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Vomitoxin and Zearalenone Distribution
"From a Testing Lab Perspective"

Author:

Dale Cowan- Agri-Food Laboratories/Guelph
Albert Tenuta - Field Crop Plant Pathologist/OMAFRA Ridgetown
Creation Date: 07 November 2006
Last Reviewed: 07 November 2006

Table 2 compares the % distribution of mycotoxins (vomitoxin and zearalenone) for the two previous growing seasons (2004 and 2005) versus the initial results for 2006. In 2006 a major shift has occurred in samples that are testing greater then 6 ppm vomitoxin (9.6%) as compared to 0 % in 2005 and 0.4% in 2004. In addition, samples with 4-6 ppm vomitoxin (5.8%) have also increased this year when compared to 2005 (0%) and 2004 (1.8%). Although this is concerning the majority of the samples 62.6% analyzed to date were less than 1 ppm and 81.8% were 2 ppm vomitoxin or less. In comparison, on average 77.3% of the samples in 2005 and 2004 were less than 1 ppm and 92.65% of the samples in 2005 and 2004 were 2 ppm or less for vomitoxin. Ontario corn always has a certain percentage testing 1-2 ppm but these years numbers of 19.2% are slightly higher then the 15.4% two year average for 2005 (20.5%) and 2004 (10.2%).

CAUTION: We are still early in the corn harvest in 2006 compared to other years. Sample numbers represented in this 2006 summary are from 110 samples which are much lower then the final harvest sample numbers from 2005 (total 658 of samples) and 2004 (total of 274 samples). These 2006 vomitoxin numbers do further indicate an increase in vomitoxin (DON) levels for 2006. However, it will not be till the second week of November when a relatively larger sample number will be processed or when the final harvest numbers are completed in December.

Table 2. % Distribution of Vomitoxin and Zearalenone since 2004 in Ontario Corn submitted to Agri-Food Laboratories as of Oct 26, 2006
Vomitoxin ppm 2006
% 		2005
% 		2004
%
>6 9.6 0
0.4
4-6 5.8 0 1.8
2-4 3.8 7.4
5.1
1-2 19.2 20.5 10.2
0.2-1 44.3 51.5 27
<.20 17.3 20.6 55.5

 

Zearalenone ppm 2006
% 		2005
% 		2004
%
>0.4 5.9 14.3 4.4
0.2-0.4 11.8 21.4 0
0.1-0.2
23.5		 14.3 2.3
0.05-0.10 17.6 0 0
<0.05 41.2 50 93.3

 

The following summary table 3 describes some important mycotoxins commonly found in Ontario, generally accepted tolerances, and effects of these toxins on swine (Source Jaydee Smith, Swine Specialist, OMAFRA, Ridgetown)

Table 3. Maximum concentrations for various mycotoxins in swine feed rations*.
Mycotoxin
 Maximum Concentrations in Feed Comments
Vomitoxin (DON) < 0.5 ppm for young growing pigs and prepubertal gilts


 Reduction in feed consumption and weight gain are inversely proportional to concentration of DON. High concentrations cause feed refusal and vomiting. Even low levels can affect the immune system.
Vomitoxin (DON) < 1.0 ppm for breeding herd
Vomitoxin (DON) < 1.0 ppm for finishing pigs boars
Zearalenone
(ZEN)		 < 0.5 ppm for young growing pigs and prepubertal gilts

Estrogenic effects. Swollen vulvas, vaginal or rectal prolapses in pre-pubertal gilts. Enlarged uterus, swollen or twisted uterus, shrunken ovaries, abortion or stillborns, failure or delay in showing heat. In boars, testes atrophy, enlarged mammary glands, decreased fertility.

Usually less common than DON, but if conditions are right can be the more important challenge, and is especially dangerous to humans.

 
Zearalenone
(ZEN)		 < 0.5 ppm for breeding herd
Zearalenone
(ZEN)		 < 2.0 ppm for finishing pigs and boars
T-2 Toxin < 1.0 ppm Potent immunosuppressive agent that directly affects immune cells and modifies immune response as a consequence of other tissue damage. Frequent defecation, vomiting, weight loss and feed refusal. Complete feed refusal may occur at 16-20 ppm.


* Effects may depend on the presence of other toxins. Mycotoxins can interact, producing effects at levels lower than expected. These levels should be adjusted downward if feed intake is reduced or other obvious signs of toxicity are observed.

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