Mycotoxins, Phytoestrogens and Other Secondary Metabolites in Austrian Pastures: Occurrences, Contamination Levels and Implications of Geo-Climatic Factors

Abstract

Pastures are key feed sources for dairy production and can be contaminated with several secondary metabolites from fungi and plants with toxic or endocrine-disrupting activities, which possess a risk for the health, reproduction and performance of cattle. This exploratory study aimed to determine the co-occurrences and concentrations of a wide range of mycotoxins, phytoestrogens and other secondary metabolites in grazing pastures. Representative samples of pastures were collected from 18 Austrian dairy farms (one sample per farm) between April to October 2019. After sample preparation (drying and milling) the pastures were subjected to multi-metabolite analysis using LC-MS/MS. In total, 68 metabolites were detected, including regulated zearalenone and deoxynivalenol (range: 2.16–138 and 107–505 μg/kg on a dry matter (DM) basis, respectively), modified (3-deoxynivalenol-glucoside, HT-2-glucoside) and emerging Fusarium mycotoxins (e.g., enniatins), ergot alkaloids and Alternaria metabolites along with phytoestrogens and other metabolites. Aflatoxins, fumonisins, T-2 toxin, HT-2 toxin and ochratoxins were not detected. Of the geo-climatic factors and botanical diversity investigated, the environment temperature (average of 2 pre-sampling months and the sampling month) was the most influential factor. The number of fungal metabolites linearly increased with increasing temperatures and temperatures exceeding 15 °C triggered an exponential increment in the concentrations of Fusarium and Alternaria metabolites and ergot alkaloids. In conclusion, even though the levels of regulated mycotoxins detected were below the EU guidance levels, the long-term exposure along with co-occurrence with modified and emerging mycotoxins might be an underestimated risk for grazing and forage-fed livestock. The one-year preliminary data points out a dominant effect of environmental temperature in the diversity and contamination level of fungal metabolites in pastures.

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

“…Interestingly, mycoestrogens (such as ZEN, alternariol (AOH), and their modified forms) and PEs (such as isoflavones) have synergistic effects [ 32 , 33 , 34 ], which must be considered in the context of a complete risk assessment on livestock reproductive performance [ 35 , 36 , 37 , 38 ]. Fungal and plant growth as well as concentrations of secondary metabolites in the dietary components and finally in the complete rations are influenced by multiple factors such as plant species/varieties, infecting/colonizing fungal species/varieties, climatic conditions, geography, parasitic/symbiotic interactions, use of pesticides, and other agricultural practices utilized [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. The most influential factors favouring mycotoxin contamination and PE production of feedstuffs and diets of dairy cows should be studied.…”

Occurrence of mycotoxins in pastures: A systematic review

“…in 100% of samples ranging from 20 to 1,549 µg/kg, and byPenagos-Tabares et al (2021) in 61% of samples containing 1-23.7 µg/kg. These are potentially toxic levels, since tolerance levels for this toxin have not been determined yet by the United States or EU.…”

“…There is little in vivo scientific evidence that unequivocally confirms mycotoxin effects on ruminant health and production. In relation to the meat production industry, while contemporary production systems are focused on genetic improvement for high productivity and the slaughter of younger animals, it is known that young, high-yielding animals have higher metabolic rate that make them more susceptible to mycotoxins, which may lead to greater accumulation of toxic metabolites in their products (Adegbeye et al, 2020;Gallo et al, 2015;Penagos-Tabares et al, 2021;Rodrigues, 2014;Skládanka et al, 2013;Vedovatto et al, 2020).…”

“…Beef cattle in some of these countries are almost all raised in pastures, and in dairy production, pastures are a significant part (or total) of the fodder provided to cattle. In general, there is less information on the occurrence of mycotoxins in pastures and conserved forage than in grains and cereals, which raises concern given the significant role of pastures in the beef and dairy industry (Dias-Filho, 2016;Gallo et al, 2015;Gott et al, 2017;Nichea et al, 2015;Penagos-Tabares et al, 2021;Reed and Moore, 2009;Štýbnarová et al, 2016). As pastures are important sources of ruminant fodder for meat and milk production, the analysis of mycotoxin occurrence in pastures is essential from the T-2 and HT-2, diacetoxyscirpenol (DAS), and type B (B-Trich) including deoxynivalenol (DON) and nivalenol (NIV); Penicillium, which produces OTA, CPA, citrinin (CIT), PAT, and rubratoxins (RT); Alternaria, which produces tenuazonic acid (TA) and alternariol (AOL); Claviceps and Neotyphodium, which produce Ergot alkaloids (EA) (Cimbalo et al, 2020;Gallo et al, 2015;Magnoli et al, 2019;Pereira et al, 2019).…”

Prioritization of Mycotoxins Based on Their Genotoxic Potential with an In Silico-In Vitro Strategy

“…The general population is widely exposed to mycotoxins, mainly through diet, as occurrence above a detectable level is considered to be up to 60–80% [ 4 ]. Furthermore, in the current context of climate change, mycotoxins might appear as an emerging risk [ 5 ], as new climate scenarios might modify the presence of regulated mycotoxins [ 6 ] but also might introduce emerging, and thus currently not regulated, forms [ 7 ]. In brief, there is a great diversity of mycotoxins that can contaminate food and feed, and therefore a variety of different toxicological effects to consider when prioritizing.…”