Abstract Silages constitute a major component of the feed ration for dairy cows, being a potential source of mycotoxins due to the possible contamination by filamentous fungi capable of producing these toxic compounds. In this study, samples of different kinds of silages collected from farms located in four regions of Spain, were analysed to evaluate the occurrence of aflatoxins (AFs) and Fusarium mycotoxins. Lactic acid bacteria and fungal populations as well as pH and water activity were also studied. Penicillium, Geotrichum and Monascus were the main fungi identified in all the silages examined. The incidence of AFs was low (10 % of positive samples). Fusarium mycotoxins were detected in 40 % of the samples and fumonisins (FBs) were the most commonly detected. Maize silage was the most heavily contaminated type of silage. Levels of mycotoxins detected in positive samples did not exceed the EU guidance values. The lack of relationship between Fusarium counts and its mycotoxin concentrations suggested that mycotoxin production possibly occurred pre-ensiling or immediately post-ensiling. Outcomes showed that mould growth and mycotoxin contamination in silages should be regularly monitored in order to minimize the exposure of dairy cows to contaminated feed.

中文翻译：

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西班牙奶牛不同类型青贮饲料中的霉菌毒素和真菌种群

摘要 青贮饲料是奶牛日粮的主要成分，由于可能被能够产生这些有毒化合物的丝状真菌污染，因此它是霉菌毒素的潜在来源。在这项研究中，分析了从位于西班牙四个地区的农场收集的不同种类的青贮饲料样本，以评估黄曲霉毒素 (AF) 和镰刀菌毒素的发生情况。还研究了乳酸菌和真菌种群以及 pH 值和水分活度。青霉菌、地霉和红曲霉是所有青贮饲料中鉴定出的主要真菌。AF 的发生率很低（阳性样本的 10%）。在 40% 的样品中检测到镰刀菌真菌毒素，伏马菌素 (FB) 是最常检测到的。玉米青贮是污染最严重的青贮类型。在阳性样品中检测到的霉菌毒素水平没有超过欧盟指导值。镰刀菌计数与其霉菌毒素浓度之间缺乏相关性表明霉菌毒素的产生可能发生在青贮前或青贮后立即发生。结果表明，应定期监测青贮饲料中的霉菌生长和霉菌毒素污染，以尽量减少奶牛接触受污染饲料的机会。