The Rural Voice, 1999-03, Page 36The best of
both worlds
Dr. Tim Blackwell says
farmers can sooth
consumer worries about
antibiotic drug residues
at very little cost
By Keith Roulston
As pressure mounts on farmers
over the use of antibiotics in
feeds, good pork producers
could help the situation with little
cost to themselves by withdrawing
drugs for the last 60 days before hogs
go to market, Dr. Tim Blackwell told
the Centralia Swine Research Update
in Kirkton, January 27.
"Half the farms in Ontario don't
need to feed antibiotics for the last 60
days," he said. If pigs are healthy the
gain in feed conversion at that time
of their life is small. It may add $1.50
in feed costs but you'll save $1.50 in
drug additive costs, he said.
But, he said, 85 per cent of
producers use feed drugs up to
slaughter.
"If we could say for the last two
months the pigs don't get any drugs
unless they're sick it might look
better on us," said Blackwell on the
same day the United States
announced tougher regulations on
use of antibiotics in animal feeds.
Canada, outside of Quebec, has
the most liberal policy regarding
animal medicines in North America
and Europe. There is an "amazing
difference" between our policy and
the U.S. even before the latest
changes.
The ' agriculture industry, in
denying there is proof of any link
between antibiotics fed to animals
and anti -biotic resistant bacteria have
been carrying out the same kind of
32 THE RURAL VOICE
game the tobacco industry did for 40
years when it denied there was any
sound scientific link between
smoking and early death, Blackwell
said. "Nobody's proved it? That's
garbage."
If there are antibiotics used there
will be antibiotic-resistant bacteria,
he said. There are always survivors
of every killer, he said. Some trees
withstood Dutch elm disease. The
difference is that bacteria reproduce
every 15 minutes and can adapt
faster.
The point isn't whether bacteria
do adapt, but whether those resistant
bacteria make people sick, he argued.
Some of the drugs used on animals
are also used in human medicine.
Some of the drug-resistant bacteria
can cause disease in people and the
illnesses from these "farm -grown"
bacteria are more difficult to treat.
One of the infections of greatest
concern is Salmonella.
Use of antibiotics in feeds has
been growing since, 50 years ago,
researchers found that chickens fed
low levels of antibiotics grew faster
and required less feed. No one has
entirely understood why antibiotics
work this way but many new
antimicrobial agents have been
developed in the years since which
have -had the same positive effects on
feed efficiency and average daily
gain.
Half the antibiotics produced in
the U.S. are fed to animals but 90 per
cent of the profits for the drug
companies come from selling to
humans because they get a lot more
from a capsule than from the drugs
farmers feed to their animals.
Levels of antibiotics in animal
feeds are very low. Even if a
producer adds a kilogram of Tylan 10
to a tonne of feed, he is actually only
adding 22 g of the active ingredient
(tylocine) with the other 978 g being
simple cornstarch or some other
carrier which helps the drug to be
mixed evenly through the large
volume of feed.
Balanced against that is the good
the drugs do in terms of animal
welfare, more efficient growth, and
environmental protection, Blackwell
says. Because animals are healthier,
they suffer less. Because they convert
more efficiently, they not only
produce food at lower prices, but
they create less manure in doing so.
But the major benefit from
medicated feeds is to the younger,
sicker pig, Blackwell says. The older
and healthier the pig, the less
response there is to low-level doses
contained in feeds. In nursery -aged
pigs, the improvement in feed
efficiency through such growth
promotants is four to six per cent,
and even higher if it helps prevent
scours. In finishing barns the average
improvement is only two to four per
cent.