Cocktails of Mycotoxins, Phytoestrogens, and Other Secondary Metabolites in Diets of Dairy Cows in Austria: Inferences from Diet Composition and Geo-Climatic Factors

First Results on the Presence of Mycotoxins in the Liver of Pregnant Fallow Deer (Dama dama) Hinds and Fetuses

Reproductive abnormalities have been observed in fallow deer populations in Hungary. We supposed mycotoxin contamination to be one of the possible causes because multi-mycotoxin contamination is known to be dangerous even at low toxin levels, especially for young animals. We investigated the spatial pattern of mycotoxin occurrences and the relationship between maternal and fetal mycotoxin levels. A total of 72 fallow deer embryos and their mothers were sampled in seven forested regions in Hungary in the 2020/2021 hunting season. We analyzed Aflatoxin (AF), Zearalenone (ZEA), Fumonizin B1 (FB1), DON, and T2-toxin concentrations in maternal and fetal livers by ELISA. AF was present in 70% and 82%, ZEA in 41% and 96%, DON in 90% and 98%, T2-toxin in 96% and 85%, and FB1 in 84% and 3% of hind and fetus livers, respectively. All mycotoxins passed into the fetus, but only Fumonizin B1 rarely passed. The individual variability of mycotoxin levels was extremely high, but the spatial differences were moderate. We could not prove a relation between the maternal and fetal mycotoxin concentrations, but we found an accumulation of ZEA and DON in the fetuses. These results reflect the possible threats of mycotoxins to the population dynamics and reproduction of wild fallow deer.

Mycotoxins evaluation of total mixed ration (TMR) in bovine dairy farms: An update

The total mixed ration (TMR) is currently a widespread method to feed dairy cows. It is a mixture of raw fodder and concentrate feed that can be contaminated by several mycotoxins. The main aim of this paper was to provide a critical review on TMR mycotoxin occurrence and its usefulness to monitor and control them on-farm. Aflatoxins, zearalenone, deoxynivalenol, T-2 toxin and fumonisins (regulated mycotoxins) are the most prevalent mycotoxins evaluated in TMR. Nonetheless, several emerging mycotoxins represent a health risk at the animal level regarding their prevalence and level in TMR. Even when measured at low levels, the co-occurrence of mycotoxins is frequent and synergistic effects on animal health are still underevaluated. Similar to the animal feed industry, on-farm plans monitoring mycotoxin feed contamination can be developed as a herd health management program. The estimated daily intake of mycotoxins should be implemented, but thresholds for each mycotoxin are not currently defined in dairy farms.

A 2-year study reveals implications of feeding management and exposure to mycotoxins on udder health, performance, and fertility in dairy herds

We recently reported the ubiquitous occurrence of mycotoxins and their secondary metabolites in dairy rations and a substantial variation in the feeding management among Austrian dairy farms. The present study aimed to characterize to which extent these factors contribute to the fertility, udder health traits, and performance of dairy herds. During 2019 and 2020, we surveyed 100 dairy farms, visiting each farm 2 times and collecting data and feed samples. Data collection involved information on the main feed ingredients, nutrient composition, and the levels of mycotoxin and other metabolites in the diet. The annual fertility and milk data of the herds were obtained from the national reporting agency. Calving interval was the target criterion for fertility performance, whereas the percentage of primiparous and multiparous cows in the herd with somatic cell counts above 200,000 cells/mL was the criterion for impaired udder health. For each criterion, herds were classified into 3 groups: high/long, mid, and low/short, with the cut-off corresponding to the <25th and >75th percentiles and the rest of the data, respectively. Accordingly, for the calving interval, the cut-offs for the long and short groups were ≥400 and ≤380 d, for the udder health in primiparous cows were ≥20% and ≤8% of the herd, and for the udder health in multiparous cows were ≥35% and ≤20% of the herd, respectively. Quantitative approaches were further performed to define potential risk factors in the herds. The high somatic cell count group had higher dietary exposure to enniatins (2.8 vs. 1.62 mg/cow per d), deoxynivalenol (4.91 vs. 2.3 mg/cow per d), culmorin (9.48 vs. 5.72 mg/cow per d), beauvericin (0.32 vs. 0.18 mg/cow per d), and siccanol (13.3 vs. 5.15 mg/cow per d), and total Fusarium metabolites (42.8 vs. 23.2 mg/cow per d) and used more corn silage in the ration (26.9% vs. 17.3% diet DM) compared with the low counterparts. Beauvericin was the most substantial contributing variable among the Fusarium metabolites, as indicated by logistic regression and modeling analyses. Logistic analysis indicated that herds with high proportions of cows with milk fat-to-protein ratio >1.5 had an increased odds for a longer calving interval, which was found to be significant for primiparous cows (odds ratio = 5.5, 95% confidence interval = 1.65-21.7). As well, herds with high proportions of multiparous cows showing levels of milk urea nitrogen >30 mg/dL had an increased odds for longer calving intervals (odds ratio = 2.96, 95% confidence interval = 1.22-7.87). In conclusion, the present findings suggest that dietary contamination of Fusarium mycotoxins (especially emerging ones), likely due to increased use of corn silage in the diet, seems to be a risk factor for impairing the udder health of primiparous cows. Mismatching dietary energy and protein supply of multiparous cows contributed to reduced herd fertility performance.

Risks for animal health related to the presence of ergot alkaloids in feed

The European Commission requested EFSA to provide an update of the 2012 Scientific Opinion of the Panel on Contaminants in the Food Chain (CONTAM) on the risks for animal health related to the presence of ergot alkaloids (EAs) in feed. EAs are produced by several fungi of the Claviceps and Epichloë genera. This Opinion focussed on the 14 EAs produced by C. purpurea (ergocristine, ergotamine, ergocornine, α- and β-ergocryptine, ergometrine, ergosine and their corresponding 'inine' epimers). Effects observed with EAs from C. africana (mainly dihydroergosine) and Epichloë (ergovaline/-inine) were also evaluated. There is limited information on toxicokinetics in food and non-food producing animals. However, transfer from feed to food of animal origin is negligible. The major effects of EAs are related to vasoconstriction and are exaggerated during extreme temperatures. In addition, EAs cause a decrease in prolactin, resulting in a reduced milk production. Based on the sum of the EAs, the Panel considered the following as Reference Points (RPs) in complete feed for adverse animal health effects: for pigs and piglets 0.6 mg/kg, for chickens for fattening and hens 2.1 and 3.7 mg/kg, respectively, for ducks 0.2 mg/kg, bovines 0.1 mg/kg and sheep 0.3 mg/kg. A total of 19,023 analytical results on EAs (only from C. purpurea) in feed materials and compound feeds were available for the exposure assessment (1580 samples). Dietary exposure was assessed using two feeding scenarios (model diets and compound feeds). Risk characterisation was done for the animals for which an RP could be identified. The CONTAM Panel considers that, based on exposure from model diets, the presence of EAs in feed raises a health concern in piglets, pigs for fattening, sows and bovines, while for chickens for fattening, laying hens, ducks, ovines and caprines, the health concern related to EAs in feed is low.

Changes in the nutrient profile and the load of mycotoxins, phytoestrogens, and pesticides in horse pastures during spring and summer in Austria

Pastures are used for grazing and the production of conserved roughage in horses. Yet, the nutritional profile of the forage varies from spring to late summer, affecting equine nutrient supply and health. In addition, environmental factors may also favor plant contaminants such as mycotoxins. This study aimed to determine the nutritional profile and contaminant load of selected horse pastures from early spring till late summer. The nutrient composition (main macronutrients, macro elements and trace elements), as well as mycotoxins, metabolites, pesticides, and plant-derived compounds of seven horse pastures were analyzed. Each pasture was sampled three times and the samples were categorized according to the status of the pasture plants: ear emergence, early- till full bloom, and drought-damaged vegetation. Drought-damaged pastures demonstrated a rise in the acid to neutral detergent fiber ratio, calcium, iron, and magnesium but lower potassium contents. Mycotoxins and other contaminants were found in the pastures including 64 fungal compounds (ergot alkaloids (13) and metabolites from Fusarium (21), Aspergillus (2), Penicillium (8), Alternaria (8) and other fungal species (12), one bacterial metabolite (cereulide), twelve plant metabolites (including eight phytoestrogens and three cyanogenic glycosides (linamarin, lotaustralin and prunasin)), 11 nonspecific metabolites and six pesticides. Fusarium metabolites showed the highest concentrations among the fungal metabolites and drought-induced stress increased the contamination levels (range: 123-3873 µg/kg DM). In conclusion, there was a dominant effect of the developmental stages of the plants, botanical composition of the pastures and weather conditions on the nutritional composition and presence of contaminants on pastures.

Co-occurrence of mycotoxins and other fungal metabolites in total mixed rations of cows from dairy farms in Punjab, Pakistan

After India and the USA, Pakistan is the third country leading in global dairy production, a sector of very high socioeconomic relevance in Asia. Mycotoxins can affect animal health, reproduction and productivity. This study analysed a broad range of co-occurring mycotoxins and fungal secondary metabolites derived from Alternaria, Aspergillus, Fusarium, Penicillium and other fungal species. To complete this, a validated multi-metabolite liquid chromatography/electrospray ionization-tandem mass spectrometric (LC/ESI-MS/MS) method was employed, detecting 96 of > 500 tested secondary fungal metabolites. This first preliminary study demonstrated that total mixed rations (TMRs) (n = 30) from big commercial dairy cattle farms (> 200 lactating cows) in Punjab, Pakistan, presented ubiquitous contamination with mixtures of mycotoxins. The mean of mycotoxins per sample was 14, ranging from 11 to 20 mycotoxins among all TMR samples. Metabolites derived from other fungi and Fusarium spp. showed the highest levels, frequency and diversity among the detected fungal compounds. Among the most prevalent mycotoxins were Fusarium toxins like fumonisins B1 (FB1) (93%), B2 (FB2) (100%) and B3 (FB3) (77%) and others. Aflatoxin B1 (AFB1) was evidenced in 40% of the samples, and 7% exceeded the EU maximum limit for feeding dairy cattle (5 µg/kg at 88% dry matter). No other mycotoxin exceeds the EU guidance values (GVs). Additionally, we found that dietary ingredients like corn grain, soybean meal and canola meal were related to increased contamination of some mycotoxins (like FB1, FB2 and FB3) in TMR from the province of Punjab, Pakistan. Among typical forage sources, the content of maize silage was ubiquitous. Individually, the detected mycotoxins represented relatively low levels. However, under a realistic scenario, long-term exposure to multiple mycotoxins and other fungal secondary metabolites can exert unpredictable effects on animal health, reproduction and productivity. Except for ergot alkaloids (73%), all the groups of metabolites (i.e. derived from Alternaria spp., Aspergillus spp., Fusarium spp., Penicillium spp. and other fungi) occurred in 100% of the TMR samples. At individual levels, no other mycotoxins than AFB1 represented a considerable risk; however, the high levels of co-occurrence with several mycotoxins/metabolites suggest that long-term exposure should be considered because of their potential toxicological interactions (additive or synergistic effects).

Mixtures of Mycotoxins, Phytoestrogens, and Other Secondary Metabolites in Whole-Plant Corn Silages and Total Mixed Rations of Dairy Farms in Central and Northern Mexico

Mycotoxins and endocrine disruptors such as phytoestrogens can affect cattle health, reproduction, and productivity. Most studies of mycotoxins in dairy feeds in Mexico and worldwide have been focused on a few (regulated) mycotoxins. In contrast, less known fungal toxins, phytoestrogens, and other metabolites have been neglected and underestimated. This study analyzed a broad spectrum (>800) of mycotoxins, phytoestrogens, and fungal, plant, and unspecific secondary metabolites in whole-plant corn silages (WPCSs) and total mixed rations (TMRs) collected from 19 Mexican dairy farms. A validated multi-metabolite liquid chromatography/electrospray ionization-tandem mass spectrometric (LC/ESI-MS/MS) method was used. Our results revealed 125 of >800 tested (potentially toxic) secondary metabolites. WPCSs/TMRs in Mexico presented ubiquitous contamination with mycotoxins, phytoestrogens, and other metabolites. The average number of mycotoxins per TMR was 24, ranging from 9 to 31. Fusarium-derived secondary metabolites showed the highest frequencies, concentrations, and diversity among the detected fungal compounds. The most frequently detected mycotoxins in TMRs were zearalenone (ZEN) (100%), fumonisin B1 (FB1) (84%), and deoxynivalenol (84%). Aflatoxin B1 (AFB1) and ochratoxin A (OTA), previously reported in Mexico, were not detected. All TMR samples tested positive for phytoestrogens. Among the investigated dietary ingredients, corn stover, sorghum silage, and concentrate proportions were the most correlated with levels of total mycotoxins, fumonisins (Fs), and ergot alkaloids, respectively.

Residues of pesticides and veterinary drugs in diets of dairy cattle from conventional and organic farms in Austria

Modern agriculture depends highly on pesticides and pharmaceutical preparations, so controlling exposure to these substances in the feed and food chain is essential. This article presents the first study on residues of a broad spectrum of pesticides and veterinary drugs in the diets of dairy cattle. One hundred and two representative samples of the complete diets, including basal feed rations and additional fed concentrate, were collected in three Austrian provinces (Styria, Lower and Upper Austria) in 2019 and 2020. The samples were tested for >700 pesticides, veterinary drugs and related metabolites using a validated method based on liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). In total, 16 residues (13 pesticides and three veterinary drug residues) were detected. > 90% of the diets contained pesticide residues and <10% veterinary drug residues, whereas banned pesticides were not found. The most frequent pesticide residues were fluopyram (62%), piperonyl butoxide (39%) and diethyltoluamide (35%). The following pesticides exceed the default EU maximum residue level (MRL) (10 μg kg^-1) for products exclusively used for animal feed production: Benzovindiflupyr (proportion of samples > MRLs: 1%), bixafen (2%), fluopyram (6%), ipconazole (1%) and tebuconazole (3%). Three residues (dinitrocarbanilide, monensin and nicarbazin) of veterinary drugs were identified, all below the MRLs. Over 60% of the evaluated samples contained mixtures of two to six residues/sample. Only one pesticide (diethyltoluamide) presented a significant difference among regions, with higher concentrations in Upper Austria. Brewery's spent grains were the dietary ingredient that showed the strongest correlation to pesticide residues. These findings evidence the realistic scenario of highly occurrent low doses of pesticides cocktails in the feed/food chain, which may affect the animal, human and environmental health. Since the risk assessments are based on single pesticides, the potential synergistic effect of co-occurring chemicals ("cocktail effect") requires further investigations.