Practical Application of a Urinary Zearalenone Monitoring System for Feed Hygiene Management of a Japanese Black Cattle Breeding Herd-Relevance to Anti-Müllerian Hormone and Serum Amyloid A Clarified from a Two-Year Survey

In this study, a herd of Japanese Black (JB) breeding cattle with sporadic reproductive disorders was continuously monitored for an additional year to assess the effects of the urinary zearalenone (ZEN) concentration and changes in parameters (AMH and SAA) with time-lag variables and herd fertility (reproductive performance). This herd had high (exceeded the Japanese dietary feed regulations) urinary ZEN and rice straw ZEN concentrations (1.34 mg/kg). Long-term data of the herd with positive ZEN exposure revealed a decreasing ZEN concentration in urine and a gradual decrease in the AMH level with age. The AMH level was significantly affected by the ZEN value 2 months earlier and the AMH level in the previous month. The changes in ZEN and SAA values were significantly affected by the ZEN and SAA values in the previous month. Additionally, calving interval data between pre-monitoring and post-monitoring showed a significantly different pattern. Furthermore, the calving interval became significantly shorter between the time of contamination (2019) and the end of the monitoring period (2022). In conclusion, the urinary ZEN monitoring system may be a valuable practical tool for screening and detecting herd contamination in the field, and acute and/or chronic ZEN contamination in dietary feeds may affect herd productivity and the fertility of breeding cows.

In vitro effect of zearalenone on sperm parameters, oocyte maturation and embryonic development in buffalo

The negative impact of zearalenone (ZEN; potent estrogenic mycotoxin) exposure on buffalo embryo production has not yet been determined. In the current study, buffalo sperm and oocytes were exposed to ZEN at different concentrations during maturation. Sperms (with and without ZEN exposure) were incubated for 2 h and evaluated for motility, viability, acrosome integrity, normality, and ultrastructure. Matured oocytes exposed to ZEN were stained to determine their nuclear maturation. Further, their developmental ability was evaluated after in vitro fertilization. Our results showed the toxic effects of ZEN at high concentrations (2000 ng/mL) on different buffalo sperm parameters. The number of acrosome-intact sperm was reduced at 0 h after exposure to a concentration of ≥ 100 ng/mL. Furthermore, the maturation rate of buffalo oocytes (telophase I + metaphase II) was significantly decreased in ZEN-treated oocytes with a higher degeneration rate. Oocytes matured in 1000 ng/mL ZEN and subsequently exhibited considerable reduction in cleavage rate and blastocyst formation compared with control oocytes (2.6% vs. 13.1%). Moreover, the morula rate was decreased (p < 0.001) in ZEN-treated oocytes at concentrations of ≥ 10 ng/mL. Overall, the adverse effects of in vitro ZEN exposure on buffalo sperm parameters and oocyte meiotic progression with a notable reduction in cleavage, morula, and blastocyst rates were defined by these results. Altogether, buffaloes should be considered sensitive to ZEN exposure with respect to their reproductive function.

Zearalenone (ZEN) and Its Metabolite Levels in Tissues of Wild Boar (Sus scrofa) from Southern Italy: A Pilot Study

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by the fungi of the Fusarium genera, and is a contaminant of cereals and plant products. ZEN and its metabolites are considered endocrine disruptors, and could have various toxic effects on animals and humans. In recent years, there has been a significant demographic increase in wild boar (Sus scrofa) in many mountainous and hilly areas of Italy, including the Campania region, mainly due to global climate change. The wild boar can be defined as a generalist and omnivorous species capable of varying its diet; therefore, it can play a role as an environmental bioindicator towards contaminants such as mycotoxins. This study was conducted to evaluate, for the first time, the concentrations of ZEN and its metabolites in the liver, kidney, and muscle of 82 wild boars shot in their habitat by hunters with hunting permits in different localities of Avellino province (Campania region, Southern Italy) from 2021 to 2022. The samples were collected and analyzed with an SPE clean-up and high-pressure liquid chromatography method with fluorescence detection. The results indicated that ZEN and α-Zearalenol were present in most of the samples, suggesting that a plan to monitor these mycoestrogens is essential to achieve the goals of "One Health".

Practical Application of Urinary Zearalenone Monitoring System for Feed Hygiene Management of a Japanese Black Cattle Breeding Herd—The Relationship between Monthly Anti-Müllerian Hormone and Serum Amyloid A Concentrations

This study addresses an advantageous application of a urinary zearalenone (ZEN) monitoring system not only for surveillance of ZEN exposure at the production site of breeding cows but also for follow-up monitoring after improvement of feeds provided to the herd. As biomarkers of effect, serum levels of the anti-Müllerian hormone (AMH) and serum amyloid A (SAA) concentrations were used. Based on the results of urinary ZEN measurement, two cows from one herd had urinary ZEN concentrations which were two orders of magnitude higher (ZEN: 1.34 mg/kg, sterigmatocystin (STC): 0.08 mg/kg in roughages) than the levels of all cows from three other herds (ZEN: not detected, STC: not detected in roughages). For the follow-up monitoring of the herd with positive ZEN and STC exposure, urine, blood, and roughage samples were collected from five cows monthly for one year. A monitoring series in the breeding cattle herd indicated that feed concentrations were not necessarily reflected in urinary concentrations; urinary monitoring assay by ELISA may be a simple and accurate method that reflects the exposure/absorption of ZEN. Additionally, although the ZEN exposure level appeared not to be critical compared with the Japanese ZEN limitation in dietary feeds, a negative regression trend between the ZEN and AMH concentrations was observed, indicating that only at extremely universal mycotoxin exposure levels, ZEN exposure may affect the number of antral follicles in cattle. A negative regression trend between the ZEN and SAA concentrations could also be demonstrated, possibly indicating the innate immune suppression caused by low-level chronic ZEN exposure. Finally, significant differences (p = 0.0487) in calving intervals between pre-ZEN monitoring (mean ± SEM: 439.0 ± 41.2) and post-ZEN monitoring (349.9 ± 6.9) periods were observed in the monitored five cows. These preliminary results indicate that the urinary ZEN monitoring system may be a useful practical tool not only for detecting contaminated herds under field conditions but also provides an initial look at the effects of long-term chronic ZEN/STC (or other co-existing mycotoxins) exposure on herd productivity and fertility.

Mitigation of sterigmatocystin exposure in cattle by difructose anhydride III feed supplementation and detection of urinary sterigmatocystin and serum amyloid A concentrations

We evaluated the effects of supplementing cattle feed with difructose anhydride III (DFA III) by measuring urinary sterigmatocystin (STC) concentrations using 20 Japanese Black cattle aged 9–10 months from one herd. DFA III was supplemented for 2 weeks for 10 animals, and non-treated animals served as controls. The natural STC concentration in the dietary feed was 0.06 mgkg-1 (mixture of roughage and concentrate) at the beginning of the study (Day 0). The urine STC concentration was measured using liquid chromatography with tandem mass spectrometry 1 d prior to DFA III administration, 9 and 14 d thereafter, and 9 d following supplementation cessation, concomitant with the measurement of serum amyloid A (SAA). The number of heifers in which STC was detected in the urine was low (10 %) in the DFA III group compared to that (60 %) in the control group on Day 9. After 9 d following supplementation cessation (Day 23), STC concentrations were significantly lower (P=0.032) in the DFA III group than in the control group, although there was no difference in the number of heifers in which urinary STC was detected or in SAA concentrations between the two groups. Our findings demonstrate the effect of DFA III on reducing the urinary concentration of STC in Japanese Black cattle.

Zearalenone and Its Metabolites-General Overview, Occurrence, and Toxicity

Mycotoxins are secondary metabolites of filamentous fungi and represent one of the most common groups of food contaminants with low molecular weight. These toxins are considered common and can affect the food chain at various stages of production, harvesting, storage and processing. Zearalenone is one of over 400 detected mycotoxins and produced by fungi of the genus Fusarium; it mainly has estrogenic effects on various organisms. Contaminated products can lead to huge economic losses and pose risks to animals and humans. In this review, we systemize information on zearalenone and its major metabolites.

Mycotoxin-contaminated diets and an adsorbent affect the performance of Nellore bulls finished in feedlots

Mycotoxins are present in almost all feedstuffs used in animal nutrition but are often ignored in beef cattle systems, even though they can affect animal performance. The objective of this study was to evaluate the effects of mycotoxins and a mycotoxin adsorbent (ADS) on performance of Nellore cattle finished in a feedlot. One hundred Nellore cattle (430 ± 13 kg) were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. The factors consisted of two diets with either natural contamination (NC) or exogenous contamination (EC) and the presence (1 g/kg of DM; ADS) or absence of a mycotoxin adsorbent. The NC and EC diets had the following contaminations, respectively: 0.00 and 10.0 µg/kg aflatoxins, 5114 and 5754 µg/kg fumonisins, 0.00 and 42.1 µg/kg trichothecenes B, 0.00 and 22.1 µg/kg trichothecenes A and 42.9 and 42.9 µg/kg fusaric acid. At the beginning of the experiment, all animals were weighed, and four randomly selected animals were slaughtered to evaluate the initial carcass weight. After 97 days of treatment, all animals were weighed and slaughtered. There was no interaction among factors for the DM intake (DMI; P = 0.92); however, there was a tendency for the EC diets to decrease the DMI by 650 g/day compared to animals fed NC diets (P = 0.09). There was a trend for interaction among factors (P = 0.08) for the average daily gain (ADG), where the greatest ADG was observed for cattle fed the NC diet (1.77 kg), and the lowest was observed for those fed the EC diet (1.51 kg). The NC + ADS and EC + ADS treatments presented intermediate values for ADG. The animals fed the NC diet had a greater final BW (596 kg) than animals fed the EC treatment (582 kg; P = 0.04). There was a tendency for interaction among factors for carcass gain (P = 0.08). Similarly to ADG, the highest carcass gain was observed for animals fed the NC diet (1.20 kg), and the lowest was observed for those fed the EC diet (1.05 kg). The NC + ADS and EC + ADS treatments presented intermediate values. The natural contamination groups had greater carcass gain than that of the EC groups, and the use of the ADS recovered part of the weight gain in animals fed the EC diet. In conclusion, mycotoxins at the levels evaluated affected the performance of beef cattle, and adsorbents may mitigate their impact.

The protective effects of modified palygorskite on the broilers fed a purified zearalenone-contaminated diet

This study was conducted to evaluate the protective effects of dietary modified palygorskite (Pal) supplementation on broiler chickens fed a purified zearalenone (ZEN)-contaminated diet. A total of 144 1-day-old male chicks were allocated to one of the 3 treatments, with each treatment being composed of 6 replicates of 8 birds each. The birds were fed with a control diet (Control group), the ZEN-contaminated diet (2.0 mg ZEN/kg diet), and the ZEN-contaminated diet supplemented with 1.0 g/kg diet of modified Pal for 42 d, respectively. Compared with control group, feeding ZEN-contaminated diet reduced weight gain and feed conversion efficiency of broilers during the finisher and overall experimental period (P < 0.05), while the values of these parameters in broilers fed the diet contaminated with ZEN increased after modified Pal administration (P < 0.05). ZEN challenge increased the 21-d serum aspartate aminotransferase and 42-d serum alanine aminotransferase activities, 42-d relative liver weight, and ZEN residues in the liver at both 21 and 42 d and kidney at 42 d (P < 0.05). In contrast, birds fed the ZEN-contaminated diet that was supplemented with modified Pal exhibited lower serum alanine aminotransferase activity at 42 d, relative liver weight at 42 d, and hepatic and renal ZEN accumulation at both 21 and 42 d (P < 0.05), when compared with their counterparts fed the contaminated diet. ZEN contamination decreased superoxide dismutase activity in the serum at 21 d, kidney at 42 d, and liver at both 21 and 42 d, respectively (P < 0.05). The hepatic and renal malondialdehyde accumulation at 42 d increased, while renal glutathione level at 42 d decreased, when feeding broilers with the ZEN-contaminated diet (P < 0.05). Dietary modified Pal supplementation reduced hepatic malondialdehyde accumulation, whereas increased renal superoxide dismutase activity in broilers fed a ZEN-contaminated diet at 42 d (P < 0.05). This finding suggested that dietary modified Pal administration could promote growth performance, reduce hepatonephric ZEN residues, and improve liver function and antioxidant status of broiler chickens receiving a ZEN-contaminated diet.

Fructo-Oligosaccharide (DFA III) Feed Supplementation for Mitigation of Mycotoxin Exposure in Cattle-Clinical Evaluation by a Urinary Zearalenone Monitoring System

The potential effect of difructose anhydride III (DFA III) supplementation in cattle feed was evaluated using a previously developed urinary-zearalenone (ZEN) monitoring system. Japanese Black cattle from two beef herds aged 9⁻10 months were used. DFA III was supplemented for two weeks. ZEN concentrations in feed were similar in both herds (0.27 and 0.22 mg/kg in roughage and concentrates, respectively), and below the maximum allowance in Japan. ZEN, α-zearalenol (α-ZOL), and β-ZOL concentrations in urine were measured using LC/MS/MS the day before DFA III administration, 9 and 14 days thereafter, and 9 days after supplementation ceased. Significant differences in ZEN, α-ZOL, β-ZOL, and total ZEN were recorded on different sampling dates. The concentration of inorganic phosphate in DFA III-supplemented animals was significantly higher than in controls on day 23 (8.4 vs. 7.7 mg/dL), suggesting a possible role of DFA III in tight junction of intestinal epithelial cells. This is the first evidence that DFA III reduces mycotoxin levels reaching the systemic circulation and excreted in urine. This preventive effect may involve an improved tight-junction-dependent intestinal barrier function. Additionally, our practical approach confirmed that monitoring of urinary mycotoxin is useful for evaluating the effects of dietary supplements to prevent mycotoxin adsorption.

A QuEChERS-Based Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of Nine Zearalenone-Like Mycotoxins in Pigs

The determination of zearalenone (ZEN) and its derivatives as biomarkers in animal tissues or organs plays an important role in mycotoxin monitoring and can promote effective exposure assessment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of nine ZEN-like mycotoxins, including three glucuronides in different pig tissues (heart, liver, spleen and muscle) was developed and validated in this study. Tissue samples were extracted using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and clean-up procedure, and analyzed by LC-MS/MS in multiple reaction monitoring (MRM) mode. Dynamic linear ranges for each target analyte were determined with R² between 0.916 and 0.999. The LODs of the six ZENs were achieved in the range of 0.5-1 ng/g and the LOQs varied from 1 ng/g to 2 ng/g. The satisfying intra-day and inter-day reproducibility (both RSDr and RSDR < 20%) indicated a good stability of this method. The recoveries of the nine target analytes were in the range of 70-110%. The validation results showed that this LC-MS/MS method coupled with QuEChERS sample pretreatment is effective and suitable for the simultaneous quantitation of ZEN metabolites in pigs. It has been applied to analysis of the pig tissues in this research and can be also adapted for samples in the mycotoxin research field.

Gas Chromatography-Mass Spectrometry for Metabolite Profiling of Japanese Black Cattle Naturally Contaminated with Zearalenone and Sterigmatocystin

The objective of this study was to evaluate the metabolic profile of cattle fed with or without zearalenone (ZEN) and sterigmatocystin (STC)-contaminated diets using a gas chromatography-mass spectrometry metabolomics approach. Urinary samples were collected from individual animals (n = 6 per herd) from fattening female Japanese Black (JB) cattle herds (23 months old, 550–600 kg). Herd 1 had persistently high urinary ZEN and STC concentrations due to the presence of contaminated rice straw. Herd 2, the second female JB fattening herd (23 months old, 550–600 kg), received the same dietary feed as Herd 1, with non-contaminated rice straw. Urine samples were collected from Herd 1, two weeks after the contaminated rice straw was replaced with uncontaminated rice straw (Herd 1N). Identified metabolites were subjected to principal component analysis (PCA) and ANOVA. The PCA revealed that the effects on cattle metabolites depended on ZEN and STC concentrations. The contamination of cattle feed with multiple mycotoxins may alter systemic metabolic processes, including metabolites associated with ATP generation, amino acids, glycine-conjugates, organic acids, and purine bases. The results obtained from Herd 1N indicate that a two-week remedy period was not sufficient to improve the levels of urinary metabolites, suggesting that chronic contamination with mycotoxins may have long-term harmful effects on the systemic metabolism of cattle.

Measurement of urinary concentrations of the mycotoxins zearalenone and sterigmatocystin as biomarkers of exposure in mares

Mycotoxins may affect animal health, including reproduction. Little is known about the clinical relevance of exposure of horses to contaminated feed. This study aimed at (i) monitoring the levels of the mycotoxins zearalenone (ZEN), with its metabolites α- and β-zearalenol (α- and β-ZOL), and sterigmatocystin (STC) in urine samples from thoroughbred mares in Japan and (ii) relating these findings to the potential effects on reproductive efficacy of breeding mares. Sixty-three urine samples of breeding mares from 59 breeding farms were used. Urine samples and reproductive records were collected from each mare when it was presented to the stallion station. Urinary concentrations of ZEN, α- and β-ZOL, and STC were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). ZEN, α- and β-ZOL were measurable in the urine of all examined mares, indicating the prevalence of ZEN in equine feeds. In seven of the 63 samples, STC was also detected at levels ranging from 1.3 to 18.0 pg/mg creatinine. No significant correlation between the concentrations of mycotoxins and pregnancy status was observed. In conclusion, measurement of mycotoxins in urine samples is a useful non-invasive method for monitoring the systemic exposure of mares to multiple mycotoxins.

Grape Pomace, an Agricultural Byproduct Reducing Mycotoxin Absorption: In Vivo Assessment in Pig Using Urinary Biomarkers

The efficacy of four agricultural byproducts (ABPs) and two commercial binders (CBs) to reduce the gastrointestinal absorption of a mixture of mycotoxins was tested in piglets using urinary mycotoxin biomarkers as indicator of the absorbed mycotoxins. Twenty-eight piglets were administered a bolus contaminated with the mycotoxin mixture containing or not ABP or CB. Twenty-four hour urine was collected and analyzed for mycotoxin biomarkers by using a multiantibody immunoaffinity-based LC-MS/MS method. Each bolus contained 769 μg of fumonisin B1 (FB1), 275 μg of deoxynivalenol (DON), 29 μg of zearalenone (ZEN), 6.5 μg of aflatoxin B1 (AFB1) and 6.6 μg of ochratoxin A (OTA) corresponding to 2.2, 0.8, 0.08, 0.02, and 0.02 μg/g in the daily diet, respectively. The percentage of ABP in each bolus was 50%, whereas for the two CBs the percentages were 5.2 and 17%, corresponding to 2.8, 0.3, and 0.9% in the daily diet, respectively. The reduction of mycotoxin absorption was up to 69 and 54% for ABPs and CBs, respectively. White grape pomace of Malvasia was the most effective material as it reduced significantly (p < 0.05) urinary mycotoxin biomarker of AFB1 (67%) and ZEN (69%), whereas reductions statistically not significant were observed for FB1 (57%), DON (40%), and OTA (27%). This study demonstrates that grape pomace reduces the gastrointestinal absorption of mycotoxins. This agricultural byproduct can be considered an alternative to commercial products and used in the feed industries as an effective, cheap, and natural binder for multiple mycotoxins.

Chemical, physical and technological properties of milk as affected by the mycotoxin load of dairy herds

Abstract. The aim of the study was to determine the impacts of different levels of mycotoxin load of Czech dairy herds on the larger scale of the milk indicators including milk physical and technological properties. During three subsequent years individual milk samples (IMSs) were collected from four herds of Czech Fleckvieh (C) and from four herds of Holstein cows (H). The IMSs were collected regularly twice in summer and twice in winter, resulting in a total of 936 IMSs. The feeding rations consisted mainly of conserved roughage and supplemental mixtures according to milk yield and standard demands. Samples of feedstuffs were collected at the same time as IMSs and were analysed for content of deoxynivalenol (DON), fumonisins (FUM), zearalenone (ZEA), aflatoxin (AFL), and T-2 toxin using enzyme-linked immunosorbent assay (ELISA) methods. Based on the mycotoxin load, herds were divided into three groups – Load 1 (negligible, n =  36), Load 2 (low, n =  192), and Load 3 (medium, n =  708). All feedstuff samples were positive for at least one mycotoxin. The most frequently occurring mycotoxins were FUM, DON, and ZEA. Relatively high incidence of AFL (56 % positive samples) was observed. The following milk indicators were influenced by the mycotoxin load of herds: fat, acetone (Ac), log Ac, pH, electric conductivity, alcohol stability, curds quality, curd firmness, whey volume, whey protein, non-protein nitrogen (NPN), urea N in NPN, fat ∕ crude protein ratio, and casein numbers on crude and true protein basis, respectively (P < 0.05). The overall level of mycotoxin load was relatively low, with no clear effect on milk characteristics.

Natural incidence of zearalenone in Croatian pig feed, urine and meat in 2014

The aim of this study was to determine the levels of zearalenone (ZEN) in different feed materials and feedstuffs for pigs, as well as in pig urine and pig meat following contaminated feed consumption. In total, 253 feed material and feedstuff samples were collected from Croatian pig farms. The results revealed the presence of ZEN in significant concentrations, the maximal being found in maize (5522 µg/kg), wheat (3366 µg/kg) and pig fattening feed (1949 µg/kg). In farms in which high feed contamination and pig hyperestrogenism were observed, samples of pig urine (n=30) and meat (n=30) were retrieved as well. The mean ZEN concentrations in pig urine and pig meat were 206±20.6 µg/L and 0.62±0.14 µg/kg, respectively. Despite high contamination of feedstuffs responsible for farmed pigs' intoxication, ZEN levels determined in pig meat were shown to be of little significance for human safety.

Mycotoxins in silage: checkpoints for effective management and control

Silage has a substantial role in ruminant nutrition. Silages as a source of mycotoxigenic fungi and mycotoxins merit attention. Fungal growth and mycotoxin production before and during storage are a well-known phenomenon, resulting in reduced nutritional value and a possible risk factor for animal health. Mycotoxin co-contamination seems to be unavoidable under current agricultural and silage-making practices. Multi-mycotoxin contamination in silages is of particular concern due to the potential additive or synergistic effects on animals. In regard to managing the challenge of mycotoxins in silages, there are many factors with pre- and post-harvest origins to take into account. Pre-harvest events are predominantly dictated by environmental factors, whereas post-harvest events can be largely controlled by the farmer. An effective mycotoxin management and control programme should be integrated and personalised to each farm at an integrative level throughout the silage production chain. Growing crops in the field, silage making practices, and the feed out phase must be considered. Economical and straightforward silage testing is critical to reach a quick and sufficiently accurate diagnosis of silage quality, which allows for ‘in field decision-making’ with regard to the rapid diagnosis of the quality of given forage for its safe use as animal feed. Regular sampling and testing of silage allow picking up any variations in mycotoxin contamination. The use of rapid methods in the field represents future challenges. Moreover, a proper nutritional intervention needs to be considered to manage mycotoxin-contaminated silages. At farm level, animals are more often exposed to moderate amounts of several mycotoxins rather than to high levels of a single mycotoxin, resulting more frequently in non-specific digestive and health status impairment. Effective dietary strategies to promote rumen health, coupled with the administration of effective and broad-spectrum mycotoxin detoxifiers, are essential to minimise the negative impact of mycotoxins.

Review on Mycotoxin Issues in Ruminants: Occurrence in Forages, Effects of Mycotoxin Ingestion on Health Status and Animal Performance and Practical Strategies to Counteract Their Negative Effects

Ruminant diets include cereals, protein feeds, their by-products as well as hay and grass, grass/legume, whole-crop maize, small grain or sorghum silages. Furthermore, ruminants are annually or seasonally fed with grazed forage in many parts of the World. All these forages could be contaminated by several exometabolites of mycotoxigenic fungi that increase and diversify the risk of mycotoxin exposure in ruminants compared to swine and poultry that have less varied diets. Evidence suggests the greatest exposure for ruminants to some regulated mycotoxins (aflatoxins, trichothecenes, ochratoxin A, fumonisins and zearalenone) and to many other secondary metabolites produced by different species of Alternaria spp. (e.g., AAL toxins, alternariols, tenuazonic acid or 4Z-infectopyrone), Aspergillus flavus (e.g., kojic acid, cyclopiazonic acid or β-nitropropionic acid), Aspergillus fuminatus (e.g., gliotoxin, agroclavine, festuclavines or fumagillin), Penicillium roqueforti and P. paneum (e.g., mycophenolic acid, roquefortines, PR toxin or marcfortines) or Monascus ruber (citrinin and monacolins) could be mainly related to forage contamination. This review includes the knowledge of mycotoxin occurrence reported in the last 15 years, with special emphasis on mycotoxins detected in forages, and animal toxicological issues due to their ingestion. Strategies for preventing the problem of mycotoxin feed contamination under farm conditions are discussed.

Invited review: Diagnosis of zearalenone (ZEN) exposure of farm animals and transfer of its residues into edible tissues (carry over)

The aim of the review was to evaluate the opportunities for diagnosing the zearalenone (ZEN) exposure and intoxication of farm animals by analyzing biological specimens for ZEN residue levels. Metabolism is discussed to be important when evaluating species-specific consequences for the overall toxicity of ZEN. Besides these toxicological facts, analytics of ZEN residues in various animal-derived matrices requires sensitive, matrix-adapted multi-methods with low limits of quantification, which is more challenging than the ZEN analysis in feed. Based on dose-response experiments with farm animals, the principle usability of various specimens as bio-indicators for ZEN exposure is discussed with regard to individual variation and practicability for the veterinary practitioner. ZEN residue analysis in biological samples does not only enable evaluation of ZEN exposure but also allows the risk for the consumer arising from contaminated foodstuffs of animal origin to be assessed. It was compiled from literature that the tolerable daily intake of 0.25 μg ZEN/kg body weight and day is exploited to approximately 8%, when a daily basket of animal foodstuffs and associated carry over factors are assumed at reported ZEN contamination levels of complete feed.

Simultaneous determination of zearalenone, deoxynivalenol and their metabolites in bovine urine as biomarkers of exposure

A feeding trial with 30 dairy cows which were fed rations with three different concentrations of zearalenone (ZEA) and deoxynivalenol (DON) contaminated maize was carried out to examine the ZEA and DON concentration in urine. German Holstein cows (n=30) were divided into three groups (n=10 in each) which received diets with following toxin concentrations: CON (0.02 mg ZEA and 0.07 mg DON, per kg dry matter (DM)), FUS-50 (0.33 mg ZEA and 2.62 mg DON, per kg DM), FUS-100 (0.66 mg ZEA and 5.24 mg DON, per kg DM). For urine analysis, a reliable, cost-efficient and sensitive method for simultaneous determination of ZEA, DON and their metabolites was developed. The method comprises a solid phase extraction clean-up on Oasis HLB cartridges followed by LC-MS/MS measurement. ZEA, α-zearalenol, β-zearalenol, DON and de-epoxydeoxynivalenol (DOM) could be detected in the urine samples of the feeding trial. Thereby, DON was almost completely metabolised to DOM (83-98%) independent of the DON exposure. Moreover, conjugated toxins were the major urinary metabolites based on results of the analysis with β-glucuronidase treated and untreated samples. Furthermore, relationships between toxin intake and urinary toxin concentration could be established. In conclusion, increased urine toxin concentrations may hint on toxin exposure through the diets and thus the mycotoxins ZEA and DON and their detected metabolites could be used as biomarkers of exposure.

Measurement of sterigmatocystin concentrations in urine for monitoring the contamination of cattle feed

This study aimed (1) at determining the levels of the fungal toxin sterigmatocystin (STC) in the feed and urine of cattle and (2) at evaluating the effects of supplementing the feed with a mycotoxin adsorbent (MA) on STC concentrations in urine. Two herds of female Japanese Black cattle were used in this study. The cattle in each herd were fed a standard ration containing rice straw from different sources and a standard concentrate; two groups of cattle from each herd (n = six per group) received the commercial MA, mixed with the concentrate or given as top-dressing, whereas a third group received no supplement and served as control. Urine and feed samples were collected at various time points throughout the experiment. STC concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-TMS). STC concentrations in straw were higher in Herd 1 (range 0.15–0.24 mg/kg DM) than in Herd 2 (range <0.01–0.06 mg/kg DM). In Herd 1, STC concentrations in urine significantly declined 2 weeks after replacing the contaminated feed, whereas MA supplementation had no effect. In conclusion, mycotoxins in urine samples are useful biological markers for monitoring the systemic exposure of cattle to multiple mycotoxins, as well as evaluating the effectiveness of interventions.

Urinary zearalenone measured with ELISA as a biomarker of zearalenone exposure in pigs

The suitability to assess zearalenone (ZEA) exposure in pigs of a commercial ELISA kit for ZEA analysis in urine was tested. A daily dose of 0, 5, 10, 20 and 40 μg synthetic ZEA per kilogram BW was administered via the feed to four gilts per dose group, and after 3 and after 7 days of ZEA intake, urine samples were assayed with the ELISA which has a relative cross-reactivity of 42% with α-zearalenol. The concentration of urinary ZEA equivalents (ZEA plus 42% of α-zearalenol present) did not differ between day 4 and day 8 (P = 0.50) within each dose group. The urinary ZEA equivalent/creatinine ratio was tightly correlated with ZEA intake (r = 0.95). The urinary ZEA equivalent/creatinine values at 0 and 40 μg/kg BW were distinctly different from those of the intermediate dose levels, whereas there was some overlapping of the individual values at the dose levels 5, 10 and 20 μg/kg BW. The urinary ZEA equivalent/creatinine ratio can be used as a biomarker for ZEA exposure in pigs provided that urine samples of several animals receiving the same diet are assayed, either separately or after pooling.

Mycotoxin syndrome in dairy cattle: characterisation and intervention results

In daily practice, dairy cattle may be exposed to complex mixtures of mycotoxins originating from pre- and postharvest contamination of roughages, silage and concentrates. In particular silage has been identified as a source of different microbial toxins, which may impair animal health and productivity. The aim of the current study was to identify functional and descriptive biomarkers for the mouldy silage syndrome in dairy cattle. Such biomarkers should also serve as indicators of the beneficial effects of intervention strategies. In a field trial, a total of 87 cows from three different farms were enrolled in the study. From these animals blood samples were collected at three different time points and subjected to multiple biochemical analyses. Within this group, fine needle liver biopsies were obtained from 43 animals and subjected to biochemical analyses and targeted gene expression profiles. The measured parameters represent biomarkers of inflammation, oxidative stress, gluconeogenesis and lipids. In the affected animals, oxidative stress and a dysfunction in lipid metabolism were observed, marked by significantly decreased levels of glutathione peroxidase (GSH-Px) activity, glucose-6-phosphate-dehydrogenase (G6PD) concentrations and trolox equivalent antioxidant capacity (TEAC) and significantly increased concentrations of free cholesterol in plasma, together with a decreased activity of phospholipid transfer protein (PLTP) and lecithin-cholesterol acyltransferase (LCAT). When a glucomannan mycotoxin absorbent was added to the daily ration for a period of 8 weeks most of these biochemical markers gradually improved to normal levels, and body condition and milk yield improved. The obtained results contribute to the understanding of the pathophysiological changes associated with multiple mycotoxin exposure in dairy cows and allow a refined assessment of intervention strategies under field conditions.

Application of mycotoxin adsorbent to cattle feed contaminated with zearalenone: urinary zearalenone excretion and association with anti-Müllerian hormone

This study investigated (1) protective effects of a commercially available mycotoxin adsorbent (MA) and (2) endocrine effects of in vivo exposure to zearalenone (ZEA) in cattle. The sample included a Japanese Black female cattle herd (MYT herd) that displayed persistently high urinary ZEA concentrations. A second herd (NM herd) was used as a control. Three groups from each herd were assessed: MX (n=6; MA mixed with concentrate), TD (n=6; MA applied as topdressing with the concentrate), and a positive control (n=6; no MA application). Urine and blood samples were collected at the start of MA supplementation (day 0), on the final day of supplementation (day 16), and on the final day of the sampling period (day 58 for MYT herd and day 50 for NM herd). Urinary ZEA concentrations (pg/mg of creatinine) were measured by ELISA and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Haematological and serum biochemical analyses were performed to monitor hepatic, renal, nutritional, and mineral intake statuses. Ovulation status was assessed by progesterone (P4) and antral follicle population by anti-Müllerian hormone (AMH) levels. The urinary concentrations of ZEA and its metabolites in the MX and TD groups were significantly lower (P<0.05) at day 16 compared with the control group, as measured by LC-MS/MS. The valid ratio of AMH-positive (≯0.08 ng/ml) cattle was significantly higher in the NM herd than in the MYT herd without affecting the P4-positive (≯3 ng/ml) ratio, suggesting different populations of antral follicles. Significant differences were also observed between the MX and the control in aspartate aminotransferase and γ-glutamyltransferase at day 58, suggesting preventive effects of MA supplementation. Our field trial indicated that MA supplementation of a ZEA-contaminated diet has beneficial effects in reducing ZEA absorption from the intestine of cattle, maintaining endocrine homeostasis and reversing hepatic effects.

Developments in mycotoxin analysis: an update for 2011-2012

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2011 and mid- 2012. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. A section on mycotoxins in botanicals and spices is also included. Methods for mycotoxin determination continue to be developed using a wide range of analytical systems ranging from rapid immunochemical-based methods to the latest advances in mass spectrometry. This review follows the format of previous reviews in this series (i.e. sections on individual mycotoxins), but due to the rapid spread and developments in the field of multimycotoxin methods by liquid chromatography-tandem mass spectrometry, a separate section has been devoted to advances in this area of research.

Natural contamination of dietary rice straw with zearalenone and urinary zearalenone concentrations in a cattle herd

The present study was conducted to 1) identify the natural source of feed contamination by zearalenone (ZEN), which was suspected to have caused persistently increased urinary ZEN concentrations in one of our experimental cattle herds, and 2) evaluate the effects of intervention against this source of contamination. As an experimental model, a fattening Japanese Black cattle herd showing persistently increased urinary ZEN concentrations was identified. Urinary ZEN concentrations of cows fed with new rice straw (experimental group, n = 6) vs. cows that continued to feed on the old rice straw (control group, n = 4) were measured at the start (d 1) and at 2 wk (d 14) after the onset of feeding with straw. In addition, the ZEN concentration in feed and water samples was measured by using both the ELISA and HPLC methods. Furthermore, isolation and identification of fungi from rice straw and concentrate feed samples were performed. The urinary ZEN concentration [ZEN (pg/mL)/creatinine (mg/mL) = pg/mg of creatinine] of cows fed with new rice straw was significantly (P < 0.05) less (843 pg/mg of creatinine) than that of cows fed with old rice straw (15,951 pg/mg of creatinine). On both d 1 and 14, the ZEN concentrations of old rice straw were greater than those of new rice straw. In addition, fungal colonies were observed in the culture media that was obtained from the old rice straw suspected of ZEN contamination, but not in the culture media from new rice straw or other feed samples. In conclusion, our field trials clearly indicate that the rice straw fed to the cows was naturally contaminated with ZEN, and that the monitoring of urinary ZEN concentrations could prove to be a useful tool for detecting the exposure of cattle to ZEN contamination at the farm level.