The Rural Voice, 1996-03, Page 31separate buildings on the farm sites.
The performance of these pigs was
measured against that of
contemporary pigs reared in
continuous -flow units on the
respective farms. In all cases, pigs
reared all -in, all-out had less
evidence of pneumonia and reached
market weight two to six weeks
sooner.
The Purdue researchers then
tested how much separation was
needed to achieve the
performance benefits. Pigs from a
herd with mycoplasmal pneumonia
were reared all -in, all-out through the
nursery. When they were eight weeks
old, some were moved to off-site
facilities while some were moved to
a separate building on the same site,
some to a walled off end of a large
finishing barn and some placed in a
continuous -flow finishing barn along
with other coughing pigs. The result
indicated that the better the
separation, the fewer pigs had lesions
from pneumonia at slaughter. Except
for the walled-off unit, the better the
separation the better the growth rate.
For disease prevention and
performance improvement, they
concluded, off-site separation was
better than separation by building,
which was better than separation by
room. Pigs in a continuous flow barn
had the most pneumonia and the
slowest growth.
In his talk on the nuts and bolts of
making SEW work, Clark told the
230 producers present (the largest
audience in the past three years) that
the key to the production method is
isolation of the pig from the three
sources of infection: the mother, the
environment and other pigs.
Research shows that while the
mother passes many diseases to her
piglets, she also provides immunity
in her colostrum for the first few days
of the pigs' life. After that immunity
wears off, however, the young pigs
can pick up the diseases from the
breeding herd.
By weaning, and isolating, the
pigs before 21 days, the researchers
found many of the common diseases
were missing and that some diseases
for which they carried the virus or
bacteria, did not develop.
But while early weaning gives the
pigs a head start in not having to
waste energy developing immunities
to infections, the environment helps
keep this edge to maturity.
Biosecurity is essential to making
SEW work and the system has failed
for some producers who haven't been
vigilant enough.
Nursery units should be far
enough from breeding units so that
It takes a lot of energy to fuel the
immune system.
you can't walk the distance, Clark
said. People should never go from
breeding units to nurseries. "You
have to stop all people movement
without being clean." People should
have clean clothing and clean hands
before entering a nursery. The system
had broken down for some of the big
integrated operators in North
Carolina and disease infected their
barns because they weren't attending
to the rules about preventing
transmission of disease.
In building new facilities, the
cleanest pigs should be the furthest
west on the same site to prevent
disease transmission. Nurseries
should be at Itast 100 yards west of
the sow herd. All facilities should be
all -in, all-out with the building or
room power -washed and disinfected
when a group moves out.
When multiple -aged pigs are in
a multiple room site, workers
should go from the highest
health pigs (usually the youngest) to
the oldest and not return unless they
shower and change clothing.
Even when transferring pigs from
the farrowing barn to the nursery unit
biosecurity must be carefully
attended to. The personnel who take
MARCH 1996 27
0