**5. Conclusions**

In conclusion, this 3-year study has demonstrated the shifting mycotoxin load in silage maize fields at harvest due to changing weather conditions, possibly induced by climate change. Fumonisins, produced by *F. verticillioides*, which is more prevalent in tropical climates, were detected sporadically in Flanders in wet and cold years, but were found far more frequent during dry and hot years. Nivalenol was found in all but one of the samples, across all three years, making it the most stable and widespread mycotoxin. Concentrations went as high as 6776 μg/kg. Aflatoxins were not found, but *Aspergillus* spp. grow at similar conditions as *F. verticillioides*, so these mycotoxins should not be overlooked in future surveys. In order to monitor the e ffect of climate change on these changing weather conditions and on subsequent mycotoxin production, a yearly sampling should be continued.

The next step will be to identify the underlying cultivation, environmental and climatic factors that influence mycotoxin contamination in the field, and to create a prediction model for farmers based on these data. Ultimately, this research could help reduce mycotoxin contamination in silage maize and reduce mycotoxicosis in dairy cattle.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-2607/7/11/571/s1, Table S1: Results of the LC-MS/MS and qPCR analysis of 257 maize samples in Flanders in 2016-2018.

**Author Contributions:** Conceptualization, G.H., K.A. and S.C.; formal analysis, J.V.; investigation, J.V. and K.D.V.; methodology, S.D.S.; resources, S.D.S. and G.H.; data curation, J.V.; Writing—Original draft preparation, J.V.; Writing—Review and editing, K.A. and G.H.; visualization, J.V.; supervision, K.A. and G.H.; project administration, G.H.; funding acquisition, G.H. and S.C.

**Funding:** This research is part of the project 'Ontwikkeling van een beslissingsondersteunend adviessysteem voor een betere beheersing van mycotoxines in maïskuilen', funded by Flanders Innovation and Entrepreneurship (VLAIO) (140971).

**Acknowledgments:** The authors kindly thank the dairy farmers who participated in this study. They also thank Sofie Landschoot and Xiangrong Chen (UGent, Faculty of Bioscience Engineering) for help with the qPCR analysis, and Christ'l Detavernier, Marthe De Boevre and Mario Van de Velde (UGent, Faculty of Pharmaceutical Sciences) for help with the LC-MS/MS analysis.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
