Jiri Skladanka

How Do Grass Species, Season and Ensiling Influence Mycotoxin Content in Forage?

Mycotoxins are secondary metabolites produced by fungal species that have harmful effects on mammals. The aim of this study was to assess the content of mycotoxins in fresh-cut material of selected forage grass species both during and at the end of the growing season. We further assessed mycotoxin content in subsequently produced first-cutting silages with respect to the species used in this study: Lolium perenne (cv. Kentaur), Festulolium pabulare (cv. Felina), Festulolium braunii (cv. Perseus), and mixtures of these species with Festuca rubra (cv. Gondolin) or Poa pratensis (Slezanka). The mycotoxins deoxynivalenol, zearalenone and T-2 toxin were mainly detected in the fresh-cut grass material, while fumonisin and aflatoxin contents were below the detection limits. July and October were the most risky periods for mycotoxins to occur. During the cold temperatures in November and December, the occurrence of mycotoxins in fresh-cut material declined. Although June was a period with low incidence of mycotoxins in green silage, contents of deoxynivalenol and zearalenone in silages from the first cutting exceeded by several times those determined in their biomass collected directly from the field. Moreover, we observed that use of preservatives or inoculants did not prevent mycotoxin production.

Investigation into the Effect of Molds in Grasses on Their Content of Low Molecular Mass Thiols

The aim of this study was to investigate the effect of molds on levels of low molecular mass thiols in grasses. For this purpose, the three grass species Lolium perenne, Festulolium pabulare and Festulolium braunii were cultivated and sampled during four months, from June to September. The same species were also grown under controlled conditions. High-performance liquid chromatography with electrochemical detection was used for quantification of cysteine, reduced (GSH) and oxidized (GSSG) glutathione, and phytochelatins (PC2, PC3, PC4 and PC5). Data were statistically processed and analyzed. Thiols were present in all examined grass species. The effect of fungicide treatments applied under field conditions on the content of the evaluated thiols was shown to be insignificant. Species influenced (p < 0.05) PC3 and GSSG content. F. pabulare, an intergeneric hybrid of drought- and fungi-resistant Festuca arundinacea, was comparable in PC3 content with L. perenne and F. braunii under field conditions. Under controlled conditions, however, F. pabulare had higher (p < 0.05) PC3 content than did L. perenne and F. braunii. Under field conditions, differences between the evaluated species were recorded only in GSSG content, but only sampling in June was significant. F. pabulare had higher (p < 0.05) GSSG content in June than did L. perenne and F. braunii.

16. Effect of Diet Supplemented with Antioxidants (Selenium, Copper, Vitamins E and C) on Antioxidant Status and Ejaculate Quality of Breeding Boars

Abstract The aim of the experiment was to determine the effect of selected antioxidants (selenium, copper, vitamins E and C) on the antioxidant status of breeding boar ejaculate and ejaculate quality. In the first control group of boars (n = 10), the amount of antioxidants was not increased in feed. The second experimental group (n = 10) received the addition of selenium (0.5 mg/kg of diet), copper (10 mg/kg of diet), vitamin C (350 mg/kg of diet) and vitamin E (70 mg/kg of diet) in feed. The experiment lasted for 90 days. The addition of antioxidants increased GPx (by 28%), selenium content (by 49%; P<0.05), SOD (by 9%; P<0.05) and level of copper (by 63%; P<0.05) in the experimental group of boars. In the control group, the decrease of sperm motility (by 22%; P<0.05) was found at the end of the experiment. Other measured parameters such as ABTS antioxidant capacity, levels of MDA, metallothionein, zinc, ejaculate volume, concentration, total count of sperm and percentage of abnormal sperm cells were not significantly affected. The above mentioned results show that the addition of antioxidants does not increase the ejaculate quality but their lack can damage the quality indicators of boar ejaculate.

Study of deoxynivalenol effect on metallothionein and glutathione levels, antioxidant capacity, and glutathione-S-transferase and liver enzymes activity in rats

Deoxynivalenol (DON, vomitoxin) is one of several human mycotoxins acquired through residues in foods of plant origin (cereals) and through foods of animal origin (kidneys, liver, milk, eggs). The aim of this study was to investigate the impact of deoxynivalenol-contaminated mouldy grain on the health status of rats and their ability to resist oxidative stress. The rats were fed a diet supplemented with DON along with organic and inorganic Zn(II), and vitamins for 28 days. The study focuses particularly on protective mechanisms and levels of reduced glutathione and metallothioneins (MT) against the adverse effects of xenobiotics. The highest concentrations of MT were detected in the tissues of kidneys ((6.70 ± 0.05) μg g−1) and liver ((6.00 ± 0.05) μg g−1), both of which are involved in detoxifying cationic xenobiotics. Lower concentrations were also detected in heart, brain, testes, and muscle tissues (approximately 3.0 μg g−1). Antioxidant capacity, glutathione-S-transferase, and liver enzymes activity were also studied. In conclusion, MT may play an important role in the detoxification of mycotoxins. Even though its role is not fully understood, MT are crucial for the redistribution of ions important for transcription factors and interaction with reactive oxygen species that form mycotoxins.

Antioxidant status of rats’ blood and liver affected by sodium selenite and selenium nanoparticles

Background Selenium is an essential element; however, at higher doses, it can be toxic. Therefore, alternative nanotechnological solutions are required to overcome toxicological issues, rather than conventional alternatives. Nanoparticles show new and promising properties that may be able to suppress toxicity while maintaining the positive effects of selenium on an organism. The aim of the experiment was to determine the influence of sodium selenite and selenium nanoparticles (SeNPs) on the antioxidant status of rats. Methods The males of the outbreed rat strain Wistar albino were selected as a model organism. Animals were fed different forms of selenium. The control group was given a mixture without selenium addition, whereas other groups were fed a mixture containing sodium selenite, Se-49, and Se-100 SeNPs respectively. The duration of the trial was 30 days. Results Analysis of blood and liver was performed where the concentration of reduced (GSH) and oxidised (GSSG) glutathione, and total selenium content were measured. In the liver, a significant reduction in GSSG was found for all experiment groups. Blood samples showed a significant reduction in GSH and an increase in GSSG. Discussion These results show that SeNPs may be an alternative to dietary selenium for animal organisms.

Determination of Histamine in Silages Using Nanomaghemite Core (γ-Fe2O3)-Titanium Dioxide Shell Nanoparticles Off-Line Coupled with Ion Exchange Chromatography

The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him) separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (γ-Fe2O3) functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles’ (PMP) surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.

Nanoparticles as a Solution for Eliminating the Risk of Mycotoxins

Mycotoxins are toxic secondary metabolites produced by certain filamentous fungi. The occurrence of mycotoxins in food and feed causes negative health impacts on both humans and animals. Clay binders, yeast cell walls, or antioxidant additives are the most widely used products for mycotoxin elimination to reduce their impact. Although conventional methods are constantly improving, current research trends are looking for innovative solutions. Nanotechnology approaches seem to be a promising, effective, and low-cost way to minimize the health effects of mycotoxins. This review aims to shed light on the critical knowledge gap in mycotoxin elimination by nanotechnology. There are three main strategies: mold inhibition, mycotoxin adsorption, and reducing the toxic effect via nanoparticles. One of the most promising methods is the use of carbon-based nanomaterials. Graphene has been shown to have a huge surface and high binding capacity for mycotoxins. Attention has also been drawn to polymeric nanoparticles; they could substitute adsorbents or enclose any substance, which would improve the health status of the organism. In light of these findings, this review gives new insights into possible future research that might overcome challenges associated with nanotechnology utilization for mycotoxin elimination from agricultural products.

Biogenic amines and hygienic quality of lucerne silage

Abstract This experiment examined the influence of two different silage additives of biological (Lactococcus lactis, Lactobacillus plantarum, Enterococcus faecium, enzyme xylanase) and chemical (43% formic acid, 30% ammonium formate, 10% propionic acid, 2% benzoic acid) types on biogenic amines concentration, nutrient content, fermentation process, and microbiologic indicators in lucerne (Medicago sativa) silage after 90 days of fermentation. The biological additive significantly (P < 0.05) increased putrescine (+51%), lactic acid (+11%) and protein content (+11%) in comparison with control silage. It significantly decreased cadaverine (−29%), histamine (−57%), spermidine (−15%), spermine (−55%), acetic acid (−40%), ethanol (−55%), ammonium (−25%) and ash (−9%). After the chemical-additive treatment, greater amounts of histamine and tyramine were recorded. Significant decrease was observed in the concentrations of putrescine (−18%), cadaverine (−55%), spermidine (−47%), spermine (−45%), lactic acid (−16%), acetic acid (−46%), ammonium (−59%), ash (−13%) and fat (−24%). Populations of bacteria associated with lactic acid fermentation, moulds, yeasts, enterobacteria and total microorganisms count were also influenced. Both biological and chemical additives can be highly recommended for producing high-quality silages meeting hygienic requirements. In lucerne silage, the chemical preservative showed a stronger effect in achieving the health safety of silage compared to the biological inoculant.

Effect of Streptococcus uberis infections on cell population of bovine mammary gland

Streptococcal bacteria are one of the most important pathogens causing different type of bovine mastitis. In this respect, it is very important to study effect of streptococcal infections on cell populations of bovine mammary gland to improve knowledge how to prevent and treat streptococcal infections of bovine mammary gland. Streptococcal bacteria can affect different cell processes, for example, programmed cell death (apoptosis) and expression of some cell receptors on leukocytes such as neutrophils, lymphocytes and macrophages of mammary gland. This review summarizes information about effect of streptococcal infections on leukocytes of bovine mammary gland.