Survey and risk assessment of the mycotoxins deoxynivalenol,zearalenone, fumonisins,ochratoxin A,and aflatoxins in commercial dry dog food

The aim of the present study was to investigate the occurrence of mycotoxins in commercial dog food, as a basis to estimate the risk of adverse effects. Seventy-six dry dog food samples from 27 producers were purchased from retail shops, supermarkets, and specialized pet food shops in Vienna, Austria. The frequency and levels of deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM), ochratoxin A (OTA). and aflatoxins (AF) in dry dog food were determined. Mycotoxin analysis were performed by commercial enzyme-linked immunosorbent assay (ELISA) test kits. Confirmatory analyses were done for DON, ZEA, and FUM by high performance liquid chromatography (HPLC) after extract clean-up with immunoaffinity columns. The correlations between ELISA and HPLC results for DON and ZEA were acceptable and indicated that ELISA could be a simple, low cost, and sensitive screening tool for mycotoxins detection, contributing to quality and safety of pet food. DON was the mycotoxin most frequently found (83% positives; median 308 μg/kg, maximum 1,390 μg/kg). ZEA (47% positives, median 51 μg/kg and maximum 298 μg/kg) and FUM (42% positives, median 122 μg/kg and maximum 568 μg/kg) were also frequently detected in dog food. OTA was less frequently found (5%, median 3.6 μg/kg, maximum 4.7 μg/kg. AF were not detected (<0.5 μg/kg) in any sample. The results show that dry dog food marketed in Vienna are frequently contaminated with mycotoxins (DON > ZEA > FUM > OTA) in low concentrations, but do not contain AF. The high frequency of Fusarium toxins DON, ZEA, and FUM indicates the need for intensive control measures to prevent mycotoxins in dog foods. The mycotoxin levels found in dry dog food are considered as safe in aspects of acute mycotoxicoses. However, repeated and long-time exposure of dogs to low levels of mycotoxins may pose a health risk.     

Simultaneous occurrence of mycotoxins in human food commodities from Cameroon

Eighty-two samples of dried food commodities from Cameroon were screened and quantified for different mycotoxins, including fumonisin B₁ (FB₁), zearalenone (ZEA), deoxynivalenol (DON), aflatoxin (AF) and ochratoxin A (OTA), by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively. The percentage of positive samples was as follows: FB₁ 41%, AF 51%, ZEA 57%, DON 65% and OTA 3%. High FB₁ contents were found in maize, averaging 3,684 μg/kg (range: 37-24,225 μg/kg), whereas the highest average ZEA level was found in peanuts (70 μg/kg), followed by maize (69 μg/kg), rice (67 μg/kg) and beans (48 μg/kg) with no ZEA was detected in soybeans. DON contents were low, ranging from 13 to 273 μg/kg, and for AF the average content was 2.6 μg/kg with peanuts and maize as principal substrates. The incidence of OTA was low, with a mean level of 6.4 μg/kg recorded. The majority (79%) of samples contained more than one mycotoxin and the most frequent co-occurrence found was FB₁ + ZEA + DON, detected in 21% of samples (mainly maize) analysed. Co-contamination with FB₁ + ZEA + DON + AF was found in 11% of the samples. Although a large proportion of samples had fairly low levels of individual mycotoxins, this should be of concern as the co-occurrence of mycotoxins may generate additive or synergistic effect in humans, especially if the respective commodities are consumed almost on a daily basis.     

Ochratoxin A in airborne dust and fungal conidia

Farm workers are often exposed to high concentrations of airborne organic dust and fungal conidia, especially when working with plant materials. The purpose of this investigation was to study the possibility of exposure to the mycotoxin ochratoxin A (OTA) through inhalation of organic dust and conidia. Dust and aerosol samples were collected from three local cowsheds. Aerosol samples for determination of total conidia and dust concentrations were collected by stationary sampling on polycarbonate filters. Total dust was analysed by gravimetry, and conidia were counted using scanning electron microscopy. A method was developed for extraction and determination of OTA in small samples of settled dust. OTA was extracted with a mixture of methanol, chloroform, HCI, and water, purified on immunoaffinity column, and analysed by ion-pair HPLC with fluorescence detection. Recovery of OTA from spiked dust samples (0.9–1.0 μg/kg) was 74% (quantitation limit 0.150 μg/kg). OTA was found in 6 out of 14 settled dust samples (0.2–70 μg/kg). The total concentration of airborne conidia ranged from < 1.1 × 10⁴ to 3.9 × 15⁵ per m³, and the airborne dust concentration ranged from 0.08 to 0.21 mg/m³. Conidia collected from cultures of Penicillium verrucosum and Aspergillus ochraceus contained 0.4–0.7 and 0.02–0.06 pg OTA per conidium, respectively. Testing of conidial extracts from these fungi in a Bacillus subtilis bioassay indicated the presence of toxic compounds in addition to OTA. The results show that airborne dust and fungal conidia can be sources of OTA. Peak exposures to airborne OTA may be significant, e.g., in agricultural environments. This revised version was published online in August 2006 with corrections to the Cover Date.     

Co-occurrence of mycotoxins in swine feed produced in Portugal

A total of 404 samples of commercial swine feed from Portugal feed mills were analysed by HPLC methods for the presence of mycotoxins: 277 samples of feed for fattening pigs were analysed for ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON), and 127 samples of feed for sows were analysed for ZEA and fumonisins (FB₁ + FB₂). Concerning feed for fattening pigs, 21 (7.6%) samples were positive for OTA, (2–6.8 μg/kg), 69 (24.9%) were positive for ZEA (5–73 μg/kg), and 47 (16.9%) were positive for DON (100–864 μg/kg). In feed for sows, the results showed 29.9% of positive samples for ZEA (5–57.7 μg/kg) and 8.7% positive samples for FB₁ and FB₂ (50–391.4 μg/kg). Co-occurrence of DON/ZEA was found most frequently, but simultaneous contamination with OTA/ZEA and OTA/DON was also found.     

Biomonitoring of ochratoxin A in grain workers

Handling agricultural commodities such as grain can result in an inhalation of mycotoxin-containing dusts. Ochratoxin A (OTA) is particularly well suited for biomonitoring studies due to its long half-life in blood, and served as a marker toxin to investigate whether or not exposure to dusts in occupational contexts may result in elevated OTA blood serum levels. OTA analysis was performed for blood samples (n=61) obtained from a cohort of male workers employed at granaries of several grain handling companies in Germany. OTA was analyzed in plasma extracts by HPLC with fluorimetric detection; calibration curves were run for each batch of samples collected between July 2005 and March 2006, and the level of detection was 0.05 ng/ml plasma. The OTA plasma levels of the 61 grain workers ranged between 0.07 ng/ml and 0.75 ng/ml. The mean (0.28±0.13 ng/ml) and median (0.26 ng/ml) OTA value for this cohort was similar to average values previously reported for the German population. Our results gave no indication that OTA in excess of those originating from typical dietary sources was ingested by these workers. Although measurable OTA concentrations have been found in dust samples collected at the corresponding workplaces (Mayeret al, this issue), the biomonitoring data do not provide evidence for a significant inhalatory burden of OTA in grain workers. Since deoxynivalenol and zearalenone were also detected in the dust samples in concentrations much higher than that of OTA, additional research should try to assess the potential relevance of an inhalation exposure to these mycotoxins. Presented at the 28^th Mykotoxin-Workshop, Bydgoszcz, Poland, May 29–31, 2006     

Untersuchungen zur Tiergesundheit,Leistung und zum Rückstandsverhalten beim Schwein bei gleichzeitiger Aufnahme der Mykotoxine Ochratoxin A,Deoxynivalenol, Zearalenon über das Futter im 90-Tage-Test

The effect of the administration of the mycotoxins OTA, ZEA and DON alone resp. in combination on animal health and the residue behavior of pigs from 50 – 60 kg living weight over 90 days was investigated in 4 separate studies. Due to its fast metabolisation the administration of 1000 µg DON resp. 250 µg ZEA per kg feed alone or in combination with other mycotoxins does not lead to detectable residues of these mycotoxins in organs and tissues. Therefore these mycotoxins should not be relevant to the consumer.There is an effect of the simultaneous administration of ZEA resp. DON on the metabolisation resp. secretion of OTA. OTA is of relevance from the point of view of residue toxicology.     

Verhalten von Mykotoxinen bei der Ethanolerzeugung aus Getreide

By means of a modelling experiment we followed the fate of deoxynivalenol (DON) and zearalenone (ZEA) in the production of bioethanol from grain. The experiment has been performed at the ‘Versuchs- und Lehranstalt für Brauerei in Berlin e.V.’ A total of 33 kg. triticale with a concentration of 3.2 mg/kg DON and 0.035 mg/kg ZEA were treated with water and enzymes which yielded the mash. By adding yeasts the mixture was then brought to formentation. Finally, the alcohol was obtained by destillation. The residue was dried by centrifugation to a content of 25% dry matter and put in silage tubes. In each part of the whole process test samples were taken and the content of DON and ZEA was determined. After three month the silage was scraped out from the tubes and analyzed, too. The mycotoxins were analyzed by HPLC with DAD and HPLC with fluorescence detection, corresponding to VDLUFA-methods. The balance of the mycotoxin contents showed no loss of DON in the process. For ZEA, however, a deficit of about 35% was noted. Because of the mass loss during starch fermentation (33 kg grain yield 8 kg draff) the mycotoxin contents were enhanced by a factor of 2 to 4. DON is well dissolved in water and therefore partially washed out by filtration of the mash. As the whole process is performed in practice as a cycle, the filtrate with DON is permanently recycled in the brewery process. Therefore the mycotoxin concentration in the original grain should not exceed the legal EU boundary values of 1.25 mg/kg DON and 0.1 mg/kg ZEA.     

Mould and mycotoxin contamination of pig feed in northwest Croatia

The aim of this study was to investigate the contamination of pig feed with moulds and the occurrence of mycotoxins. A total of 30 feed samples were collected at different animal feed factories in the north-western part of Croatia. Mycological analysis showed that the total number of moulds ranged from 1?×?10³ to 1?×?10⁵?cfu/g with samples contaminated with Aspergillus spp. (63?%), Penicillium spp. (80?%), and Fusarium spp. (77?%). A determination of aflatoxin B1 (AFB₁), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), T-2 toxin (T-2) and fumonisin (FUM) concentration was done using the validated ELISA method. The mean concentrations of AFB₁ (0.5?±?0.6???g/kg), OTA (1.53?±?0.42???g/kg) and FUM (405?±?298???g/kg) were below the maximum levels or recommended values in the EU in all the investigated samples. The observed results indicated an increased contamination of pig feed with Fusarium mycotoxins DON and ZEA with mean concentrations of 817?±?447 and 184?±?214???g/kg, higher than recommended in 40 and 17?% of the analysed samples, respectively.     

Natural multi-occurrence of mycotoxins in rice from Niger State,Nigeria

Twenty-one rice samples from field (ten), store (six) and market (five) from the traditional rice-growing areas of Niger State, Nigeria were analysed for aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisin B₁ (FB₁) and B₂ (FB₂), and patulin (PAT) by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) respectively. T-2 toxin was determined using TLC only. AFs were detected in all samples, at total AF concentrations of 28–372 μg/kg. OTA was found in 66.7% of the samples, also at high concentrations (134–341 μg/kg) that have to be considered as critical levels in aspects of nephrotoxicity. ZEA (53.4%), DON (23.8), FB₁ (14.3%) and FB₂ (4.8%) were also found in rice, although at relatively low levels. T-2 toxin was qualitatively detected by TLC in only one sample. Co-contamination with AFs, OTA, and ZEA was very common, and up to five mycotoxins were detected in a single sample. The high AF and OTA levels as found in rice in this study are regarded as unsafe, and multi-occurrences of mycotoxins in the rice samples with possible additive or synergistic toxic effects in consumers raise concern with respect to public health.     

Effects of Fusarium mycotoxins on steroid production by porcine granulosa cells

Fusarium mycotoxins, such as trichothecenes and zearalenone, are common grain and foodstuffs contaminants. Some of these like deoxynivalenol (DON) can negatively impact pregnancy success in swine, but evidence for direct ovarian effects of DON, zearalenone, and its major metabolite, alpha-zearalenol (ZEA) is meager. To evaluate the effects of two mycotoxins, DON and ZEA on porcine granulosa cell(s) (GC) proliferation, steroidogenesis and gene expression, pig GC from small follicles (1-5mm) were cultured for 2 days in 5% fetal bovine serum and 5% porcine serum-containing medium followed by 2 days in serum-free medium containing control (no mycotoxins) or mycotoxins (at various doses/combinations). Both DON and ZEA had biphasic effects on IGF-I-induced estradiol production, increasing estradiol production at smaller doses and inhibiting at larger doses. ZEA at 3,000 ng/mL (9.37 microM) increased IGF-I-induced progesterone production and at 30 ng/mL (0.0937 microM) and 300 ng/mL (0.937 microM) were without effect, but these doses of ZEA increased FSH-induced progesterone production. ZEA at 3,000 ng/mL inhibited FSH plus IGF-I-induced CYP19A1 and CYP11A1 mRNA abundance. DON inhibited progesterone production at 100 ng/mL (0.337 microM) and 1,000 ng/mL (3.37 microM) but at 10 ng/mL (0.0337 microM) was without effect. DON at 1,000 ng/mL (but not at 10 ng/mL) completely inhibited FSH plus IGF-I-induced CYP19A1 and CYP11A1 mRNA abundance. The concomitant treatment of ZEA had little effect on the dose response to DON. DON increased IGF-I-induced cell numbers at 10 and 100 ng/mL and inhibited cell numbers at 1,000 ng/mL, whereas ZEA had no effect on GC numbers. Only a combined treatment of DON and ZEA increased serum-induced cell proliferation. In conclusion, mycotoxins have direct dose-dependent effects on GC proliferation, steroidogenesis and gene expression. These direct ovarian effects could be one mechanism whereby contaminating Fusarium mycotoxins in feedstuffs could impact reproductive performance in swine.     

Fusarium spp. and Fusarium mycotoxins in maize: a problem for Flanders?

Fusarium species cause not only root, stem and ear rot with severe reductions in crop yield, they produce also toxic secondary metabolites (mycotoxins) such as deoxynivalenol (DON) and zearalenone (ZEA). During several growing seasons the presence of Fusarium spp was followed up. DON and ZEA were determined and related to infection levels. The distribution of DON and ZEA in the different plant parts was studied as well as the influence of the ensiling process on the mycotoxin content. More or less important varietal differences in susceptibility for Fusarium spp. could be detected. DON and ZEA were clearly present in most of the analysed samples. No clear relationship could be detected between visual disease symptoms and mycotoxin content. The accumulation of DON and ZEA was different for the analysed aerial plant parts. The ensiling process gave no reduction of the mycotoxin content.     

Natural occurrence of Fusarium mycotoxins (trichothecenes and zearalenone) in barley and corn in Korea.

Barley is produced in four provinces, Chonbuk, Chonnam, Kyungbuk, and Kyungnam, and corn is mainly produced in the Kangwon province in Korea. The natural occurrence of Fusarium mycotoxins was surveyed in 39 barley and 46 corn samples from different areas. Five 8-ketotrichothecenes, namely deoxynivalenol (DON), nivalenol (NIV), 4-acetylnivalenol (4-ANIV), 3-acetyldeoxynivalenol (3-ADON), and 4,15-diacetylnivalenol (4,15-DANIV), and zearalenone (ZEA) were detected in barley. DON, NIV, and ZEA were the major contaminants in barley, with mean levels of 170, 1,011, and 287 ng/g, respectively. On the other hand, DON, 15-acetyldeoxynivalenol (15-ADON), NIV, 4-ANIV, 4,15-DANIV, and ZEA were detected in corn samples. DON and 15-ADON were the major contaminants in corn, with mean levels of 310 and 297 ng/g, respectively. The survey indicated that the natural occurrence of monoacetyl-DON and the ratios of NIV to DON in two cereals were different. In addition, this is the first report of the natural occurrence of 4,15-DANIV in cereals.     

Mycoflora and incidence of aflatoxin B1, zearalenone and deoxynivalenol in poultry feeds in Argentina

In Argentina, there is rather little information about the natural occurrence of mycotoxins in feedstuffs. The aim of this work was to determine the fungal flora and natural incidence of aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON) in poultry feeds from 5 factories of Río Cuarto, Córdoba. Three hundred samples were taken from May 1995 to May 1996. Fungal counts of poultry feeds ranged 104 to 106 CFU g-1. The lowest counts were obtained on the first months from the sampling (May to September 1995) with mean values significantly different from those found at the last of the sampling (October 1995 to April 1996). The most prevalent species isolated of poultry feed samples belonged to the genera Penicillium that was present in 98% of the samples, Fusarium (87%) and Aspergillus (52%). Fusarium species isolated were: F moniliforme in 73% of the samples, F subglutinans (35%), F graminearum (20%) and within Aspergillus species: A. parasiticus (33%) and A. flavus (8%) were identified. In poultry feeds aflatoxin B1 (AFB1) was the most significant mycotoxin with levels ranging from 17 to 197 ng/g. For deoxynivalenol (DON) the levels ranged from 240 to 410 ng/g. Only three out of 300 samples were contaminated with zearalenone (ZEA) in concentrations of 30, 120 and 280 ng/g. These are preliminary data on this subject in our region. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mycotoxins in several Polish food products in 2004–2005

In 2004–2005, samples of several selected Polish foods such as cereal products, nuts, dried fruits, coffee and culinary spices collected from Warsaw market and taken from food producers were analyzed on presence of aflatoxin B₁, B₂, G₁, G₂ (AF), ochratoxin A (OTA), zearalenone (ZEA) and deoxynivalenol (DON). After extraction and clean-up of extracts on immunoaffinity columns (IAC), mycotoxin analyses were carried out by HPLC using fluorescence and UV detectors. The concentrations of aflatoxins and ochratoxin A depending on the kind of sample ranged from 0.02 to 7.8 (one sample, of peanuts) and 0.02–11.9 μg/kg (one coffee sample), respectively. The levels of ZEA and DON were found to be below 50 °g/kg.     

Natural Occurrence of Mycotoxins in Staple Cereals from Ethiopia

The occurrence of mycotoxins in barley, sorghum, teff (Eragrostis tef) and wheat from Ethiopia has been studied. Samples were analyzed for aflatoxin B₁ (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) using high performance liquid chromatography (HPLC) and for fumonisins (FUM) using enzyme linked immunosorbent assay (ELISA). AFB1 and OTA were detected in samples of all the four crops. AFB1 was detected in 8.8% of the 352 samples analyzed at concentrations ranging from trace to 26 μg kg⁻¹. OTA occurred in 24.3% of 321 samples at a mean concentration of 54.1 μg kg⁻¹ and a maximum of 2106 μg kg⁻¹. DON occurred in barley, sorghum and wheat at 40–2340 μg kg⁻¹ with an overall incidence of 48.8% among the 84 mainly ‘suspect’ samples analyzed; NIV was co-analyzed with DON and was detected at 40 μg kg⁻¹ in a wheat sample and at 50, 380, and 490 μg kg⁻¹ in three sorghum samples. FUM and ZEN occurred only in sorghum samples with low frequencies at concentrations reaching 2117 and 32 μg kg⁻¹, respectively. The analytical results indicate higher mycotoxin contamination in sorghum, which could be related to the widespread storage of sorghum grain in underground pits leading to elevated seed moisture contents. This is the first report on the occurrence of OTA in teff.     

Exposure of oocytes to the Fusarium toxins zearalenone and deoxynivalenol causes aneuploidy and abnormal embryo development in pigs

Fungi of the Fusarium species can infect food and feed commodities and produce the mycotoxins zearalenone (ZEA) and deoxynivalenol (DON). Since both toxins have been reported to reduce fertility, the mechanisms of ZEA and DON on inhibition of oocyte maturation were examined. Pig oocytes were matured in the presence of ZEA (a mycotoxin with estrogenlike activity), 17beta-estradiol, and DON (all 3.12 micromol/L). Zearalenone, 17beta-estradiol, and DON inhibited oocyte maturation and caused approximately 34% of the oocytes to form an aberrant spindle. Different ratios of ZEA:DON did not lead to a more severe inhibition of oocyte maturation. Both mycotoxins caused abnormal formation of the meiotic spindle. The developmental competence of oocytes matured in the presence of mycotoxins was further investigated after in vitro fertilization. Presence of ZEA (3.12 micromol/L) during maturation reduced the percentages of oocytes that cleaved and formed a blastocyst to about 12%, compared with 25% of control oocytes. Maturation in the presence of equimolar concentrations of DON was not compatible with development. The ploidy of blastomeres from blastocysts derived from mycotoxin-exposed oocytes was analyzed with fluorescent in situ hybridization. All blastocysts, even those from the control group, contained at least one blastomere with abnormal ploidy, but the variation in the percentages of aneuploid blastomeres was significantly larger in embryos from oocytes exposed to mycotoxins. It is concluded that ZEA and DON can lead to abnormal spindle formation, leading to less fertile oocytes and embryos with abnormal ploidy, and that the effects of ZEA and DON are not synergistic.     

Mykotoxine in futtergetreideproben aus landwirtschaftlichen Betrieben in Bayern (Ernte 1991-2000)

Feed grain production for on-farm use is widespread in Bavarian agriculture and garants a reliable production of healthy foodstuff. Therefore the quality of feed grain is very important for farmers. In an orientating investigation of the on-farm stored feed grain quality from the harvest years 1991 to 2000 1757 samples were analysed. Based on values for guidance by the German government for DON and ZEA and Commission Regulation EC No 472/2002 for OTA the results show that only 2% of the positive samples have amounts higher then 0,05 mg ZEA/kg grain, 4% of the positive samples contain more then 1 mg DON/kg grain and 2% of the positive samples have amounts higher then 0,003 mg OTA/kg feed grain. These illustrate the good conservation and storage quality on Bavarian farms.     

Mycotoxins in horse feed

A total of 62 samples of commercial horse feed preparations (complementary feeds) containing cereal mixtures (“muesli” or mash, n = 39; pelleted feeds, n = 12), and plain horse feed grains (maize, n = 5; oats, n = 4; barley, n = 2) were purchased from 21 different producers/distributors from the German market. All samples were analysed by competitive enzyme immunoassays (EIA) for six different mycotoxins (mycotoxin groups). Analytes (detection limit, mean recovery) were: deoxynivalenol (DON, 10 μg/kg, 84%), zearalenone (ZEA, 5 μg/kg, 93%), fumonisin B₁ (FB₁, 2 μg/kg, 113%), T-2 toxin (T-2, 0.1 μg/kg, 71%), sum of T-2 + HT-2 toxin (T-2/HT2, 0.2 μg/kg, 97%), ochratoxin A (OTA, 0.2 μg/kg, 67%), and total ergot alkaloids (Generic Ergot Alkaloids “GEA”, 30 μg/kg, 132%). All samples contained DON (16–4,900 μg/kg, median 220 μg/kg), T-2/HT-2 (0.8–230 μg/kg, median 24 μg/kg), and T-2 (0.3–91 μg/kg, median 7 μg/kg). ZEA was detected in 98% of the samples (7–310 μg/kg, median 61 μg/kg). Most samples (94%) were positive for FB₁ (2–2,200 μg/kg, median 27 μg/kg). Ergot alkaloids were detected in 61% of samples (28–1,200 μg/kg, median 97 μg/kg), OTA was found in 42% of samples (0.2–4 μg/kg, median 0.35 μg/kg). The results demonstrate that a co-contamination with several mycotoxins is very common in commercial horse feed from the German market. The toxin concentrations were in most cases well below the levels which are usually considered as critical or even toxic. The highest mycotoxin concentrations were mostly found in single-grain cereal feed: the maximum values for DON and FB₁ were found in maize, the highest T-2/HT-2 toxin concentrations were found in oats, and the highest concentration of ergot alkaloids was found in barley. In composed feeds, no correlation between cereal composition and mycotoxin levels could be found.     

A review on comparative data concerning <Emphasis Type="Italic">Fusarium</Emphasis> mycotoxins in Bt maize and non-Bt isogenic maize

The European corn borer reportedly promotes the infection of maize by Fusarium spp. Stalk and ear rots caused by Fusarium spp. are often related to mycotoxin accumulation in maize kernels. As a result, food and animal feed from maize are more severely contaminated with Fusarium mycotoxins: e.g. fumonisins (FUM), deoxynivalenol (DON) and zearalenone (ZEA). Bt maize is primarily an important potential tool for insect pest protection, both in the European Union and in other countries. Bt maize carrying the Bt genes is highly resistant to European corn borer larval feeding due to Bt toxin (δ toxin) production. Effective measures to combat pests therefore often have a positive side-effect in that they also reduce mycotoxin levels. Comparative analysis was used to the evaluation of the studies dealing with the reduction of Fusarium mycotoxins in Bt maize. Nineteen out of 23 studies on Bt maize came to the conclusion that Bt maize is less contaminated with mycotoxins (FUM, DON, ZEA) than the conventional control variety in each case.     

Nachweis von Fusarien und deren Mykotoxinen in Futterkonservaten aus Grünlandbeständen mit differenzierter Bewirtschaftungsintensität

Conservation forage (17 hay and 18 grass silage samples) from 15 farms with different intensities of grassland management in the Federal State of Brandenburg were examined for contamination with fusaria and their mycotoxins. The numbers of culturable filamentous fungi in hay were determined by plate counting andFusarium isolates were classified taxonomically. The mycotoxins Zearalenone (ZEA) and Deoxynivalenol (DON) were extracted from hay as well as silage by different procedures and detected chromatographically (HPLC). The numbers of filamentous fungi in the hay samples were 10² and 10⁶ CFU/g FM independently of intensive or extensive management. Only fourFusarium species were identified.Fusarium culmorum, a potential toxin producing species, was most frequently detected (52% of all isolates). ZEA was found in two hay and four silage samples (6-66 μg/kg), DON in three hay and seven silage samples (63–1290 μg/kg). There were no differences between forage samples of extensive and intensive cultivated grassland of the year 2003 regarding numbers of fusaria and the content of their mycotoxins.

Presented at the 26^th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004.