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In 2016, the characteristics and approaches to art mediation as an educative approach to facilitation of understanding and experiencing art in Czech extracurricular field trips and school outreach programmes were defined and investigated by faculty members of Department of Primary Education within an independent research project. This paper presents a theoretical background to the investigation results. The research study used a qualitative research method of semi-controlled interviews with professionals from different extracurricular establishments. The goal was to achieve a holistic view of the current concept of visual art on the basis of extracurricular school programmes and their pedagogical potential and to describe and define the methodological specifics of this phenomenon using a research design based on datas gained from six extensive interviews. The open-coding analysis method used here reveals a generalised view of the topic. Thus it will provide clear reasons and way of implementation of art mediation from extracurricular environment to schools.

The objective of this study was to evaluate the concentrations of the total (T-GSH), oxidised (GSSG) and reduced (GSH) glutathione in the blood of dairy cows, assess the relationships of the phase and number of lactation, milk production, body condition score (BCS) and selected biochemical parameters on its concentrations. We analysed 79 samples of whole blood from dairy Holstein cows. The concentration of glutathione was assessed by the spectrophotometric enzymatic method. The whole dataset shows the mean concentration of T-GSH, GSSG and GSH of 803 ± 22 µmol/l, 23 ± 2.5 µmol/l and 757 ± 27 µmol/l, respectively. The GSH/GSSG ratio was 95 ± 17. The phase of the lactation had a significant impact on the levels of T-GSH and GSH, but the number of lactation and BCS had no effect. Dry cows had higher levels of T-GSH (938 ± 44 µmol/l) than the fresh (713 ± 46 µmol/l) and peak lactation (785 ± 45 µmol/l) cows. The fresh cows had significantly lower concentrations of GSH (618 ± 44 µmol/l) than the peak lactation (719 ± 46 µmol/l) and dry cows (827 ± 43 µmol/l). On the basis of a regression analysis, blood glutathione was affected mainly by the liver function and energy metabolism. Glutathione as the marker of oxidation stress seems to be a promising tool in monitoring the health and welfare of the herd, yet intensive research in this field remains necessary.

In 2016, the characteristics and approaches to art mediation as an educative approach to facilitation of understanding and experiencing art in Czech extracurricular field trips and school outreach programmes were defined and investigated by faculty members of Department of Primary Education within an independent research project. This paper presents a theoretical background to the investigation results. The research study used a qualitative research method of semi-controlled interviews with professionals from different extracurricular establishments. The goal was to achieve a holistic view of the current concept of visual art on the basis of extracurricular school programmes and their pedagogical potential and to describe and define the methodological specifics of this phenomenon using a research design based on datas gained from six extensive interviews The open-coding analysis method used here reveals a generalised view of the topic. Thus it will provide clear reasons and way of implementation of art mediation from extracullicular environment to schools.

The development of bankruptcies in the Czech Republic is closely related to the impact of the global financial economic crisis, which, among other things, has also affected the competitiveness of Czech companies to a great extent. The future state of overall company financial health can be determined through prediction models. This paper discusses the history of financial analysis and the most widely used models, with the main purpose of the paper to compare the accuracy of various prediction models and to decide which model has the highest prediction success rate. The sample consisted of the total of 90 Czech companies, out of which 1/2 were companies in bankruptcy and 1/2 were non-bankrupt companies. Ratio indicators of given models were calculated from balance sheets as well as profit and loss statements for a five-year period. The reliability of the accurate classification of accounting units is verified by a confusion matrix. The highest total success rate of classification was achieved by Zmijevski model, which had the highest predictive value. Another partial objective of the paper is to determine whether the accuracy rate of the bankruptcy models changes with branches within which the companies operate. The hypothesis about differences between the branches is confirmed. The most statistically significant differences were shown between Wholesale and Retail and the Processing Industry, with the results of models varying among different branches. The results show that taking into account the branches the company is operating in is advisable for selecting prediction models.

The objectives of this study were to determine the immunoglobulin G concentration of colostrum in Czech dairy cows, to compare refractometer results with results achieved using the radial immunodiffusion method and to evaluate the reliability of three types of refractometers and recommend the best solution for the evaluation of colostrum quality. Colostrum samples (n = 1522) were collected from 38 herds between 2015 and 2017. The immunological quality of colostrum was estimated using Brix refractometers (optical, simple digital, digital Misco) and compared with the immunoglobulin G concentration assessed using radial immunodiffusion. We found high variability in the quality of colostrum. The minimum, maximum and median of individual measurements were the following: radial immunodiffusion immunoglobulin G - 5.2, 199.1, 76.9 g/l; optical refractometer - 9.5, 32.0, 23.1% Brix; simple digital refractometer - 5.4, 35.0, 19.1% Brix; digital refractometer Misco - 9.8, 37.4, 23.2% Brix. On the basis of immunoglobulin G concentration assessed using radial immunodiffusion, 20.9% of colostrum samples were of low quality (immunoglobulin G < 50 g/l). The Spearman correlation coefficients between radial immunodiffusion and the Brix refractometer readings were 0.62-0.67 (P < 0.001) according to the type of refractometer. The cut-off evaluation of the readings from optical and Misco digital refractometers both showed 20% Brix, with sensitivities of 89.4% and 88.2%, specificities of 73.2% and 74.5% and accuracies of 86.0% and 85.4%, respectively. The cut-off level for the simple digital refractometer showed 17% Brix with a sensitivity of 77.5%, specificity of 80.4% and an insufficient accuracy of 78.1%. For optical and Misco refractometers we recommend the use of two cut-off levels for the evaluation of colostrum: 23% Brix for the selection of good quality colostrum suitable for freezing and 19% Brix to discard poor quality colostrum. The different cut-off levels obtained by measuring with different types of refractometers indicate the need to check the quality of the instruments prior to their use in practice and, where appropriate, to determine their cut-off levels by comparison with results obtained using the reference method.

Research background: Although the world is still in a coronavirus crisis, it also sees hope in vaccines being developed, government measures taken to revive the economy and borders reopening. At the same time, the globalized world has learned a lot. Knowledge management and knowledge sharing in a globalized world now have even higher mission than before, since work regimes have completely changed and the necessary requirements for the protection of employees´ health and safety are being adopted. Purpose of the article: Knowledge management is a multidisciplinary activity; its individual disciplines will be described, characterized and researched. Research surveys will map the activities of knowledge management in new work regimes with the protection of employee health and safety in order to optimize knowledge management of businesses in a globalised world with existing threats. Methods: After the questionnaire survey is completed, the respondents’ answers will be encoded in Microsoft Excel. The encoded data will be exported to the SPSS statistical software. The objective of the statistical evaluation is to extract relationships and linkages that could contribute to optimising the knowledge management of enterprises in a globalised world. To detect basic relationships and linkages, Pearson’s chi-square test of independence will be used at the level of descriptive statistics, using contingency tables. Findings & Value added: Based on the conducted research, it diagnoses existing knowledge management barriers and knowledge sharing in globalized enterprises.

Abstract The additive, ‘Zinc‐l‐selenomethionine’ (Zn‐l‐SeMet) is intended to be used as a source of selenium for all animal species. The applicant intends to market the active compound blended with inert carriers (Availa®Se). Zn‐l‐SeMet is a safe source of selenium for chickens for fattening; the conclusion is extended to all animal species. Selenium from Zn‐l‐SeMet does not elicit any adverse effects not expected for a selenium compound. The use of Zn‐l‐SeMet in animal nutrition is expected to result in a similar increase in selenium deposition in animal tissues/products as that resulting from other sources of SeMet. The use of the additive up to the maximum selenium supplementation level established for other sources of organic selenium (0.2 mg/kg complete feed) and complying with the maximum authorised total selenium content is safe for consumers. The additive is hazardous upon inhalation; owing to the high dusting potential, persons handling Availa®Se are at risk by inhalation. Availa®Se is not an irritant to the skin. In the absence of data, no conclusion on the eye irritation and skin sensitisation can be drawn. The use of Zn‐l‐SeMet in feed does not pose an additional risk to the environment, compared with other sources of selenium for which it will substitute, as long as the maximum authorised content in complete feed is not exceeded. Zn‐l‐SeMet is an effective source of selenium in chickens for fattening and laying hens; this conclusion is extended to all animal species. The maximum contribution of zinc in total feed deriving from the use of the additive (

The aim of this study was to establish reference intervals for the haematological profile of alpacas on the basis of a large population of clinically healthy animals, and to determine the influence of sex, age and season on these indicators. Blood samples were collected from 243 alpacas (53 males and 156 females over six months of age and 34 crias - 12 males and 22 females - under six months of age). The selected farms were located in Central Europe (Czech Republic and Germany). We determined 13 haematological indicators. Comparison of the results was performed with respect to the sex of animals and for the older group also with regard to the season and to the feeding period. We found no highly significant (P > 0.001) differences between males and females. We did find highly significant differences (P < 0.001) between the group of crias under six months of age and the older alpacas (mean corpuscular volume - MCV, mean corpuscular haemoglobin concentration - MCHC, red cell distribution width - RDW, white blood cell count - WBC, neutrophil count). Based on our findings we suggest that for some indicators different reference intervals (esp. WBC and differential cell counts) be used for the two above mentioned age groups. We found some highly significant differences (P < 0.001) in haematological indicators in the older group of alpacas between the summer and winter feeding period (haemoglobin concentration, MCHC). Clinical laboratory diagnosis may be improved by the use of age-based and season-based haematological reference values.

This article examines the status of women in labor market conditions within the European Union member countries. Since the women's status in the labor market and their participation in the labor process belong to one of the most discussed topics, we decided to analyze selected indicators and to compare them using cluster analysis method. The main objective of this article is to present an analysis of the situation and position of women in the labor markets of 28 member states of the EU using selected Quality of Life Indicators. The method of cluster analysis is applied in order to group countries with similar gender and labor market characteristics together. Key Words: Cluster Analysis, Labor Market, European Union, Women's status, Introduction Women represent more than one half of the world's population but according to many researchers, 'their contribution to the economic activity measured by the growth and well-being is below [...]

Abstract Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of selenium‐enriched yeast (Saccharomyces cerevisiae CNCM I‐3399) for all animal species, based on a dossier submitted for the modification of the terms of authorisation of the additive. The additive is currently authorised as selenomethionine produced by S. cerevisiae CNCM I‐3399 as a nutritional additive (compound of trace elements) with a minimum selenium content of 2,000 mg/kg. The applicant proposed the inclusion of an additional formulation with a minimum content of selenium in the additive of 3,000 mg/kg. Considering (i) that there are no relevant changes in the manufacturing of the product compared to the former application and (ii) that the conditions of use already authorised remain the same, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) stated that the modification requested would not affect the conclusions of the FEEDAP Panel on safety for the consumer, safety for the environment and efficacy of the product made in a previous assessment of a similar product with a lower selenium concentration. Since the capacity of the additive to homogeneously distribute in feed was proven, the tolerance studies already provided for the currently authorised product could be used to conclude on the safety of the additive for the target animals. Selenium is hazardous upon inhalation; owing to the dusting potential and the selenium content of dust, persons handling the additive are at risk. The additive should be considered as a respiratory sensitiser. The additive is not an irritant for eyes and skin. No conclusions can be reached on the dermal sensitising properties of the additive.

Abstract The additive ‘Zinc chelate of methionine sulfate’ is zinc chelated with methionine in a molar ratio 1:1, with a minimum zinc content of 19.1%. Owing to the limitations of the tolerance study, it could not be used for the assessment of safety for target animals; therefore, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) cannot conclude on the safety of zinc chelate of methionine sulfate for the target species. No concerns for consumer safety are expected from the use of the zinc chelate of methionine sulfate in animal nutrition when used up to the maximum EU authorised zinc levels in feed. Zinc chelate of methionine sulfate should be considered as a skin and eye irritant, and as a skin sensitiser; it is considered to pose a risk by inhalation to the users. The additive under assessment, zinc chelate of methionine sulfate, is intended to be a substitute for other authorised zinc additives and will not further increase the environmental burden of zinc; therefore, the FEEDAP Panel considers that the use of the additive in animal nutrition would not pose an additional risk for the environment. Based on literature studies and a specific study conducted with the additive under assessment, zinc chelate of methionine sulfate is an available source of zinc for all animal species.

The aim of this study was to establish reference interval for biochemical parameters in blood of alpacas on the basis of large population of clinically healthy animals, and to determine the influence of sex, age and season on nitrogen and lipid metabolites, enzymes, electrolytes, vitamins and minerals in blood of alpacas. Blood samples were collected from 311 alpacas (61 males and 201 females >6 months of age and 49 crias (21 males and 28 females) ⩽6 months of age). Selected farms were located in Central Europe (Czech Republic and Germany). We determined 24 biochemical parameters from blood serum. We performed the comparison of results by the sex of animals and for the older group also the comparison of the results with regard to the season, respectively, to the feeding period. We found no highly significant difference (P

The assessment of weak acid membrane permeability (Pm) frequently involves large unilamellar vesicles. It relies on measurements of the intravesicular pH drop, ΔpHin, in response to a sudden augmentation of external acid concentration. However, ΔpHin may be primarily governed by non-instantaneous protonation and deprotonation reactions of (i) the acid itself, (ii) the buffer molecules, and (iii) the fluorescent pH reporter dye. Moreover, buffer concentration and acid gradient also serve as determinants of ΔpHin, as we show here. The uniexponential time constant (τ) of ΔpHin(t) is an invalid measure of Pm as Arrhenius plots of Pm and τ reveal different activation energies for acid influx. We calculate Pm by fitting a mathematical model to experimental stopped-flow traces. The model takes into account not only the time course of total internal buffer capacity but also (i) water self-dissociation, (ii) volume changes due to acid induced osmotic water flow, and (iii) the spontaneous membrane proton leak. It allows extracting a Pm of 30.8 ± 3.5 μm/s for formic acid for 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) vesicles.

The aim of this study was to evaluate a new device for the ultrasound-guided transvaginal aspiration of follicular fluid for acid-base balance analysis (ABB set) in comparison with the original modified commercial OPU set. In the ABB set, an aspiration syringe was placed in the front part of the new tool's handle, next to the transducer, so as to enable direct collection of the sample into the syringe. To obtain a sufficient amount of testable fluid, reservoirs of urine (rubber balloons) were used for later aspiration under laboratory conditions in Experiment 1. Fifteen triads of samples (each triad with two punctures) were collected. While the first sample of each triad was taken using the ABB set (ABB sample), two samples were taken by one puncture using the original modified commercial OPU set: aerobic phase of sampling (AE sample) with air present in the tubing at the start of sampling and the subsequent anaerobic phase of sampling (AN sample). Values determined in the second sample from the triad (AE) varied from the values in both ABB and AN samples (pH 7.685 vs. 7.704 vs. 7.692, pCO2 11.13 vs. 10.3 vs. 10.85, pO2 6.87 vs. 8.67 vs. 7.02). In Experiment 2, ultrasound-guided transvaginal aspirations were carried out in 13 cows bearing ovarian cysts with diameters of at least 3 cm, using plastic aspiration syringes (Experiment 2P) and in 12 cows using glass aspiration syringes (Experiment 2G). The sequence of samples was the same as in Experiment 1. We found a significantly higher pH in AE in comparison to AN (7.357 vs. 7.348), lower pCO2 (6.85) and higher O2 (14.12) in samples of AE in comparison to samples of ABB and AN (pCO2 7.36, 7.30; O2 9.95, 10.63 respectively) in cystic fluid in Experiment 2P. We found a significantly higher pH (7.4), lower pCO2 (5.98) and a higher pO2 (12.35) in AE samples in comparison to ABB and AN samples of cystic fluid (pH 7.386, 7.385; pCO2 6.39, 6.35 and O2 10.56, 10.65, respectively) from Experiment 2G. We conclude that the acid-base balance assay was affected by air, present in the tubing during aerobic sampling in comparison to anaerobic and ABB set sampling. These pre-analytical changes can be prevented by the use of the ABB set because the results obtained with the ABB set were not different from that of the AN samples. We also confirmed pre-analytical changes in acid-base balance parameters in the cystic fluid after it had been stored in plastic aspiration syringes. Our new ABB set equipped with a glass aspiration syringe is suitable for sampling follicular fluid for both acid-base balance and gas analysis.

The aim of this trial was to compare the effect of supplementation of goats with different forms of selenium on the metabolism of their kids at the time of weaning. The experiment was performed with 45 kids of mothers supplemented with various forms of selenium. Group C was control while the other four groups were supplemented with selenium for six weeks before (0.3 mg/goat/day) and after parturition (0.9 mg/goat/day). Group Se-I received sodium selenite while the other groups received organic forms: Se-lactate-protein complex (Se-L), Se-proteinate (Se-P) and Se-yeast (Se-Y). The kids were weaned at three months of age and samples of blood and urine were taken. Parameters monitored in the blood included Se, glutathione peroxidase (GPx), Zn, Cu, thyroxine, triiodothyronine, protein, immunoglobulins, muscle enzymes, total antioxidant status, vitamin A and E. Se levels were determined In the urine. Selenium supplementation of goats from six weeks before delivery significantly influenced selenium concentrations in the blood of kids. Significant differences (P < 0.0002) were found between the control and all experimental groups and further between Se-Y and the other experimental groups (Se-Y: 243.0 ± 20.3 μg/l; Se-I: 156.3 ± 34.3 μg/l; Se-P: 152.6 ± 41.5 μg/l; Se-L: 146.7 ± 20 0 μg/l; C: 67.6 ± 13.1 μg/l). The highest concentration was found in the group supplemented with Se-yeast with a high content of selenomethionine. The other two organic forms of selenium (proteinate and lactate-protein complex) increased the concentration of Se in blood and the activity of GPx to the same extent as the inorganic form of selenium. Se supplementation did not have a negative effect on the concentration of copper and zinc in the blood serum of kids, but we found decreased concentrations of thyroxine in the experimental groups (Se-Y: 79.8 ± 12.8 nmol/l; Se-I: 66.5 ± 13.2 nmol/l; Se-P: 76.2 ± 25.7 nmol/l; Se-L: 84.5 ± 14.8 nmol/l; C: 92.7 ± 13.4 nmol/l). Significant differences were found between the group C and groups Se-I and Se-P (P < 0.05). The supplementation of mothers with Se both in organic and inorganic forms was sufficient to prevent Se deficiency in kids at the time of weaning.

The aim of this study was to determine the relationship between selenium concentration and activity of glutathione peroxidase (GSH-Px) in the whole blood of sheep and reference ranges for the activity of GSH-Px for evaluation of the selenium status of sheep in the Czech Republic. Selenium concentration and activity of glutathione peroxidase were determined in whole blood samples collected from 92 sheep in six herds. The GSH-Px activity in the samples was measured using the photometric method. Selenium in the sample was measured using the hydride technique atomic absorption spectrometry. Data on both parameters were processed using correlation and regression analysis in order to obtain reference values of GSH-Px for the indirect evaluation of the selenium status of sheep. The two variables showed a close and significant correlation (r = 0.95; P < 0.01). The regression line, defined by the equation y = 7.5857x - 121.87 (linear) or y = -0.0167x2 + 11.993x - 355.57 (polynomial), allowed us to determine the GSH-Px activity of 637, resp. 677 μkat/l as equivalent to selenium concentration in whole blood of sheep 100 μg/l. Mean selenium concentration and mean GSH-Px activity found in whole blood samples were 123.42 ± 57.84 μg/l and 814.34 ± 463.64 μkat/l, respectively. In this study, a close dependence of GSH-Px activity on the selenium concentration in the blood of sheep was found. Activity values of GSH-Px were determined for use in the diagnosis of sufficient selenium status in sheep in the Czech Republic (GSH-Px activity greater than 600 μkat/l of whole blood).

The goal of the experiment was to compare the effect of supplementation of inorganic and the new organically bound (lactate-protein selenium complex) form of selenium (Se) in feed for goats. The 31 goats were split into three groups: control (C) without Se supplementation, AN group administered sodium selenite, ORG group administered lactate-protein selenium complex (Selene Chelate, Agrobac, Czech Republic) produced by cultivation of Lactobacillus acidophilus on a substrate containing natrium selenite. The total Se intake in goats was 0.15 mg in group C, and 0.43 mg in the groups AN and ORG. The effect of Se supplementation was assessed based on the determination of Se concentration and the activity of glutathione peroxidase (GSH-Px) in whole blood. Samples were taken before the beginning of Se supplementation, 14 and 30 days after the start of supplementation, and then two and three months after the beginning of supplementation. Average Se concentrations in the blood of goats in individual groups (C, AN, ORG) before the start of supplementation were 109.6 ± 34.3, 117.5 ± 34.7, and 105.4 ± 43.6 μg/l respectively, and the activity of GSH-Px in whole blood was 745.3 ± 289.2, 810.7 ± 280.4, and 791.0 ± 398.1 μkat/l respectively. While in group C goats neither the Se concentration nor the GSH-Px activity changed substantially during the experiment, in the goats in the experimental groups there was a statistically significant increase (P < 0.01) in both Se concentrations and the GSH-Px activities. At the end of the experiment Se concentrations in the blood of AN and ORG groups amounted to 168.5 ± 12.2 and 168.8 ± 26.8 μg/l. The GSH-Px activities in goats supplemented with Se also increased significantly over the course of the experiment (at the end of the experiment it was 1178.0 ± 127.3 in the AN group and 1030.1 ± 152.3 μkat/l in the ORG group), and the difference between the groups was significant (P = 0.038). Regarding the dynamics of GSH-Px activity changes during the monitored period, a markedly quicker increase in GSH-Px activity was recorded in the AN group - one month after the beginning of Se supplementation, compared to three months after the beginning of Se supplementation in the ORG group. The results thus show that the effects of supplementation with selenite and the lactate-protein selenium complex are similar with regard to Se status, but that the increase in GSH-Px activity occurred much faster with selenite, which therefore appears to be a more biologically available form of selenium for creation of biologically active selenoproteins.

This paper evaluates the impact of long-term supplementation of different forms of zinc (Zn) and selenium (Se) on the content of these substances in the blood and hair of goats. Two analogous supplementation experiments were performed. 37 goats divided into four groups were used in the first trial with the Zn supplementation. Group A (n = 10) was a control group (with no Zn administered). A further three groups (B, C, D) were supplemented with Zn in various forms. Group B (n = 9) with zinc oxide, Group C (n = 9) with zinc lactate and Group D (n = 9) with zinc chelate. The second trial with Se supplementation was carried out on 20 goats divided into four groups. Group E (n = 5) was a control group. The other three groups were administered Se. Group F (n = 5) was supplied with a selenium lactate-protein complex, Group G (n = 5) with sodium selenite and Group H (n = 5) with selenium yeast. Three months later blood and hair samples were taken from all animals and Zn and Se concentrations were determined in whole blood, plasma, and hair. Glutathione peroxidase (GSH-Px) activity was determined in the Se supplementation trial group. At the end of the trial the Zn concentrations in plasma and whole blood were without major differences between the groups. The plasma concentration of Zn did not increase from the initial value at the start of the trial. In hair the average concentration of Zn was 95.2-100.0 mg/kgin all groups. No conclusive relation was confirmed between the values of Zn in hair and its concentration in blood. The Se concentration in whole blood (µg/l) at the end of trial in supplemented groups (F - 188.8 ± 24.6; G - 197.2 ± 10.9; H - 190.1 ± 26.3) was significantly higher (P < 0.01) than in the control group (E - 103.1 ± 23.5). Similarly, the activity of GSH-Px (µkat/l) was significantly higher in all supplemented groups (F - 872.3 ± 94.8; G - 659.5 ± 176.4; H - 839.8 ± 150.8) than in the control group (E - 379.1 ± 63.5). Se content in hair (µg/kg) was higher also in all trial groups (F - 242.3 ± 41.5; G - 200.5 ± 46.9; H - 270.0 ± 106.8) than in the control group (E - 174.7 ± 38.0). However, it was significantly (P < 0.05) higher only in Group F. A conclusive correlation was identified between the Se concentration in whole blood and its content in hair (r = 0.54; P < 0.05; n = 20). Based on the results it can be concluded that none of the supplemented forms of Zn increased its concentration in blood, plasma and hair. On the other hand, the administration of Se led to an increase in the Se concentration in blood, increased the activity of GSH-Px in whole blood and the Se content in hair. Based on the proven correlation and regression relation between the Se concentration in blood and its content in hair, hair can be considered as a suitable material for the diagnosis of long-term Se status in goats. Goats with sufficient Se status are those that have more than 160 µg/kg of Se in hair dry weight.

The aim of this study was to evaluate the effect of a long-term peroral selenium supplementation in the form of sodium selenite and selenium lactate-protein complex by comparing selenium concentrations and glutathione peroxidase activity in blood of goats and their kids as well as comparing selenium concentrations in goat colostrums. For the study, a total of 27 clinically healthy pregnant white shorthair goats were used. They were divided to three groups, i.e., the control group (C) without any selenium supplementation, sodium selenite group (E1) and selenium lactate-protein complex group (E2). For four months, experimental goats received 0.43 mg of selenium per animal per day in diet; goats from the control group were given 0.15 mg of selenium per animal per day. At the beginning of the experiment, goats of all groups showed an average selenium concentration of 96 μg/l in whole blood. On the parturition day, samples of first colostrum from goats and heparinized blood from goats and kids were taken. In the control group (C), average blood selenium concentrations of 111.4 ± 33.5 μg/l were observed on the parturition day. In both experimental groups, selenium concentrations were significantly higher (P < 0.05). Average selenium concentration in the sodium selenite group (E1) was 177.2 ± 34.8 μg/l and in the group supplemented with selenium lactate-protein complex (E2) 159.0 ± 28.5 μg/l. Average glutathione peroxidase (GSH-Px) activity in blood of control goats (C) was 581.9 ± 99.2 μkat/l, in group E1 1 154.6 ± 156.2 μkat/l and in group E2 1 011.6 ± 153.6 μkat/l. GSH-Px activity in experimental groups was significantly higher (P < 0.05) as compared with the control group. Average selenium concentrations in colostrum was in the control group 40.1 ± 12.8 μg/l, in E1 99.0 ± 29.9 μg/l and in group E2 79.0 ± 17.7 μg/l. Colostral selenium concentrations in experimental groups were significantly higher (P < 0.05) as compared with the control group. No significant difference in the monitored parameters was found between experimental groups. In kids of control mothers (kC), average selenium concentrations in blood on the parturition day were 62.4 ± 22.9 μg/l; kids of mothers supplemented with sodium selenite (kE1) showed average selenium levels of 100.0 ± 31.2 μg/l, and the average selenium concentration in kids of mothers receiving lactate-protein complex was 83.4 ± 20.1 μg/l (kE2). Average GSH-Px activity in control kids (kC) was 402.1 ± 153.9 μkat/l. Kids from kE1 showed average activity of GSH-Px 806.1 ± 254.9 μkat/l and kids from group kE2 529.9 ± 119.8 μkat/l. Statistically significant difference (P < 0.05) was found only between kC and kE1 which showed significantly higher selenium concentration and GSH-Px activity. The results of this study confirm that both forms of selenium administered in experimental groups (i.e., sodium selenite and selenium lactate-protein complex) had similar biological effect in goats. However, results obtained in kids indicate a better effect of supplementation with sodium selenite.

The aim of our study was to compare the concentration of selenium (Se) and the activity of glutathione peroxidase (GSH-Px) in the whole blood of goats and their newborn kids. The experiment involved 25 gravid, clinically healthy goats of the white shorthaired breed. On the day of delivery, we took whole blood from the mother and her newborn kid before the kid drank the first colostrum. In mothers, the measured average concentration of Se in whole blood was 149.60 ± 45.01 μg/l, the average concentration of Se in kids was 87.91 ± 29.66 μg/l. Average activity of GSH-Px in the blood of mothers was 938.46 ± 341.09 μkat/l, and in the blood of kids 658.20 ± 339.13 μkat/l. Regression and correlation analysis produced regression line formulas and correlation coefficients that revealed a close, statistically significant relation (P < 0.01) between the concentration of Se in the blood of mothers and their kids and the activity of GSH-Px in mothers and their kids. The relation between the concentration of Se in the blood (μg/l) of mothers and kids was γ= 0.484x + 15.55; r = 0.73, the relation between the activity of GSH-Px in blood (μkat/l) of mothers and their kids was γ = 0.809x - 101.27; r = 0.80. The concentration of Se and activity of GSH-Px was lower in newborn kids than in their mothers, reaching approximately 60-70% of the mother's levels. The relation between the concentration of Se and activity of GSH-Px in the blood of goats was γ = 4.23x + 276.31; r = 0.64 (P < 0.01) and the relation between the concentration of Se and the activity of GSH-Px in the blood of kids was γ = 6.556x + 64.70; r = 0.83 (P < 0.01). It follows that a Se concentration of 100 μg/l corresponds to a GSH-Px activity of 699.51 μkat/l in the blood of mothers and 720.34 μkat/l in the blood of kids. The results show the need to provide for a sufficient Se saturation of goats with a view to preventing Se deficiency in kids and that the Se concentration in the blood of newborn kids is physiologically about 40% lower in comparison with the Se concentration in the blood of their mothers. This should be taken into account when interpreting the results and assessing the reference values of Se concentration in the blood of kids.

Chromium (Cr) has been studied since the end of the 19th century, when carcinogenic effects of hexavalent Cr were discovered. Essentiality of trivalent Cr was demonstrated in 1959; Cr3+ has been studied in humans and laboratory animals since the 1970s and it is only since the 1990s that Cr has been studied as an essential element in livestock animals with the same intensity. Trivalent chromium is essential to normal carbohydrate, lipid and protein metabolism. Chromium is biologically active as part of an oligopeptide - chromodulin - potentiating the effect of insulin by facilitating insulin binding to receptors at the cell surface. With chromium acting as a cofactor of insulin, Cr activity in the organism is parallel to insulin functions. Cr absorption is low, ranging between 0.4 and 2.0% for inorganic compounds while the availability of organic Cr is more than 10 times higher. Absorbed Cr circulates in blood bound to the β-globulin plasma fraction and is transported to tissues bound to transferrin. Absorbed Cr is excreted primarily in urine, by glomerular filtration; a small amount is excreted through perspiration, bile and in milk. The demand for Cr has been growing as a result of factors commonly referred to as stressors, especially during different forms of nutritional, metabolic and physical strain. This review describes Cr metabolism, the different biological functions of Cr and symptoms of Cr deficiency.