After oral contamination, zearalenone (ZEN) is rapidly absorbed in organisms and can be detected in biological fluids. In this study, we investigated the metabolites of ZEN in the biological fluids of cows (blood, urine, milk). The study was divided into three stages: preparation (the first stage), investigation (the second stage), and final stage (the third stage). Samples of biological fluids were taken 7, 21, and 35 days after the beginning of the study. At the first stage and at the second stage, the cows were fed a total mixed ration (TMR) with naturally contaminated mycotoxin-zearalenone (500 ± 75 µg/kg). In the third stage, the cows were fed a TMR without mycotoxins. This study established that at the second stage, the alpha-zearalenol concentrations in the serum increased by 92% and the beta-zearalanol in the urine decreased by 48% compared to the first stage (p < 0.05). The beta-zearalenol and zearalanone concentrations in the urine were higher compared to that of the alpha-zearalenol. The zearalenone concentration in the milk at the second stage was 35% higher than at the first stage (p < 0.05). A significant negative correlation (r = –0.540) was determined between the beta-zearalenol and beta-zearalanol concentrations in the urine and the positive significant correlation (r = 0.826) between the beta-zearalanol and alpha-zearalenol concentrations in the serum (p < 0.05). During the study, it was determined that feeding cows for two weeks with a TMR without mycotoxins can reduce concentrations of alpha-zearalanol, beta-zearalenol, and beta-zearalanol in the biological fluids and can reduce the concentrations of ZEN in the milk, but does not reduce the concentration of zearalanone.

In this study, 119 samples of total mixed rations and different types of ensiled forage (maize and grass silage, and haylage) collected in 2019–2020 from dairy farms in Lithuania were analyzed to evaluate the quantitative occurrence of mycotoxins and endotoxins. Samples were analyzed using high-performance liquid chromatography (HPLC) with a fluorescent (FLD) and an ultraviolet detector (UV) of mycotoxins and a detection assay based on the ELISA technology for endotoxins. The study included toxins regulated within the European Union (aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON) and T-2 toxin) and nonregulated toxins (endotoxins). Mycotoxin analysis showed that 49.58% of the samples out of 119 were positive for AFB1, 52.11% for ZEA and DON, 55.47% for T-2 toxin and 84.04% for endotoxins. In the contaminated samples, the highest mean values of AFB1 and T-2 toxin were determined in the grass silage samples, while ZEA and DON–were determined in the maize silage samples. Maize silage samples had the highest ZEA and DON concentrations, exceeding the EU maximum permissible concentration limits. In the haylage samples, AFB1 mycotoxin exceeded the maximum concentration limits. The highest mean value of endotoxins was determined in the total mixed rations samples. This is the first study to provide information about the concentrations of mycotoxins and endotoxins in total mixed rations and different types of ensiled forages for dairy cows in Lithuania.

The aim of this study was to assess the usefulness of oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) extracts to decrease mycotoxin contents and improve the hygienic quality of maize (Zea mays L.) silage. Under laboratory conditions, maize silage samples were fermented with oregano (OE), thyme (TE), oregano and thyme mixture (MIX), and two commercial inoculants. After 90 days of fermentation, silos were opened and silage samples were taken for evaluation of mycotoxin concentrations and for hygienic quality analysis: assessment of fermentation parameters, the content of biogenic amines, and microbiological status. It was determined that the mycotoxin concentrations decreased differentially: ochratoxin A concentration was below the detection limit after treatment with the TE and MIX extracts, the lowest zearalenone and deoxynivalenol concentrations were achieved with the OE extract treatment, T-2 toxin concentration was significantly lower after treatment with the TE extract, and HT-2 toxin concentration was lower after treatment with the MIX extract. The lowest content of biogenic amines in maize silage was established with the MIX extract. Concerning the silage hygienic quality, the best results of fermentation parameters and microbiological status were also achieved with the MIX extract. The present study indicated that oregano and thyme herbal plant extracts can be used to decrease mycotoxin concentrations and improve the hygienic quality of maize silage.

The aim of this study was to estimate maize silage hygienic sanitary parameters, contamination with mycotoxins in dairy farms in Lithuania. In 2011–2012 maize silage samples were collected from 20 dairy farms: prior to ensiling and 3 and 8 months after ensiling. In maize samples, prior to ensiling, L. monocytogenes was detected 25.0 % and after 3 months of ensiling – 10 %. Average of yeast and filamentous fungi in raw material samples were respectively – 71.39 ± 32.17 and 47.67 ± 18.31 CFU/g, after 3 months – 50.06 ± 16.09 CFU/g and 28.27 ± 13.18, after 8 months – 213.81 ± 55.98 and 215.08 ± 56.16 CFU/g. In raw maize dominated Fusarium spp. and in silage – Aspergillus, Penicillium spp. Average of lactic acid bacteria – 189.01 ± 57.79 (3 months after ensilage) and 436.11 ± 93.97 CFU/g (8 months after ensilage). Compared prior to ensilage and 3 and 8 months after ensilage maize samples, higher mycotoxins concentrations of DON – 36.96 % (P < 0.05) and ZEA – 77.32 % (P < 0.05) were detected in 3 month after ensilage, T-2 toxin – 72.69 % (P < 0.05), AFL – 94.31 % (P < 0.05) were detected in 8 month after ensilage. Concentration of OTA was higher 34.99 % (P > 0.05) in samples after 3 months of ensiling. Dry matter and pH respectively: prior to ensiling – 36.96 % and 5.26, 3 months after ensiling – 33.17 % and 3.84, 8 months after ensiling – 40.52 % and 3.91. The current results indicate the presence of yeast, viable fungi spores and mycotoxins AFL (total), ZEA, DON, T-2 and OTA contamination in maize silage in Lithuania. Keywords: fungi, maize silage, mycotoxin, yeast.