the
‘Less than 25 per
cent of the farmers
in the state are
not aware that
their cows are
infected on their
farm,*
intestinal tract, where the organ
ism slowly multiplies.
The bacteria takes 3 to 4 months
to grow. According to Whitlock,
there is often a source of frustra
tion for the farmer or veterinarian
to quickly receive results, because
the bacteria take so long to grow.
“The research on the disease
has been aimed at trying to answer
some of the questions about
Johne’s disease,” said Whitlock,
including establishing the “gold
standard,” the fecal test, which is
the most reliable way of finding
out if an animal has been infected.
(Blood tests report too many false
positive results, according to
Whitlock.)
Not as sensitive
“The problem with the fecal
test,” said Whitlock, “is that it is
very specific but it’s not as sensi
tive." Whitlock said the sedimen
tation test detects “perhaps 10-15
percent” of the cows that are actu
ally infected.
“The test we currently have in
place here will detect three times
more cows that are infected,
approximately 40 to SO percent,’’
he said. “Our research will con
tinue to look at ways to improve
the sensitivity of fecal cutlure or
other tests to detect cows that are
infected but that we currently can
not detect.”
The highly sensitive test was
developed from work pioneered by
the Animal Disease Research Insi
tute in Ottowa, Canada. They
recommended to New Bolton Cen
ter that “we evaluate a centrifuga
tion technique, which concentrates
the organisms in the sample.
“So we did that,” Whitlock
said, "and found that it did
increase the sensitivity three times.
We’re currently evaluating other
ways to further increase the sensi
tivity of the culture test, up to 5 or
10 times compared to the standard
sedimentation test available
now.”
*Farmers need to
be encouraged to
get the calves out
of the barn , so
that there 9 s no
contact with the
adult cows ,
because it 9 s the
adult cows that are
shedding the
organism in the
manure , 9
Access to records
The center is working closely
with the Pennsylvania Department
of Agriculture in Summerdale,
Pennsylvania. The lab provided
the center with access to records on
farms that were tested positive for
the disease.
About 20 farms agreed to parti
cipate in a research project on
Johne’s disease using their herds
as part of the research. The
researchers use the information to
make recommendations on how
the farmers can reduce the preva
lance of Johne’s disease on their
farms, said Whitlock.
“The goal is to come up with a
set of recommendations that we
can provide to farmers in the state
if they have Johne’s disease, so
farmers can work toward a
certified-free status,’’ he said.
The major recommendations the
center has found to date is for far
mers to separate the newborn calf
as quickly as possible from the
dam.
Research indicates
that the bacteria
are present in the
infected cow’s
milk.
Calves out of barn
“Farmers need to be encour
aged to get the calves out of the
bam, so that there’s no contact
with the adult cows, because it’s
the adult cows that are shedding
the organism in the manure,” said
Whitlock.
(Turn to Pago A4l)