Deoxynivalenol Occurrence in Cereals and Complete Feed Worldwide

1. Global Deoxynivalenol Occurrence

Fusarium toxins were the most frequently occurring mycotoxins globally over the past ten years [1]. Deoxynivalenol (DON) is the most common mycotoxin and a highly toxic type B trichothecene, which is a naturally occurring metabolite of fungi from Fusarium graminearum and Fusarium culmorum that may contaminate feedstuffs used in feed formulation [2,3]. Among feedstuffs that were positive for DON, corn and wheat were the most frequently contaminated [4]. In maize distiller’s dried grains with soluble (DDGS), DON showed a higher prevalence (83% of positive samples) and a higher median value (1,490 μg/kg) than in any other commodity [1]. Similar to maize DDGS, maize silage, wheat, and barley showed that DON was the most prevalent mycotoxin in these feed ingredients (62%, 65%, and 61%, respectively) [1].

In the past (from 2008 to 2017), the most DON-contaminated regions in the world were East Asia, Northern Europe, and Central America, with 84.8%, 74.2%, and 70% of the positive rate [1]. Due to global climate change, many regions experience unusual droughts, heavy rains, or abnormal temperatures (extreme hot or cold); hence the areas with the highest DON contamination have changed slightly. The newest 2022 study [5] indicated the most contaminated regions for DON were China and Taiwan, Middle East and North Africa, and South Africa, at 84%, 81%, and 77% of their feed ingredients and animal feed, respectively. It should be noted that East Asia (including China and Taiwan) has been a high-contamination area for DON from then to now. Rainfall and mild temperatures during the flowering and maturation periods were shown to favor the infestation of wheat and maize with Fusarium spp. contamination and DON production, and these climate conditions are consistent with the situation in East Asia [1,6]. 

Table 1. Regions with the top three highest occurrence of deoxynivalenol in the grain and balanced feed in the global investigations (organized data from [1,5])

2. Asia

2.1 East Asia

Deoxynivalenol occurrence performed along the same lines as zearalenone (ZEN) occurrence in East Asia, with DON being more prevalent (84.8% of positive samples) in East Asian raw materials and finished feed than in samples from any other region [1]. East Asia is the most contaminated region in the world with DON and ZEN, with a relatively high median concentration of 418 μg/kg detected for DON. In total, 20.6% and 0.7% of crop and compound feed exceeded the lowest (900 μg/kg) and the highest EU guidance values (8,000 μg/kg) for DON, respectively [7]. Deoxynivalenol levels of corn were low in 2013 relative to other years in this region, which may reflect the relatively lower levels of rainfall in August and September (leading up to harvest) that year in the core Chinese maize growing areas compared to the following years [1]. In the 2022 global survey [5], DON occurrence was independently calculated in China and Taiwan at 84%, which is the highest prevalence, and the rest of the countries of East Asia still had the higher occurrence (73%) of the same mycotoxin around the world. East Asia demonstrated the highest levels of DON and ZEN contamination, and these two mycotoxins have the most severe effects on porcine growth performances and reproductive abilities; hence, pig farmers and the feed industry should pay more attention to tracking and controlling DON levels in local feed ingredients and swine feed.  

2.2 South Asia

Compared to other regions, South Asia was one of the few areas where DON was not one of the top three prevalent mycotoxins, and this toxin had a 23.1% positive rate in cereal and complete feed with 96 μg/kg from 2008 to 2017 [1]. It should be noted that DON occurrence was not only the lowest, the median level was, but also the second lowest compared to the rest of the regions of the world. Due to the hot climate conditions, in 2022 [5], DON was still not one of the top three most contaminated mycotoxins because aflatoxin (AF, 85%), ochratoxin A (OTA, 77%), and T-2 toxin (T-2, 72%) contaminations were more severe than DON in the feed ingredients and compound feed from South Asia. However, in recent years, DON occurrence has risen sharply to 33% because of global climate change, and the ZEN positive rate also significantly increased at the same time; hence, the local livestock industry not only needs to track ALF, OTA and T-2 but also need to notice DON and ZEN in cereal and complete feed. 

2.3 Southeast Asia

Similar to South Asia, Southeast Asia was one of the few areas where DON is not among the top prevalent mycotoxin. Approximately 42.5% of raw materials and finished feed were contaminated with DON at a median concentration of 137 μg/kg [1]. In 2022 [5], DON was not more prevalent as other mycotoxins in Southeast Asia as of old. However, in contrast to the increase seen in South Asia, DON positive rate had significantly decreased to 32% in this region.

2.4 Central Asia

According to the previous data (from 2008 to 2017) [1], DON was the most frequently occurring mycotoxin in the cereal and animal feed of Central Asia, with a positive rate and median concentration of 26.7% and 28 μg/kg, respectively. However, the median value of DON in grains and complete feed in this region was the lowest level among all regions in the world. The newest survey [5] mentioned that DON still was the most prevalent mycotoxin (14%) in this area, tied with ZEN (14%).

3. Europe

3.1 Eastern Europe

 From 2008 to 2017 [1], DON and another highly toxic Type A trichothecene T-2 were the most prevalent mycotoxins (59.9% and 48.2% of positive rates, respectively), and their median levels were 153 μg/kg and 21 μg/kg respectively in cereal and balanced feed collected from Eastern Europe. A 2022 global survey [5] indicated that DON positive rate dramatically dropped to only 39% compared to past records because of climate change, consequently, DON was surpassed by ZEN (48%) and T-2 (44%), it became the third most prevalent mycotoxin in this region.

3.2 Northern Europe

Similar to Eastern Europe, trichothecenes were the most prevalent mycotoxins in cereal and complete feed from Northern Europe, with 74.2% and 30.3% of DON and T-2 prevalence, respectively [1]. It should be noted that Northern European grain and balanced feed not only had the second-highest occurrence of DON but also had the second-highest median concentration of 504 μg/kg than in samples from any other region around the world from 2008 to 2017. Besides, 21.5% of grain and finished feed did not comply with the lowest EU guidance value for DON. Although in recent years, DON still was the most prevalent mycotoxin in raw materials and animal feed in this area, the positive rate has significantly decreased to 63%, 51%, and 52% in 2020, 2021, and 2022, respectively [5,8,9]. 

3.3 Central Europe

Deoxynivalenol was the most prevalent mycotoxin (69.8%) in cereal and complete feed samples from Central Europe in the investigation during the period from 2008 to 2017 [1]. It’s worth noting that DON reached the third-highest median level of 428 μg/kg compared to other regions, and it exceeded the lowest EU guidance values by 20.4% of raw materials and animal feed. In maize, the mean concentration of DON was significantly higher in 2014 than in the other years due to climate change. By 2022, the DON occurrence rate was maintained at 60% and the positive rate was still ranked one in cereal and animal feed [5].

3.4 Southern Europe

Deoxynivalenol was the second most prevalent mycotoxin in feed ingredients and animal feed in Southern Europe at a positive rate of 52.9% and a median concentration of 324 μg/kg from 2008 to 2017 [1]. As in Central Europe, the mean concentration of DON in maize peaked in 2014 because of heavier than usual rainfall that year. In 2022 [5], the positive rate of DON significantly decreased to 28% compared to those from 2008 to 2017. It should be noted that high levels of DON have been found mainly in oat grain from Nordic countries, while in Southern Europe, the highest levels have been found in wheat and maize [10]. For instance, DON occurrence and maximal concentration reached extreme records with 56% and 3460 μg/kg in the wheat from France in 2022 [5].

4. America

4.1 North America

Fusarium mycotoxins DON, FUM, and ZEN were the most prevalent in grain and balanced feed samples from North America, detected as 64.1%, 47.7%, and 31.7% of the positive rate, respectively [1]. Deoxynivalenol showed the highest median concentrations of 505 μg/kg compared to the other regions, and 19.1% of the samples exceeded the lowest EU guidance value. In both 2021 and 2022 [5,9], the DON prevalence in grains and balanced feed was 69% which was not substantially different from the previous investigation. In North American corn for 2022, FUM (71%) and DON (68%) were most prevalent, and the average concentrations of positives samples of FUM (2,488 μg/kg) and DON (1,155 μg/kg) increased compared to the past two years. An investigation for 2022 pointed out that extreme maximum levels were detected for FUM (45,785 μg/kg) and DON (17,673 μg/kg) in the maize from the United States. Not only corn, but American wheat also contained a high occurrence (94%) and a maximum concentration (1,330 μg/kg) for DON, respectively. 

4.2 Central America

In raw materials and finished feed samples from Central America, DON was the second most prevalent (70%) mycotoxin at the median concentration of 316 μg/kg from 2008 to 2017 [1]. It should be noted that Central America was the third-highest DON occurrence region worldwide during this period. In the DSM'S global survey for 2021 and 2022 [5,9], DON was still the second most prevalent mycotoxin in grain and balanced feed from this region; however, the positive rate had dropped to 64% and 56%, respectively. Unlike the DSM's 2021 and 2022 studies, Ventanco's 2021 survey [11] mentioned that DON was the third most prevalent mycotoxin in Central America. Its positive rate was only 49.7% at the average value of 745 μg/kg in feed ingredients and animal feed.

4.3 South America 

The previous survey indicated that DON was the third most prevalent mycotoxin after FUM and ZEN in South America [1]. The positive rate and median values of DON were 26.9% and 344 μg/kg for feed ingredients and animal feed from 2008 to 2017, respectively. Another investigation pointed out that South American wheat samples presented an average of 1.5 g/g of DON, representing a high risk for animal production, especially swine [12]. Deoxynivalenol occurrence significantly increased to 57%, 43%, and 41% in South American feed ingredients and animal feed in 2020, 2021, and 2022, respectively [5,8,9]. Vetanco survey for 2021 [11] mentioned different results that DON prevalence was only 27.9% positive rate at 834 μg/kg of average concentration in South American cereal and complete feed. It is worth noting that the same investigation indicated that the average DON value of raw materials and complete feed from Bolivia (1,875 μg/kg) and Peru (1,107 μg/kg) exceeded the lowest guidance value of the EU. Besides, a survey for 2022 [5] stated that extreme maximum levels were detected for DON in Argentine corn (16000 μg/kg) and Brazilian soybean (1,180 μg/kg), respectively.

Table 2. Occurrence and concentration of deoxynivalenol (DON) in Latin America (organized from [11]) 

5. Africa

5.1 Middle East and North Africa

In feed ingredients and animal feed from the Middle East and North Africa, Fusarium mycotoxins FUM, DON, and ZEN were the most frequently detected mycotoxins with 66.8%, 47.8%, and 44.8% positive samples, respectively [1]. However, due to global climate change, Fusarium mycotoxins are highly abundant, and the prevalence of ZEN and FUM, especially DON and T-2 toxin (T-2), have substantially increased in recent years. Deoxynivalenol occurrence dramatically rose to 78%, 55%, and 87% in 2020, 2021, and 2022, respectively [5,8,9]. The Middle East and North Africa leapfrogged to become the second area around the world with the highest prevalence of DON. Besides, a 2022 investigation [5]pointed out that 100% of the corn kernels from this region were co-contaminated with at least two mycotoxins, particularly the combination of DON and FUM. Because the Middle East and North Africa are expected to become the hot spots for all common Fusarium mycotoxins in the future, livestock farmers and the feed industry who have crop sources and animal feed from this area need to track the concentrations of Fusarium mycotoxins regularly.

5.2 Sub-Saharan Africa

Compared to the other regions, Sub-Saharan Africa was one of the few areas where DON was not one of the top three prevalent mycotoxins, and this toxin had a 49.5% positive rate in cereal and complete feed with 352 μg/kg from 2008 to 2017 [1]. Deoxynivalenol prevalence reached 71% and 61% in 2020 and 2021, respectively [8,9]. However, a 2022 global survey [5] mentioned DON reverted to 47% occurrence in Sub-Saharan African feed ingredients and animal feed.

5.3 South Africa

From 2008 to 2017 [1], DON was the most prevalent mycotoxin in South African feed ingredients and animal feed and was detected in 63.2% and 363 μg/kg of samples, respectively. It should be noted that DON concentration was low in maize in 2016 and 2017. Although South African grain and balanced feed had previously been exposed to DON contamination, it had not been one of the most prevalent regions around the world. However, due to heavy rainfall caused by climate change, DON’s positive rate in cereal and complete feed has increased significantly in South Africa, making the region the third most prevalent in terms of DON contamination in the world. Deoxynivalenol prevalence in feed ingredients and animal feed peaked at 77% in 2020 and 2022, with a brief dip to 61% in 2021 [5,8,9]. 

6. Oceania

In grain and balanced feed from Oceania, DON was the most frequently detected mycotoxin, with 34.5% positive samples from 2008 to 2017 [1]. In another survey, DON was found in only 18% of cereal and complete feed [13]. In 2022, DON was the second most prevalent mycotoxin, at a positive rate of only 25% [5]. It is noteworthy that many studies indicated that Oceania presented the lowest rate of all mycotoxins analyzed, and the risk for animal production was considered low to moderate.

7. Co-occurrence

A considerable amount (38% to 64%) of cereal and complete feed around the world are contaminated with more than one mycotoxin [1]. This high frequency of co-contamination shows the need to investigate the association and the interaction of the effects of co-occurring mycotoxins in animals [14]. For instance, feeds naturally contaminated with DON and other mycotoxins may impair swine growth at 0.6 mg/kg, whereas for feeds that are artificially contaminated with purified DON, growth impairment is observed at 1.8 mg/kg [15].

Deoxynivalenol co-occurs with other Fusarium mycotoxins, mainly ZEN and FUM [1]. Zearalenone and deoxynivalenol are produced by F. graminearum while deoxynivalenol and fumonisin are produced by F. culmorum, which show the ideal moisture and temperature for Fusaria growth are the same; only the temperature of mycotoxin production is slightly different: cooler environments induce ZEN and FUM production, while temperate regions are better suited for DON production [16,17]. It should be noted that DON and ZEN and DON and FUM were the most frequently observed mycotoxin combinations in feed ingredients and animal feed [1]. A global decade-long survey [1] showed that the co-occurrences of DON and ZEN and DON and FUM were detected at the same positive rate (48%) in finished feed, 39% and 49% in maize, as well as 28% and 8% in wheat, respectively. 

8. References

1. Gruber-Dorninger, C.; Jenkins, T.; Schatzmayr, G. Global Mycotoxin Occurrence in Feed: A Ten-Year Survey. Toxins (Basel) 2019, 11, doi:10.3390/toxins11070375.

2. Liu, J.; Applegate, T. Zearalenone (ZEN) in Livestock and Poultry: Dose, Toxicokinetics, Toxicity and Estrogenicity. Toxins (Basel) 2020, 12, doi:10.3390/toxins12060377.

3. van Asselt, E.D.; Booij, C.J.H.; van der Fels-Klerx, H.J. Modelling mycotoxin formation by Fusarium graminearum in maize in The Netherlands. Food Additives & Contaminants: Part A 2012, 29, 1572-1580, doi:10.1080/19440049.2012.688877.

4. Roige, M.B.; Aranguren, S.M.; Riccio, M.B.; Pereyra, S.; Soraci, A.L.; Tapia, M.O. Mycobiota and mycotoxins in fermented feed, wheat grains and corn grains in Southeastern Buenos Aires Province, Argentina. Rev Iberoam Micol 2009, 26, 233-237, doi:10.1016/j.riam.2009.03.003.

5. DSM. DSM World Mycotoxin Survey 2022; 2023.

6. Kochiieru, Y.; Mankeviciene, A.; Ceseviciene, J.; Semaskiene, R.; Dabkevicius, Z.; Janaviciene, S. The influence of harvesting time and meteorological conditions on the occurrence of Fusarium species and mycotoxin contamination of spring cereals. J Sci Food Agric 2020, 100, 2999-3006, doi:10.1002/jsfa.10330.

7. Commission, E. Commission recommendation of of 17 august 2006 on the presence of deoxynivalenol, zearalenone, ochratoxin a, T-2 and HT-2 and fumonisins in products intended for animal feeding. Commission, E., Ed. Official Journal of the European Union: 2006.

8. BIOMIN. Biomin World Mycotoxin Survey 2020; 2021.

9. DSM. DSM World Mycotoxin Survey 2021; 2022 

10. Yli-Mattila, T.; Hussien, T.; Abbas, A. Comparison of biomass and deoxynivalenol production of northern European and southern European Fusarium graminearum isolates in the infection of wheat and oat grains. Journal of Plant Pathology 2022, 104, 1465-1474, doi:10.1007/s42161-022-01233-9.

11. Esp. M.V. Bruno Vecchiy, M.M.V.E.M.T. Prevalence in Latin America 2021 Survey; Vetanco: 2022.

12. Chen, C.; Turna, N.S.; Wu, F. Risk assessment of dietary deoxynivalenol exposure in wheat products worldwide: Are new codex DON guidelines adequately protective? Trends in Food Science & Technology 2019, 89, 11-25, doi:https://doi.org/10.1016/j.tifs.2019.05.002.

13. Rodrigues, I.; Naehrer, K. A three-year survey on the worldwide occurrence of mycotoxins in feedstuffs and feed. Toxins (Basel) 2012, 4, 663-675, doi:10.3390/toxins4090663.

14. Hao, W.; Guan, S.; Li, A.; Wang, J.; An, G.; Hofstetter, U.; Schatzmayr, G. Mycotoxin Occurrence in Feeds and Raw Materials in China: A Five-Year Investigation. Toxins (Basel) 2023, 15, doi:10.3390/toxins15010063.

15. Dersjant-Li, Y.; Verstegen, M.W.; Gerrits, W.J. The impact of low concentrations of aflatoxin, deoxynivalenol or fumonisin in diets on growing pigs and poultry. Nutr Res Rev 2003, 16, 223-239, doi:10.1079/NRR200368.

16. Velluti, A.; Marín, S.; Gonzalez, R.; J Ramos, A.; Sanchis, V. Fumonisin B1, zearalenone and deoxynivalenol production by Fusarium moniliforme, F proliferatum and F graminearum in mixed cultures on irradiated maize kernels. Journal of the Science of Food and Agriculture 2001, 81, 88-94, doi:https://doi.org/10.1002/1097-0010(20010101)81:1<88::aid-jsfa787>3.0.CO;2-Q.

17. Yazar, S.; Omurtag, G.Z. Fumonisins, trichothecenes and zearalenone in cereals.