A3B-Lancaster Farming, Saturday, December 8, 1990
Feed
GEORGE F.W. HAENLEIN
Extension Dairy Specialist
University of Delaware
When Aflatoxin-Containing
Feeds Are Fed
Alarming reports about farm
milk being condemned in several
areas of the United States have
come to my attention recently:
“Texas study finds aflatoxin worst
in 5 years; 40-60% of samples
exceed safe levels, some as high
as 2,000 ppb.” One pbb (part per
billion) is 1 microgram per 2.2 lb
grain, or one 28,350,000 th of an
oz. per 2.2 lb. grain.
Another trade journal reports
that producers with tests of less
than 20 ppb will be able to sell
their com at prevailing market
prices, while those with tests of
20-100 ppb will be docked 10
cents/bu. For levels in the 100-300
ppb range, there will be a discount
of 30-50 cents/bu. as much as
$18.5 million worth of com in one
state alone will not be marketable
at all, with the total loss predicted
at more than $3O million.
Even more disconcerting is
another recent study which shows
that aflatoxin and all the undesir
able molds in the mycotoxin fami
ly are not only a frequent problem
in Southern states, where it is
often warm and humid and ideal
for mold growth, but also a persis
tent concern in Midwestern states.
In Nebraska, Minnesota, lowa,
Illinois, Indiana, Michigan and
Ohio, the study found 1 in 4 sam
ples to have mycotoxin levels.
Not too many years ago here on
the Delmarva peninsula we also
experienced weather conditions
that produced detectable mycoto-
DAIRY FARMERS!!
COME TO ONE OF THE FOLLOWING MEETINGS
TO FIND OUT HOW YOU CAN HELP:
Toxicity Reviewed
xin levels on corn. And com is not
the only crop affected. Peanuts
have long been a problem,
depending on the kind of storage,
as has cottonseed. Though greatly
underestimated, our com silage on
the peninsula, especially in the big
horizontal bunkers, often has a lot
of mold growth on the surface as
secondary invasion following
opening and improper loosening
of the silage’s surface. Few people
have a thorough appreciation of
the hidden menace these molds
carry for farm animals and people.
Symptoms of aflatoxicosis are
several, depending on the level;
abortion, repeat breeding, drop in
milk production, reduced feed
intake, nasal discharge and runny
eyes, scours, mastitis, unthrifty
calves and even death. Adult cattle
may recover in many cases, but
calves can be affected longer.
It is difficult to guess which
grains or feeds have mycotoxin
levels. Unlike the non-toxic, even
beneficial, green or white molds
that we know from penicillium,
for example, or from Camembert
or Danish blue cheeses, the myco
toxin molds generally require so
called blacklight testing or chemi
cal analyses in a specially
equipped laboratory. And not all
levels are seriously bad. For lac
tating cows (and dairy goats prob
ably, too) a safe level in the daily
ration must be less than 20 ppb.
For yearling heifers the safe level
may be up to 100 ppb. Prolonged
feeding will be a problem.
Recent guidelines from the Uni
versity of Georgia indicate that
corn with mycotoxin levels to
some extent can, for instance, be
WE WANT TO IMPROVE YOUR INCOME
DON’T WAIT UNTIL ITS TOO LATE!
THURSDAY. DECEMBER 13
1:00 PM
7:00 PM HONEYBROOK GRANGE
join Ni now
HOFFMAN COMMUNITY
QUARRYVILLE, PA
RT 10 SOUTH
HONEYBROOK, PA
used. When aflatoxin levels
exceed 200 ppb, serious consider
ation should be given to ammonia
treatment of the com in order to
detoxify aflatoxin. Estimated cost
for treatment with ammonia,
anhydrous or aqua ammonia a few
years ago was 12-15 cents/bu to
reduce aflatoxin levels to where it
can be fed. Georgia Extension
Bulletin #869 gives details.
Ammoniated com will be golden
to dark brown in color and will be
eaten readily by dairy cattle.
Safe levels of feeding can be
calculated by changing propor
tions of safe and unsafe grains in a
concentrate mixture. Com with
100 ppb aflatoxin mixed at 800 lb/
ton with concentrates will test
only 40 ppb, bringing it down to
the maximum allowable level of
20 ppb, if the concentrates make
up no more than 50% of the daily
dry matter feed intake of dairy
cattle, and that safe hay and silage
make up the other 50%.
For 80 ppb aflatoxin com, 1000
lb could be used in a concentrate
mixture resulting in 40 ppb, and
still giving only 20 ppb safe levels
when intake remains 50%. If cows
are eating 20 lb of that concentrate
mix and 25 lb of dry matter from
silage and hay for a total of 45 lb
daily intake, then the cows would
be getting 20 lb times 40 ppb
divided by 45 lb for a total of 17.7
ppb in the entire ration per day.
However, if the same cow ate 25
lb of that concentrate mix, then
she would increase her daily
intake up to 22.2 ppb. If you want
to feed com with a 500 ppb level
for a short time to heifers, for
example, at a level of 100 ppb.
then 100 ppb divided by 500 ppb
results in a 20% limit of such com
to be used in a total ration.
Other strategies include specif
ic silicate salts of calcium, sodium
and aluminum that can reduce
aflatoxin effects by binding and
excreting in the feces after they
have been mixed with the concen
trates at 1% (20 Ib/ton) and con
sumed at 0.2 Ib/cow/day. The
costs may be around $B/ton.
Now that corn has been
harvested, close attention must be
given to correct bin management
Air must be circulated to keep
moisture below the magic 12%,
the point at which molds love to
grow. When outside air tempera
tures are 10 degrees Fahrenheit or
more below grain temperature,
then air again must be circulated
until temperatures are closer
Ag Offices
Move To
New Location
SUNBURY (Northumberland
Co.) The offices of the North
umberland County Conservation
District, USDA Soil Conservation
Service, and the USDA Agricultur
al Stabilization and Conservation
Service recently moved to a new
location.
The three offices moved from
their old location on Route 61 to
new facilities on Plum Creek Road,
RD 3, Sunbury. Plum Creek Road
is located just off Route 890, 1.1
miles south of the Route 61-Route
890 intersection. The new office is
0.7 mles east of the Route
890-Plum Creek Road
intersection.
The new mailing address for all
three agencies is RD 3, Box 238-C,
Sunbury, PA 17801. Phone num
bers have not changed.
BUILDING
HALL
together. Humidity must be held
below 65% to prevent moisture
addition to the grain. Aeration
should not be used when grain
temperatures are below outside
temperatures. Again, a Georgia
Extension Bulletin (#712) gives
details.
If you suspect mycotoxins in
your feeds including silages this
fall and winter, don’t panic. Have
the feeds tested in a reliable lab
before you feed them, and adjust
your ration intake per cow and
heifer below the unsafe levels to
protect the health and reproduc
tive efficiency of your animals.
This will ensure their profitabilit>
for you as well as produce safe
milk for human consumption,
because certain molds are found
as metabolites in milk.
Farmland Saved
HARRISBURG (Dauphin Co.)
The Pennsylvania Agricultural
Land Preservation Board last
week approved a plan to save
prime farmland in Franklin Coun
ty and authorized the purchase of
easement rights on a Chester
County farm.
The board approved an ease
ment purchase for the Janet and
David Mast farm in Chester Coun
ty, bringing to 21 the number of
farms preserved under the state
program. Another four farms in
Lancaster County and one in
Chester County were protected
through easements purchased
exclusively with county funding.
Located in West Nantmeal
Township, the 109-acre Mast fam
ily farm produces wheat, com and
soybeans.
Pennsylvania now has 2,082
acres of prime farmland perma
nently protected from develop
ment.
1990