González Jartín, Jesús MaríaFerreiroa Martínez, VanesaRodríguez Cañás, InésAlfonso Rancaño, María AmparoSáinz Oses, María JesúsAguín Casal, Olga MaríaRodríguez Vieytes, MercedesGomes, AnaRamos, IsabelBotana López, Luis Miguel2022-02-252022-02-252022International Journal of Food Microbiology 365 (2022) 1095560168-1605http://hdl.handle.net/10347/27618Maize and grass silages are important dietary components for ruminant livestock that influence the quality of animal products for human consumption, such as milk, in many parts of the world. Infection of plants by fungi able to produce mycotoxins, either in the field or post-harvest, can result in a decrease of silage nutritional quality and, consequently, in milk quality. In this study, 45 maize and grass silage samples were collected from 25 dairy farms located in the north of Portugal. The occurrence of fungi was evaluated in samples, the most frequently isolated species being Aspergillus fumigatus, Dipodascus geotrichum, Mucor circinelloides, Penicillium paneum, and Aspergillus flavus. The mycotoxigenic profile of the fungal species was studied using the ultra-high-performance liquid chromatography coupled to mass spectrometry–ion trap–time-of-flight (UHPLC–MS–IT–TOF) detection. In addition, a new method based on a QuEChERS extraction followed by the UHPLC- tandem mass spectrometry (UHPLC-MS/MS) detection was developed for simultaneous analysis of 39 mycotoxins in silage. A high co-occurrence of Fusarium mycotoxins was found, although at low levels of contamination. Deoxynivalenol and beauvericin were found in more than 82% of maize silage samples. It can be highlighted the low occurrence of Penicillium and Aspergillus toxins in the maize and grass silages studied despite the frequent detection of species of both generaeng© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Attribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/MycotoxinSilageQuEChERSUHPLC-MS/MSUHPLC–MS–IT–TOFjournal article10.1016/j.ijfoodmicro.2022.109556open access