D2-Lancaster Farming Saturday, May 26,1990
Pork Prose
*? •
j Penn State Extension Swine Specialist
Dr. Kenneth B. Kephart
Extension Swine Specialist
Pennsylvania State University
Swine producers sometimes
have the choice of more than one
drug in the same category. For
example oxytetracycline and
chlortetracycline.
Sulfamethazine and sulfathia
zole. Lutalyse (which contains
prostaglandin) and Bovilene
(recently approved for swine,
which contains a prostaglandin
analogue). Which drug, within a
category, is the best choice or
doesn’t it matter?
OXYTETRACYCLINE VS.
CHLORTETRACYCLINE
When you look at the chemical
structure of these two drugs, it’s
hard to see the difference at first
glance. Chlortetracycline has a
chloride group (-C1) attached to
one part of the molecule. Oxytet
racycline has no chloride, but
instead has a hydroxyl group
(-OH) attached to Afferent part of
the molecule. Other than that, the
two drugs are identical.
Feed grade chlortetracycline
can be purchased under various
trade names, including Aureomy
cin and CTC. Trade names for
oyxtetracycline include Tcrramy
cin, TM, Oxytetracycline, and
Oxy tet. Both drugs can be added to
the feed or water (provided they’re
in the correct form). Injectable
forms are always oxytetracycline.
Do the two drugs act any diffe
rendy in the pig? American Cyana
mid Company (which produces
Aureomycin) recently sent some
swine producers results of a trial in
which pigs were medicated
through the water with either
chlortetracycline or oxytetracy
cline. Their data showed higher
levels of chorletracyclinc in the
blood and the lungs compared to
that of oxytetracycline. ,
Other research demonstrates
that adding the two drugs to the
feed also results in higher blood
levels of chortetracychne than
oxytetracycline whether added
at the rate of 200, 400, or 800
grams per ton. So from the stand
point of blood concentrations, and
perhaps levels in the lungs, chlor
tetracycline seems to have the
edge.
But oxytetracycline has a poten
tial advantage when administered
in the water, although both are
approved at similar levels. (Chlor
tetracycline can be added to water
at the rate of 200 mg/gallon.
Oxytetracycline can be added at
the rate of 200 to 400 mg/gallon.)
Data from several studies show
that oxy tetracycline is stable over a
wide range of pH when adminis
tered in water. From pH 2 to 5,
chlortetracytline is also stable. But
at pH 5, chortetracycline begins to
lose its stability, with only 80 per
cent of the drug remaining intact at
oH 6, and roughly half of the drug
n pH 8. (Most well water from
■ me soils will have a pH of at
least 7.)
Chortetracycline is also bound
more readily by calcium in the
diet A recent trial at South Dakota
State University showed that
changing from a low-calcium (0.6
by
Kenneth B. Kephart
percent Ca) to a high-calcium (0.9
percent Ca) diet caused blood
levels of chlortetracycline to fall
from 0.230 to 0.095 ug/ml a
drop of nearly 60 percent.
Under the same conditions,
oxytetracycline fell from 0.117 to
0.092 ug/ml a 21 percent drop.
But you’ll notice that even though
chortetracycline fell to a greater
extent, the absolute levels of chlor
tetracycline were still higher
(0.095 ug/ml) than that of oxytet
racycline (0.092 ug/ml).
What does all of this mean in
terms of treating disease in pigs?
It’s clear that both drugs are effec
tive. Literally dozens of trials have
proved that. But if you make a
side-by-side comparison of oxy tet
racycline and chlortetracycline,
which drug boosts hog perfor
mance the most?
I asked the same question, in a
recent computer library search
covering the last 20 years of pub
lished studies. I couldn’t find a
single report that made this com
parison with pigs. Until we get that
data, there is little justification for
choosing one over the other.
SULFAMETHAZINE VS.
SULFATHIAZOLE
Hog producers have a number of
sulfas at their disposal. The two
most widely used forms have tradi
tionally been sulfamethazine
(included in ASP-250 and Tylan
plus Sulfa) and sulfathiazole
(included in CSP-250).
Sulfamethazine has been under
fire in recent years because of
residue problems in pork, veal, and
even milk. According to the Food
Safety Inspection Service (FSIS),
nearly all of the sulfa residue viola
tions in pork between 1983 and
1986 occurred with sulfametha
zine. During this four-year period,
violative levels of sulfamethazine
were found in 4 to 6 percent of the
tissues sampled. In those same
samples, not a single violation of
sulfathiazole was detected. Why?
Reportedly, sulfamethazine is
absorbed and retained in both
blood and tissues at higher levels
than that of sulfathiazole.
That, according to some indivi
duals* makes sulfamethazine a bet
ter drug. But many studies dispute
that claim. A report from the Uni
versity of Tennessee (1982)
showed that CSP-250 was equal to
ASP-250 in controlling Bordatella
Bronchiseptica infections (atroph
ic rhinitis). A study by American
Cyanamid (1984) showed
CSP-250 gave slightly belter con
trol of the same disease compared
to that of ASP-250. And a report
just released by Fermenta demon
strated that CSP-250 and ASP-250
both improved weight gain and
feed efficiency to the same extent
in pigs infected with Bordatella
and Pasteurella. The number of
positive nasal swabs (for both Bor
datella and Pasteurella) was lower
in the CSP-250 group.
So there is little logic for using
sulfamethazine. For whatever rea
sons, its use has created more vio
lative residues than all the other
sulfas combined. And its effective
ness in controlling disease and
improving performance appears to
New Egg Regs Affect
COLLEGE PARK, Md.
Since 1969, Maryland honey pro
ducers have had to comply with a
registration program for their bee
colonies to help control the spread
of American foulbrood and other
bee maladies.
In a similar vein, the state’s egg
producers are now being asked to
comply with a registration prog
ram for their poultry flocks. The
new rules and regulations became
effective in April. Large commer
cial producers already are comply
ing; but operators with small,
backyard flocks may not be aware
of recent modifications to the
1957 Maryland Egg Law.
For that reason, information
leaflets and registration applica
tions are being made available at
county offices of the University of
Maryland Cooperative Extension
Service. Compliance enforcement
is a joint effort of the Maryland
Department of Agriculture and the
state Department of Health and
Mental Hygiene.
Dr. John A. Doerr, acting chair
person for poultry science on the
University of Maryland campus at
College Park, notes that the new
rules have a twofold purpose:
Grange Supports Farm
Product Damage Bill
HARRISBURG (Dauphin Co.)
The incident of crop damage
caused by wildlife, especially the
growing population of deer in rur
al Pennsylvania, is potentially
devastating to fanners.
The Pennsylvania State Grange,
which represents 42,000 rural
Pennsylvanians, is greatly con
cerned with the recurring crop loss
that fanners must face.
The Grange supports SB 647,
which allows farmers to obtain a
farm product damage control per
mit. That permit would give a far
mer the ability to have people not
associated with the farm help con
trol the wildlife between August
and October. Currently only far
mers, their families, and hired
help are permitted to eliminate
damaging wildlife.
“Giving the farmers this addi
tional help with the task of saving
their crops until the harvest is over
is an important measure,’’ said
Brenda Shambaugh, Pennsylvania
State Grange legislative director.
“Farmers can lose a substantial
amount of income by these ani
mals, which destroy crops by eat
ing and trampling.”
The bill would require that far
mers have at least $5OO of crop
damage to qualify for the permit
It would also require that a game
officer be notified when shooting
is planned. In addition, the proper
ty for which the permit is sought
must have been accessible by the
public for hunting during the cur
rent or previous year.
be the same as that of
sulfathiazole.
LUTALYSE VS.
BOVILENE VS.
ESTRUMATE
Though the names wouldn’t
give you a clue, all these products
contain similar compounds.
Lutalyse (produced by Upjohn)
contains prostaglandin F-2 alpha.
About 7 years ago it was approved
for the purpose of inducing farrow
ing in sows. This is the same com
pound involved in the natural onset
of parturition.
(Turn to Pago D 4)
• To instill consumer confi
dence that Maryland eggs are
wholesome and safe.
• To provide a mechanism for
tracking down sources of contami
nation and helping affected pro
ducers clear up potential disease
problems at an early stage.
Doerr explains that the regula
tions apply to any person who
sells eggs—whether one or a mil
lion to retail outlets, distribu
tors, restaurants, or directly to
consumers. A three-step proce
dure is required. It involves
registration, carbon imprinting,
and maintenance of invoices or
sales slips.
Registration forms must be sent
to the Maryland Department of
Agriculture in Annapolis. They
are available from county exten
sion offices throughout the state,
along with a brochure explaining
the new egg law requirements.
Upon receipt of the completed
application form, MDA officials
will issue a registration number.
This number must be printed on
all egg cartons sold.
In addition to the registration
number, cartons must be identi
fied as containing eggs; they must
be imprinted with the seller’s
David Kradel Herbert Jordan Milton Madison
BIRD COMFORT
DURING HOT WEATHER
Forest Muir
Professor of Poultry Science
A properly serviced and oper
ated ventilation system is impor
tant for maintaining bird comfort
during hot weather.
Bird comfort is one of the keys
to efficient productivity. The three
components of the ventilation sys
tem which must be serviced for
summer conditions are the inlets,
fans, and controls.
The inlets are the entry point of
fresh air into the poultry house. Air
inlet openings should be covered
with screening of a size that will
prevent wild birds from entering
the building. This screening will
catch dust, feathers, and other
debris.
This material will not normally
fall away from the screening but
only serve as an obstruction to
entrap additional material. Suffi
cient air flow can enter the poultry
building through dusty inlets to
maintain desired temperatures dur
ing spring conditions. However, a
proper building environment can
not be maintained during hot
weather with dirty inlets. The inlet
screening should be cleaned and
maintained dust-free to allow max
imum air flow when needed.
Fans are the heart of the ventila
tion system. Establish a schedule
for servicing the fans. The servic
ing schedule should be more fre
quent during the summer months.
Proper fan maintenance includes:
• Checking to make certain all
fans are operational and have been
lubricated, if required.
Producers
name and address, lot number, or
date eggs were packed; number of
eggs in the carton; and grade and
size of eggs, along with instruc
tions to keep eggs refrigerated.
A sales slip or invoice must be
provided, and copies retained for
at least 90 days. The invoice must
include name and address of both
buyer and seller, date of delivery,
grade and size of eggs, lot number
or date of packing, and seller’s
registration number. These last
two items may be included on a
packing slip inside the case,
instead of on the invoice.
Dr. Charles J. Wabeck, poultry
products specialist at Princess
Anne for the University of Mary
land Cooperative Extension Ser
vice, commented about the new
regulations:
• If you purchase eggs for
resale, get a copy of the produc
er’s Maryland registration or plant
number.
• When buying layer flock
replacements, be sure to request a
Pullorum-Typhoid clean flock
certificate from the breeder.
Your Maryland Cooperative
Extension Service agricultural
agent can provide assistance in
filling out the registration form,
imprinting egg cartons, and pre
paring sales slips or invoices. The
Maryland Department of Agricul
ture also stands ready to assist egg
producers.
Morris Mast
• Cleaning the fan blades, ori
fices, and motors.
• Cleaning and lubricating
(using graphite) the fan louvers.
• Adjusting belt tension and
replacing belts when necessary.
• Stocking spare replacement
fan belts.
Proper fan maintenance can
increase the air delivery capacity
of a fan by as much as 30-40
percent.
Dust should be reproved from
the sensing units of thermostats.
Dust on sensing units can act as an
insulating agent and reduce ther
mostat sensitivity.
Most poultry air inlet systems
are regulated by automatic inlet
controllers. These controllers use a
manometer as the sensing device.
The manometer in these units
should be serviced. This includes
checking the fluid level and cali
brating the zero setting.
Adjust the automatic inlet con
troller to maintain a 0.04-0.06 sta
tic pressure in the building. A sta
tic pressure of 0.04-0.06 inches of
water translates to an air speed of
800-1,000 feet per minute at the
inlet
Increasing the static pressure
will increase the air speed at the
inlet but will not necessarily
increase the amount of air ottering
the building. In fact, increasing the
static pressure may actually
decrease the quantity of air enter
ing the building. The increase in
static pressure causes the fans to
work harder and can reduce the
amount of air that they move. An
increasein air speed at the inlet can
also change distribution patterns in
the building and actually create hot
spots.
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