B. Bakutis, E. Monstviliene, G. Januskeviciene: Analyses of Airborne Contamination with Bacteria, Endotoxins and Dust in Livestock Barns and Poultry Houses. Acta Vet. Brno 2004, 73: 283-289. In the air of livestock houses different amounts of microorganisms are present along with dust. The aim of this study was to compare results of quantitative analyses of airborne bacteria, endotoxins and dust in livestock and poultry houses. In insulated cowsheds for dairy cows the average amount of microorganisms and gram-negative bacteria were higher than in uninsulated cowsheds (p < 0.01). Average amounts of microorganisms and gram-negative bacteria in pig and poultry houses were higher than in insulated and uninsulated cowsheds (p < 0.01), and the air of pig and poultry houses was more contaminated with endotoxins than that of insulated and uninsulated cowsheds (p < 0.01). In insulated cowsheds the concentration of dust was higher than in uninsulated cowsheds (p < 0.01). In pig and poultry houses the concentration of dust was higher than in insulated and uninsulated cowsheds (p < 0.01). We detected a close connection among the amount of dust and airborne bacteria and their endotoxins in air of livestock and poultry houses. There is a need for further reducing the emission of environmentally harmful substances. Precise data of this type are of importance for licensing new animal farms as well as residential areas in the farming environment.

One hundred two samples of feeds made in Lithuania, which included maize silage, grass-legume silage, hay and ensiled crimped maize were investigated during 2008-2012 for contamination with some mycotoxins. The highest concentrations of mycotoxins determined were those of deoxynivalenol (DON) -471.0 μg/kg and aflatoxin B 1 (AFB 1 ) -21.2 μg/kg in ryegrass silage from bales, and zearalenone (ZEA) -625.0 μg/kg in maize silage from trenches. The present study has been carried out based on these data because animal feeds contaminated with mycotoxins can cause reduced productivity of dairy cows and health disorders in the long term. The aim of this study was to investigate the long-term exposure of toxic effects of a diet naturally contaminated with low concentrations of mycotoxins on milk composition and biochemical, hematological, immunological parameters of dairy cows and to determine the anti-mycotoxin effect of Mycofix Plus 3.E. Twenty eight clinically healthy, medium productive Lithuanian Red cows were selected. ZEA was a major contaminant found in the corn silage at concentration levels of up to 1000.0 μg/kg of dry matter. DON was the second major found in the hay at concentration levels of up to 600.0 μg/kg of dry matter. The highest concentration AFB 1 -10.0 μg/kg was determined in ground barley. The Anti-Mycotoxin Additive (AMA) Mycofix Plus 3.E was given individually to 14 cows at a concentration of 40.0 g daily for 9 weeks.The present results indicate that feeds naturally contaminated with low concentration of mycotoxins produced by Fusarium spp. and Aspergillus spp. in a diet of dairy cows can have a negative influence on somatic cell count, blood parameters and immunity. The addition of an Anti-Mycotoxin Additive (Mycofix Plus 3.E) to diet of dairy cows can prevent many of these effects.

The aim of this study was to apply the enzymatic treatment and fermentation by Pediococcus acidilactici BaltBio01 strain for industrial cereal by-products conversion to food/feed bioproducts with high amount of probiotic lactic acid bacteria (LAB). LAB propagated in potato media and spray-dried remained viable during 12 months (7.0 log cfu/g) of storage and was used as a starter for cereal by-products fermentation. The changes of microbial profile, biogenic amines (BAs), mycotoxins, lactic acid (L/D), lignans and alkylresorcinols (ARs) contents in fermented cereal by-product were analysed. Cereal by-products enzymatic hydrolysis before fermentation allows to obtain a higher count of LAB during fermentation. Fermentation with P. acidilactici reduce mycotoxins content in fermented cereal by-products. According to our results, P. acidilactici multiplied in potato juice could be used for cereal by-products fermentation, as a potential source to produce safer food/feed bioproduct with high amount of probiotic LAB for industrial production.

Stable isotope analysis was applied to describe the poultry house environment. The poultry house indoor environment was selected for this study due to the relevant health problems in animals and their caretakers. Air quality parameters including temperature, relative humidity, airflow rate, NH, CO and total suspended particles, as well as mean levels of total airborne bacteria and fungi count, were measured. Carbon isotope ratios (C/C) were obtained in size-segregated aerosol particles. The carbon (C/C) and nitrogen (N/N) isotope ratios were measured in feed, litter, scrapings from the ventilation system, feathers and eggs. Additionally, the distribution of δC and δN values in different tissues of the chicken was examined. The airborne bacteria and fungi extracted from the air filters collected from poultry farms were grown in the laboratory in media with known isotope values and measured for stable isotope ratios. Analysis of isotope fractionation between microorganisms and their media indicated the applicability of stable isotope analysis in bulk samples for the identification of source material. The analysed examples imply that stable isotope analysis can be used to examine the indoor environment along with its biology and ecology, and serve as an informative bioanalytical tool.

The aim of the study was to evaluate the antimicrobial effects of essential oils in vitro for a possible application to reduce the content of microorganisms in the air of animal farms. The essential oils Mentha arvensis L. and Zingiber officinale R. were screened against bacteria Staphylococcus aureus Rosenbach, Enterococcus faecium Schleifer and Kilpper-Bälz, Pseudomonas aeruginosa Migula, Escherichia coli Castellani and Chalmers, Proteus mirabilis Hauser and yeast Candida albicans Berkhout. The minimal inhibitory concentrations of the active essential oils were tested using broth dilution assay at concentrations ranging from 0.1-50.0%. The oils showed a wide spectrum of antibacterial activity: concentrations of 0.1-0.8% of Mentha arvensis L. reduced the total bacterial counts of Proteus mirabilis Hauser and Candida albicans Berkhout. The dilution method revealed that essential oil Zingiber officinale R. only at high bacteriocidal concentrations was able to stop the bacterial growth. Zingiber officinale R. at 50.0% completely inhibited the growth of Staphylococcus aureus Rosenbach, Enterococcus faecium Schleifer and Kilpper-Bälz, Pseudomonas aeruginosa Migula, Escherichia coli Castellani and Chalmers, Proteus mirabilis Hauser and yeast Candida albicans Berkhout.

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 the current study was to investigate biogenic amines and mycotoxins concentrations in baled silage (mainly Poaceae family grasses) prepared in organic and conventional farms and to relate these parameters to fermentative parameters. The mean dry matter (DM) content was 364.10±93.31 and 424.70±95.93g/kg in the silage from organic and conventional farms respectively. The silage samples from organic farms had 17.00% higher (P≤ 0.05) tyramine (TY) than the silage from conventional farms. Conventional farm samples were characterized by 46.00% higher histamine (HIS) (P≤ 0.05), 9.80% higher putrescine (PUT) (P≤ 0.05), 17.30% higher cadaverine (CAD) (P≤ 0.05). Aflatoxins (AFL) (total) and zearalenone (ZEN), T-2/HT-2 concentrations were higher respectively 16.00% (P≤ 0.05) and 13.40% (P≤ 0.05), 1.80% (P≤ 0.05) in the silage prepared in organic farms. Deoxynivalenol (DON) concentration was higher 42.40% (P≤ 0.05) in silage from conventional farms. Volatile fatty acids (VFA), lactic acid, ethanol, pH and ammonia nitrogen showed that the silage samples from organic and conventional farms were of good quality. Our study suggests differences in biogenic amine formation or mycotoxins content in silage from organic and conventional farming, but, overall, the measured values are too low to be relevant for animal health. Furthermore, these differences might as well be due to the difference in dry matter content and plant maturity between the organic and conventional silage samples.Keywords: biogenic amines, mycotoxins, volatile fatty acids, organic farm, conventional farm RESUMO O objetivo do presente estudo foi investigar concentrações de aminas biogênicas micotoxinas em silagem embalada (principalmente gramíneas da família Poaceae) preparada em fazendas orgânicas e convencionais e relacionar esses parâmetros a parâmetros fermentativos. A massa seca média (MS) foi 364,10±93,31 e 424,70±95,93g/kg na silagem de fazendas orgânicas e convencionais, respectivamente. As amostras de silagem de fazendas orgânicas tinham 17% a mais de tyramina (TY) (p≤ 0,05) que as de fazendas convencionais. As amostras de fazendas convencionais foram caracterizadas por histamina (HIS) 46,00% mais alta (P≤ 0,05), 9,80% putrecina (PUT) mais alta (P≤ 0,05), 17,30% de cadaverina (CAD) mais alta (P≤ 0,05). Aflatoxnas (AFL) (total) e zearalenone (ZEN), T-2/HT-2 tinham concentrações mais altas em respectivamente

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