First and foremost, it is important to note that
the following information is in regard to feeding aflatoxin-contaminated
corn to beef cattle and does not have any validity for selling corn.
For interstate commerce, there are very strict guidelines with regard to
aflatoxin-contaminated corn.
Aflatoxin can result in a reduced appetite, reduced
growth or milk production, rough hair coat, immunosuppression as well as
many other possible symptoms. Depending on interactions with other
mycotoxins (realizing that when mold is present there are probably several
different mycotoxins being produced), aflatoxin concentrations as low as
100 parts per billion (ppb) may be toxic to beef cattle. However,
the toxic level is generally considered to be between 300 and 700 ppb.
A good rule of thumb would be to use 200 ppb as a target concentration
to stay below. Obviously, all people have differing ideas on degree
of risk, as an extension employee I would rather error on the side of caution.
The 200 ppb concentration is a number that would
be for the total diet; therefore, if you were supplementing brood cows
with 4 pounds of corn per day and they were consuming an additional 24
pounds of hay then the corn could actually contain as much as 1,400 ppb
aflatoxin and the cow�s total intake is still at the 200 ppb level.
However, be aware that some cows will get more than 4 pounds when group-feeding
and also you may get to high enough levels that the grain is actually unpalatable
to the cows and they won�t consume 4 pounds of it.
Various strategies for reducing the effects of the
aflatoxin include the following: ammoniation, blending with aflatoxin-free
grain, screening and addition of clays. Again, all of these strategies
are for on-farm feeding not for sale of corn. Ammoniation of the
grain with anhydrous ammonia at a rate of approximately 3/4 pound per bushel
of corn has been shown to destroy the aflatoxin. It is best to do
this with the corn on concrete and under plastic not in a grain bin.
Once the anhydrous has been put into the stack the process takes about
three weeks at which time the plastic is removed and remaining anhydrous
allowed to escape. CAUTION - Anhydrous ammonia is dangerous!
Blending with uncontaminated grain simply is a dilution technique.
Screening may be beneficial in that most of the aflatoxin is in the broken
kernels, tips and otherwise damaged pieces. Once the corn has been
screened it can be re-tested to see what the new aflatoxin level is, probably
reduced. Research has shown some benefit from incorporating small
quantities of clays (e.g., bentonite at .5%;10 pounds per ton) for binding
the aflatoxin so that it is carried on through the digestive tract and
into the manure rather than absorbed into the body. Does not always
work.
A key factor in all of this is that the analysis
is accurate, which starts with getting a good, representative sample of
the corn. Once the sample is obtained it will need to be sent to
a testing lab. Below you will find a list of some labs that can measure
aflatoxin as well as other mycotoxins. I am unfamiliar with their
costs. I�m sure there are many other labs as well, this just happens
to be the list that I have.
One in-state lab that I am aware of that will also
measure aflatoxin is the Peanut Inspection Service in Dothan, AL.
Their phone number is 334-792-5185.
A&A Laboratories Inc.
1000 Backus Ave.
Springdale, AR 72764
800-962-7120
A&L Analytical Labs
411 N. 3rd St.
Memphis, TN 38105
901-527-2780
Analab
18246 Waller Rd
Fulton, IL 61252
800-435-9560
Anitox Corp.
1055 Progress Circle
Lawrenceville, GA 30043
800-241-8357
Central Analytical Laboratories Inc.
101 Woodland Hwy
Belle Chasse LA 70037
504-393-5290
Diversified Laboratories Inc
3810 Concorde Parkway
Chantilly, VA 20151
703-222-8700
Woodson-Tenent Laboratories
1331 Union Ave, Suite 1500
Memphis, TN 38104
901-272-7511