o:1496 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 en 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. Feed Safety Multi-mycotoxin Analysis Dairy Farming Total Mixed Rations Maize Silage Phytoestrogens Co-occurrence 1552099 10.3390/toxins15020153 2023-04-13T12:20:27.157Z 44 yes 46 Felipe Penagos-Tabares University of Veterinary Medicine Vienna 0000-0002-4698-4741 Qendrim Zebeli University of Veterinary Medicine Vienna person 0000-0001-5188-9004 Michael Sulyok person 0000-0002-3302-0732 Rudolf Krska person 0000-0001-6843-9755 Johannes Faas person Juan-David Orozco person Luis Zavala person Ezequías Castillo-Lopez University of Veterinary Medicine Vienna person 0000-0002-9304-2351 César Garzón-Pérez person Samanta-Irais Flores-Quiroz person Juan-Ignacio Artavia person application/pdf 4896579 https://phaidra.vetmeduni.ac.at/o:1496 no yes 16 70 1552253 Toxins 26 15 2 MDPI 2023