ABSTRACT Silage is susceptible to fungal contamination, which can reduce its nutritional value and produce harmful mycotoxins. The aim of this study was to analyse the dynamics of toxigenic fungi in silage before and after fermentation of forage biomass and their correlation with the mycotoxins detected. A total of 243 samples of green forage and silage were collected from 27 dairy farm silos at harvest (P1) and after 60 (P2) and 100 days (P3) of fermentation. Samples were taken from the top, middle and bottom of the silo and mixed to obtain representative samples of the whole silo. Fungal identification was based on macroscopic and microscopic characteristics, while mycotoxin analysis used QuEChERS extraction followed by GC–MS/MS and LC–MS/MS analysis. The study revealed differences ( p < 0.05) in fungal colony forming unit counts between silos and genera over the three sampling periods, with 40% of samples exceeding the safe fungal level (10,000 CFU/g). Fusarium sp., Penicillium sp., Aspergillus sp., Verticillium sp. and Cladosporium sp. were the dominant genera. Significant changes in fungal dynamics occurred before and after biomass fermentation. Of the 26 mycotoxins tested, Fusarium ‐related mycotoxins such as deoxynivalenol, HT‐2 toxin, enniatin A1, enniatin B, enniatin B1, beauvericin and tentoxin were detected at varying concentrations. Principal component analysis revealed temporal changes in fungal and mycotoxin profiles, with Fusarium colony forming unit positively correlating with deoxynivalenol and HT‐2 toxin in P1; deoxynivalenol, enniatin B, tentoxin, beauvericin and zearalenone in P2; and deoxynivalenol and enniatin B in P3. The results highlight the need for continuous silage monitoring to control fungal and mycotoxin contamination and to ensure feed safety.
Mannai et al. (Thu,) studied this question.