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The aim of this thesis was to develop a literature search and experimentally determine the effect of organic forms of selenium levels (0.3 and 0.6 mg/kg FM) of selenium on the antioxidant status in postpartum sows. Experiment included 18 sows in the postpartum period, which were divided into three groups according to age. The model animals were divided into three groups. The first group (Se1) sows (n = 6) served as a control, wherein the addition of selenium has not been increased. The second group (Se2) sows (n = 6) were fed 0.3 mg Se/kg FM. Third group (Se3) sows (n = 6) were fed 0.6 mg Se/kg FM. Premix was dosed in the morning feeding. To supplement selenium were used selenium enriched yeast (Sel-Plex - Alltech's). The results show that the dose of selenium in an amount of 0.30 and 0.60 mg/kg FM, increase the activity of antioxidant enzymes, glutathione peroxidase and superoxide dismutase. Glutathione peroxidase (GPx) after supplementation with 0.3 mg/kg selenium increased from the second sampling, but the third sampling was statistically significant (P <0.05). Doses of 0.6 mg/kg selenium also visibly increased level of glutathione, but these results can not be statistically demonstrated. Superoxide dismutase (SOD) at both doses (0.3 and 0.6 mg/kg) appeared selenium statistically not detectable visible growth. We also found an increase of antioxidant activity measured by the methods ABTS, FRAP and FR, although the methods ABTS and FR showed slight fluctuations. The amount of reduced and oxidized glutathione were also significantly (P <0.05) higher in both experimental groups. The selenium content of selenium supplementation significantly affected when the results of both experimental groups were statistically significant (P <0.05) higher. Level malonyldialdehydu (MDA) after supplementation with 0.3 mg/kg selenium statistically proven (P <0.05) increased in the third collection at 0.6 mg/kg selenium, we observed statistically demonstrable (P <0.05) increase from the second collection. We can therefore conclude that selenium supplementation in organic form, can reduce oxidative stress in confinement of sows and overcome this stressful period for the organism.

This diploma thesis Increasing the supply of organism cattle selenium through its injection deals with the use of injection of selenium in beef cattle to aid in the supply of organism with selenium. The first part deals with selenium in general, its metabolism and function in the body. It deals with issues of selenium deficiency and subsequent therapy. The second part is focused on methodology and research results. The experiment was conducted on a herd of beef cattle breed Aberdeen-Angus at a private breeder in southern Bohemia. The herd of mothers were bled to determine the baseline selenium in their blood, then half of the herd was injected with a dose of Selevit and the second half of the herd served as a control. After birth blood was drawn from mothers as well as from their calves. The experimental group had a higher concentration of selenium in the blood, in the herd of mothers the attempt was inconclusive. The calves from mothers in the selenium group had significantly higher levels of selenium in there blood.

This thesis deals with the further development of the technique of generation of volatile compounds as derivatization methods by speciation analysis of selenium compounds. Specifically, this diploma thesis compares technique chemical and electrochemical generation of selected species of selenium (inorganic Se (IV) inorganic Se (VI), selenomethionine (Se- Met), selenocysteine (Se-Cys), methyl-selenocysteine (Met-Se-Cys) and seleno-urea (Se-U)). The achieved basic analytical characteristics are compared of each species in non-column arrangement with atomic fluorescence spectrometry. The effect of pre- reduction/decomposition unit are tested, using the pre-reduction agent KBr and hydrochloric acid at higher temperature and in the presence of UV radiation. Keywords Selenium, speciation analysis, chemical hydride generation, electrochemical hydride generation, atomic fluorescence spectrometry

Šnajdr Vladimir: Selenium in the diet of dairy cows in organic farming, Final thesis, Mendelu Brno, 50 pages. Selenium is one of a number of trace elements that are indispensable for the life of all species. Exceeding limits of the daily dose of selenium in the diet can cause toxicity of tthe organism. However, selenium deficiency can lead to diseases, particularly for species with high susceptibility to various kinds of diseases. The aim of the thesis was to investigate the influence of dietary selenium on qualitative and quantitative parameters of dairy cows in organic farming. The experiment itself was made on an organic dairy farm. The experiment involved 20 pieces of Holstein breed cows. They were divided into two balanced groups being at same stage of lactation. All the cows were fed a basic ration in the form of TMR with the addition of mineral premix Detamin GA Spezial designed for organic farms. The experimental and control group of cows took of 20.5 kg dry matter of feed/head/day. The basal diet contained 0.17 mg selenium /kg. Animals had ad libitum access to water. Selenium was added to the diet at the dose of 0.3 mg/kg (as selenomethionine) in the first group of cows (n=10). The second group of cows (n=10) served as a control without addition of selenium (control group of animals received only selenium from native sources). At the end of the experiment was after administration of selenium in the diet after 15 days in the group of cows examined detectable amount of selenium, which was constant throughout the duration of the experiment. The experimental group with selenium level ranged from 15 to 45 days in the interval from 0.13 to 0.15 mg/ml. In the control group, the amount of selenium throughout the entire duration of the experiment under the detection limit. The quantity of somatic cells was significantly reduced in the test group cows 128 thous./ml (P <0.05). Reducing the number of somatic cells was also observed even in the control group (about 49 tis./ml). The urea concentration significantly decreased in the experimental and control groups of 14.3 mg/100 ml (P <0.05) respectively about 13.7 mg/100 ml (P<0.05). The addition of selenium can improve animal health and to ensure the production of so-called functional foods Formula clause:Prohlašuji, že jsem práci: Selen ve výživě dojnic v ekologickém chovu vypracoval samostatně a veškeré použité prameny a informace uvádím v seznamu použité literatury. Souhlasím, aby moje práce byla zveřejněna v souladu s § 47b zákona č. 111/1998 Sb., o vysokých školách ve znění pozdějších předpisů a v souladu s platnou Směrnicí o zveřejňování vysokoškolských závěrečných prací. Jsem si vědom, že se na moji práci vztahuje zákon č. 121/2000 Sb., autorský zákon, a že Mendelova univerzita v Brně má právo na uzavření licenční smlouvy a užití této práce jako školního díla podle § 60 odst. 1 autorského zákona. Dále se zavazuji, že před sepsáním licenční smlouvy o využití díla jinou osobou (subjektem) si vyžádám písemné stanovisko univerzity, že předmětná licenční smlouva není v rozporu s oprávněnými zájmy univerzity, a zavazuji se uhradit případný příspěvek na úhradu nákladů spojených se vznikem díla, a to až do jejich skutečné výše.

The diploma thesis is focused on a small-plot year-long experiment, carried out in 2013. The experiment monitored reaction of sunflower's (Helianthus annuus L.) hybrid NK Brio to foliar fertilizing with selenium, applied in the form of sodium selenite (Na2SeO3) during growth stage R1, at rates 50, 100, 150 and 200 g Se.ha-1. Foliar application of selenium at rates 50 - 150 g.ha-1 caused stimulation of weight of a plant biomass and nutrient uptake (esp. N, Mg and Se). Rate of 200 g Se.ha-1 inhibited plants' growth. Sunflower achenes yields were not statistically significantly influenced by foliar application of Se (p0,05). The most significant effect of foliar application of Se was its content in sunflower achenes; the amount of Se increased significantly (p0,05) in a linear relationship (r = 0.9824) to the graded rates.

Previously, selenium was known as an element with negative properties. However, in the last century, the significant positive effects on human health were detected. Currently, the function, behavior and toxicity of selenium are still not well known. The key to understand it is to do speciation analysis. The aim of this diploma thesis is to develop method for determination inorganic (sodium selenite and selenate) and organic (selenourea, selenocystine, selenomethionine) selenium compounds. Parameters of apparatus for electrochemical hydride generation with atomic absorption spectrometry detector were optimized, final conditions were set and optimal conditions for separation process using HPLC were investigated. Calibration dependences for selenium compounds were measured and analytical figures of merit were investigated. In conclusion, a coupled method HPLC- EcHG- QFAAS for determination of individual selenium compounds was proposed, and it was tested on urea samples. Calibrations for these measurements were investigated and analytic characteristics were calculated. Based on these comparisons it can be said that proposed method allows the determination of selected selenium compounds in both aqueous and urea matrices. Subject words: Spectroscopy, analytical chemistry Key words: Atomic absorption...