Distribution of moulds and mycotoxins in maize grain silage in the trench silo

Abstract

In this study the mycological and mycotoxicological contamination of maize silage samples collected from the bottom (BL), middle (ML) and top (TL) layer in the silage trench silo was studied. Mycological testing of the silage contamination showed the presence of five potential toxigenic fungi of the genera, Aspergillus, Fusarium, Mucor, Penicillium and Rhizopus with their total number ranging from 1 to 10 x 103 CFU g-1. Also, four mycotoxins were detected as followed, aflatoxin B1 (AFB1), zearalenone (ZON), deoxynivalenol (DON) and fumonisin B1 (FB1). Mycotoxins AFB1 and FB1 were detected as 100% positive in all the samples tested. An average concentration of AFB1 was 2.31 μg kg-1, 2.51 μg kg-1 and 2.81 μg kg-1 in BL, ML and TL respectively, while the concentration of FB1 was 1292.00 μg kg-1, 1298.00 μg kg-1 and 1902.00 μg kg-1 in BL, TL and ML respectively. Average concentration of toxin ZON in positive samples was 15.69 μg kg-1 in BL and 30.68 μg kg-1 in ML, while its presence in the samples taken from the top layer was not detected. An average concentration of DON toxin in positive samples were in the range of 41.71 μg kg-1 for TL, 79.20 μg kg-1 for ML, while it was 97.00 μg kg-1 for BL. There was no statistically significant correlation between moisture content and total number of moulds and concentrations of certain mycotoxins. However, statistically highly significant correlations between the total number of moulds and AFB1 concentration (r = 1.0), ZON (r = 0.99) and FB1 (r = 0.91) were established, while weak correlation was obtained in the case of DON and total mould counts (r = 0.54).

U radu je ispitivana mikološka i mikotoksikološka kontaminacija uzoraka silaže od zrna kukuruza sakupljenih iz donjeg (DS), srednjeg (SS) i gornjeg (GS) sloja silaže u silo-trenču. Mikološkim ispitivanjima kontaminacije silaže ustanovljeno je prisustvo pet potencijalno toksigenih rodova plesni, Aspergillus, Fusarium, Mucor, Penicillium i Rhizopus sa ukupnim brojem od 1-10 x 103 CFU g- 1. Takođe, detektovana su i četiri mikotoksina kao što su aflatoksin B1 (AFB1), zearalenon (ZON), deoksinivalenol (DON) i fumonizin B1 (FB1). Mikotoksini AFB1 i FB1 detektovani su kao 100% pozitivni u svim ispitivanim uzorcima. Prosečna koncentracija AFB1 bila je 2,31 μg kg-1 za GS, 2,51 μg kg-1 za DS i 2,81 μg kg-1 za SS, dok je prosečna koncentracija FB1 bila 1292,00 μg kg-1 za DS, 1298,00 μg kg-1 za GS i 1902,00 μg kg-1 za SS. Prosečna koncentracija ZON toksina u pozitivnim uzorcima je 15,69 μg kg-1 za DS i 30,68 μg kg-1 za SS, dok njegovo prisustvo nije detektovano u uzorcima iz gornjeg sloja. Prosečna koncentracija DON toksina u pozitivnim uzorcima bila je od 41,71 μg kg-1 za GS, 79,20 μg kg-1 za SS do 97,00 μg kg-1 za DS. Nije utvrđena statistički značajna korelacija sardžaja vlage sa ukupnim brojem plesni i koncentracijom pojedinih mikotoksina. Međutim, utvrđena je statistički veoma značajna korelacija između ukupnog broja plesni i koncentracije AFB1 (r = 1,0), ZON (r = 0,99) i FB1 (r = 0,91), a nešto manja u slučaju DON i ukupnog broja plesni (r = 0,54).