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.

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.

Silage is one of the main feed components of ruminants around the world and can make up about 50-80% of the rations of dairy cows during the winter. The aim of this study was to evaluate the usability of oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) aqueous and ethanol extracts to improve the hygienic quality of perennial ryegrass, red clover and blue alfalfa silage samples and estimate their effect on mycotoxins concentrations. Under laboratory conditions, 63 silage samples (21 perennial ryegrass, 21 blue alfalfa, 21 red clover) were fermented with inserted aqueous and ethanol extracts of oregano and thyme and two commercial inoculants with mesophilic lactic acid bacteria. After 96 days of fermentation, in silage samples were established fermentation parameters, microbiological status and mycotoxins concentrations. It was determined that the best results for achieving hygienic quality of perennial ryegrass and red clover silage samples was by insertion of aqueous and ethanol extracts of oregano and thyme. In blue alfalfa samples, the best results of silage hygienic indicators were determined by inserting aqueous and ethanol extracts of oregano. Aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEA) and T-2 toxin concentrations in perennial ryegrass, red clover and blue alfalfa silage samples were best reduced by inserting aqueous and ethanol extracts of oregano and thyme. The present study shows that these extracts can be used to improve silage hygienic quality, reduce mycotoxins concentrations and thus ensure the wellness of cattle.

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.

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