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Research conducted during the 1980s demonstrated Se deficiency in humans. Increased inclusion of selenium in animal feeds started from the year 2000 onwards. The aim of this study was to estimate the effects of selenium inclusion in animal feeds on human selenium status and dietary habits of the Serbian population related to food of animal origin. Plasma selenium concentration in healthy adult volunteers, including residents of one of the regions with the lowest (Eastern Serbia, n = 60) and of one of the regions with the highest Se serum levels reported in the past (Belgrade, n = 82), was determined by hydride generation atomic absorption spectrometry. Multivariate analysis was employed to determine the correlation between Se plasma levels and dietary intake data derived from food frequency questionnaires and laboratory tests. The mean plasma Se level of the participants was 84.3 +/- 15.9 g/L (range: 47.3-132.1 g/L), while 46% of participants had plasma Se levels lower than 80 g/L. Frequency of meat, egg, and fish consumption was significantly correlated with plasma selenium level (r = 0.437, p = 0.000). Selenium addition to animal feed in the quantity of 0.14 mg/kg contributed to the improvement of human plasma selenium levels by approximately 30 mu g/L.

The typical Serbian diet is characterised by high intake of cereal products and also legumes are often used. The content of total fibre as well as certain fibre fractions was determined in cereals, cereal products, and cooked legumes. The content of total fibre in cooked cereals and cereal products ranged from 2.5 to 20.8 g/100 g, and in cooked legumes from 14.0 to 24.5 g/100 g (on dry matter basis). Distribution of analysed fibre fractions and their quantities differed significantly depending on food groups. Fructans and arabinoxylans were the most significant fibre fractions in rye flakes, and beta-glucan in oat flakes, cellulose and resistant starch were present in significant amounts in peas and kidney beans. When the size of regular food portions was taken into consideration, the best sources of total dietary fibre were peas and kidney beans (more than 11 g/serving). The same foods were the best sources of cellulose (4.98 and 3.56 g/serving) and resistant starch (3.90 and 2.83 g/serving). High intake of arabinoxylans and fructans could be accomplished with cooked wheat (3.20 g and 1.60 g/serving, respectively). Oat (1.39 g/serving) and barley flakes (1.30 g/serving) can be recommended as the best sources of beta-glucan.

The use of selenium as animal feed supplement in Serbia was approved in 1989 for some categories of pigs, sheep and poultry. From 2000 selenium in animal feed became a requirement for all categories of farm animals. The aim of this study was to determine the consumption of selenium by Serbian livestock and in poultry production between 1990-1991 and 2000-2008 and to analyze the selenium content of meat, milk and eggs sold on Serbian markets to gain insight into human selenium intake. Data indicate a low level of selenium inclusion in animal feed during 1990-1991 compared to during 2000-2008. These results coincide with Serbian regulations. From 2001 an organic form of selenium (selenized yeast) was introduced in small quantities (less than 8% of the total consumed selenium). Analysis of meat, milk and eggs from Serbian markets shows increased selenium levels compared to 1991. However, the estimated total human daily intake in Serbia is 40.9 μg, which is under the recommended quantity. Increasing the quantity of selenium included in animal feed and the substitution of inorganic selenium with selenized yeast could be beneficial for animal health and farm productivity. As a consequence a further improvement in the human selenium status in Serbia should be possible. Upotreba selena kao suplementa za stočnu hranu odobrena je u Srbiji 1989. godine za neke kategorija svinja, ovaca i živine. Od 2000. propisan je obavezan sadržaj selena u hrani za sve domaće životinje. Cilj rada bio je istraživanje upotrebe selena za suplementaciju stočne hrane selenom u periodima 1990-1991 i 2000-2008 i analiza sadržaja selena u namirnicama životinjskog porekla. Rezultati ukazuju na povećanu upotrebu selena kao aditiva za stočnu hranu od 2000. i povećan sadržaj selena u svinjskom mesu i jajima u poređenju sa podacima iz 1991. Procenjeni dnevni unos selena stanovnika Srbije je 40.9 μg što je značajno manje od preporučenog dnevnog unosa selena. Povećana upotreba selena u ishrani domaćih životinja, i zamena neorganskih jedinjenja selena seleniziranim kvascem, pored povoljnih efekata na zdravlje i produktivnost životinja, dovela bi do daljeg poboljšanja statusa selena stanovnika Srbije.

Researches conducted worldwide indicate a frequent deficiency in mineral matters. Due to the increased need during the period of accelerated growth and development, children belong to the group that is exposed to the highest risk of mineral matter deficiency. Our objectives were to determine the iron, zinc, copper, manganese, and calcium intake in the collective diet of the preschool population in the in the northwestern region of Bosnia- in the Republic of Srpska and to estimate the adequacy of the application of the international food composition tables for nutrition planning relating to mineral matters. Samples of food intended for children’s diet were collected in the preschool institution “Radost” (a kindergarten), in the city of Prijedor. In daily portions, Fe, Zn, Cu, Mn, and Ca contents were determined by flame atomic absorption spectrophotometry. Contents of mineral matters in daily meals were also calculated by the food composition tables. An average daily meal contained 2.86 mg of Fe, 1.71 mg of Zn, 0.19 mg of Cu, 0.21 mg of Mn, and 83.5 mg of Ca. With calculation method, contents of all minerals are significantly higher than the experimental data for all used food composition tables. The obtained results indicate a significant deficiency in mineral matters in the collective diet of the preschool population in the Republic of Srpska, a certain non-compliance with the applicable recommendations, and also suggest a need to create food composition tables for food being consumed in our region.

A 16-week experiment was conducted to compare effects of various levels of sodium selenite (SS) and Se-enriched yeast (SY), on the whole-egg Se content and hen's productivity. One hundred Shaver 579 hens, 27 weeks old, were placed on one of five experimental treatments. Each treatment was replicated four times with five hens per cage. Treatments consisted of feeding a low Se diet without supplementation (basal diet) or basal diet with one of two levels of supplemented Se (0.4 or 0.8 mg/kg) supplied by SS or SY. All supplemented treatments had significantly higher whole-egg Se concentration from basal diet (P lt 0.05). On the same supplemented level, hens fed on SY had higher egg Se content from hens feed on SS (P lt 0.001). No effects of dietary treatments on egg weight, percentages of dirty and cracked egg, and feed intake and conversion of feed were observed throughout the trial (P lt 0.05). In the first 8 weeks, there was no significant difference (P lt 0.05) in hen-day egg production among treatments. From the ninth week on to the end of the trial, supplementation of SY to hen's diet resulted in a higher egg production than SS (P lt 0.01).

Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form) and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC) method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ?C within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50?5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents), linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 ?g/ml to 2 ?g/ml, precision for the 0.05 ?g/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis), as well as linearity in a range that significantly superseded the expected content in the samples (r = 0.9994, and r = 0.99987). Hydrolysis procedures make a sample suitable for vitamin B2 determination. In the liver paste samples a high content of vitamin B2 was determined: 0.83 mg/100 g after acid hydrolysis, and 0.909 mg/100 g after acid-enzyme hydrolysis. There were statistically significantly higher values determined after the acid-enzyme hydrolysis (p < 0.05). Conclusion. Using acid-enzyme hydrolysis and separation instrument technique (liquid chromatography) with a fluorescent detector as detection system, statistically significantly greater vitamin B2 quantities were determined than after using acid hydrolysis procedure. Vitamin B2 content determined in ten liver paste samples was high (0.881 ? 0.936 mg/100g) indicating that this meat product is a good vitamin B2 source.

A 16-week-long experiment was performed to compare the effect of sodium selenite (SS) and selenium-enriched yeast (SY) supplementation on eggshell quality and also to evaluate breaking force correlation with other parameters of shell quality originating from hens fed with selenium supplementation. One hundred Shaver 579 hens (27 weeks old) with similar body size were randomly divided for five dietary treatments: basal diet without selenium supplementation and basal diets with two levels of selenium supplementation (0.4 or 0.8 mg/kg) via SS or SY. No adverse effect of Se inclusion in hen's feed, regardless of its source, on shell breaking force, shell deformation, shape index, shell thickness and shell percentage, were observed throughout the current study (P > 0.05). Moderate correlations were found between breaking force and nondestructive shell deformation for all diets (P (lt) 0.05). There was no significant overall correlation between egg breaking force and shell thickness or/and percentage shell in the presence of selenium supplemention (P > 0.05). Shape index in all four selenium-supplemented groups was not related to the breaking force (P > 0.05). Selenium supplementation of up to 0.8 mg/kg, regardless of its source, in the diet of laying hens in their first phase of laying does not adversely affect eggshell quality.

This study examined the influence of low, adequate and high dietary zinc intake on the growth and metabolic interactions between zinc, copper and iron in different Mongolian gerbil (Meriones unguiculatus) tissues. Animals were fed a basal diet (for 3 wk) containing a low-zinc level (8 mg/kg diet, LZ-group), adequate zinc level (25 mg/kg diet, AZ-group) and saturated zinc level (38 mg/kg diet, SZ-group). After comparing the body weight of gerbils, the present study demonstrated that the LZ-group (51.68 g ± 3.35) showed growth retardation, contrary to the AZ- and SZ-groups (58.03 g ± 2.18 and 62.35 g ± 2.04, respectively). Concentrations of zinc in the liver, kidneys and testes in the LZ-group (41.28, 19.58, 22.55 mg/kg, respectively) were significantly lower than in the AZ-group (57.27, 23.73, 28.79 mg/kg, respectively) and the SZ-group (73.06, 30.07, 34.52 mg/kg, respectively). Results also showed that copper and iron concentrations in the kidney, heart and liver were significantly higher in the LZ-group (Cu 11.45, 7.01, 7.95 mg/kg; Fe 116.19, 126.07, 299.47 mg/kg) than in the AZ-group (Cu 8.72, 5.6, 6.5 mg/kg; Fe 97.27, 97.27, 250.25 mg/kg) and the SZ-group (Cu 6.48, 4.15, 4.8 mg/kg; Fe 74.95, 77.95, 200.27 mg/kg). There was an increase of testis copper concentration in the LZ-group (4.9 mg/kg) compared to the AZ- and SZ-groups (3.99 and 3.05 mg/kg, respectively), and there was no significant difference in testis iron concentration between animals in different diet groups. These results showed that a low-zinc diet had negative effects on growth and the concentration of zinc in the kidneys, liver and testes. This also affected homeostasis of copper and iron by increasing its distribution in the kidneys, liver and heart tissue. However, in testes only copper concentration was increased.

Zinc is an important mineral that is required for normal bone development. However, the direct effects of zinc on the mineralization of bone cells of human origin are not clear. The objective of this study was to determine the effects of zinc on the differentiation of SaOS-2 human osteoblastlike cells and the formation of mineralized bone nodules. Cells were cultured for 8 d and then transferred to zinc-free medium and treated with varying concentrations (0-50 microM) of zinc. Alkaline phosphatase (ALP) activity was used as a measure of osteoblast differentiation, and bone nodules were detected by von Kossa staining. After 4, 6, and 8 d of treatment, zinc increased ALP activity at 1 and 10 microM, but decreased activity at 50 microM. After 9 d of treatment, zinc increased both the number and area of mineralized bone nodules at low concentrations (1 and 10 microM), but decreased both at higher concentrations (25 and 50 microM). These findings demonstrate that zinc has biphasic effects on the differentiation and mineralization of human osteoblast-like cells.

The aim of this work was to explore the effects of a low- and high-zinc diet and vitamin A on the distribution of fatty acids in chylomicrons. Mongolian Gerbils were fed a basal diet (for 3 wk) containing 8 or 38 mg zinc/kg of feed (low-zinc group [termed LZ group] and saturated zinc group [termed SZ group], respectively). The following day, the animals were given sunflower oil containing 50 nmol vitamin A. The results showed that the concentration of zinc in blood plasma was similar in both groups. The amount of plasma chylomicrons was lower in the LZ group than in the SZ group (p lt 0.001). The concentration of retinol in blood plasma was lower in the LZ group than in the SZ group (p lt 0.01). However, the results demonstrated an increase in the blood plasma retinol concentration in the LZ group compared to the SZ group when calculated per milligram of plasma chylomicrons (p lt 0.01). In plasma chylomicrons, fatty acids corresponding to 16:0, 16:1, 17:0, 17:1, 18:0, 18:1, 18:2, 18:3, 20:0, 21:0, and 20:4 were detected. The fatty acid distribution was similar in both groups. There was no major difference in the concentration of fatty acids in plasma chylomicrons between both experimental groups, except for 20:4 (a lower amount was found in the SZ group). Our results show that dietary zinc influences both the amount of chylomicrons in blood plasma and the concentrations of retinol and arachidonic acid in chylomicrons.

The effect of dietary zinc on the distribution of fatty acids in blood plasma chylomicrons was studied. The experiment was performed on male Mongolian Gerbils, fed ad libitum for 3 weeks with standard diet, containing 8 or 38 mg of Zn per kg of food (low zinc diet group, LZ, and saturated zinc diet group, SZ, respectivelly). At the 21st day gerbils were given sunflower oil by gavage. After 2.5 hours, blood was collected from abdominal vein, and samples were pooled (five animals per one sample). Chylomicron fractions were isolated by ultracentrifugation and mass of dried chylomicrons was measured. Fatty acid composition was analyzed by gas-liquid chromatography. Significantly higher amount of chylomicrons in blood plasma of SZ than in LZ group was found. In chylomicrons, following fatty acids were found: 16:0, 16:1, 17:0, 17:1, 18:0, 18:1, 18:2, 18:3, 20:0, 21:0 and 20:4. The amount of individual fatty acids in chylomicrons in both groups was similar, except 20:4 where lower amount in SZ group was found. Zinc diet did not affect fatty acid distribution in chylomicrons of both groups. Animals fed with zinc saturated diet had higher amount of fatty acids in blood plasma. Observed results suggest that dietary zinc influences the quantity of fatty acids absorption but not its distribution in chylomicrons. Ispitivan je efekat unosa dijetarnog cinka na distribuciju masnih kiselina u hilomikronima plazme. Eksperiment je rađen na mužjacima gerbila, hranjenim standardnom dijetom, ad libitum, u toku 3 nedelje hrana je sadržala 8 ili 38 mg cinka po kg hrane (grupa sa smanjenim unosom cinka, LZ i grupa sa povećanim unosom cinka, SZ, respektivno). Dvadeset prvog dana, životinjama je dato suncokretovo ulje sondom. Nakon 2,5 časa, krv je uzimana iz abdominalne vene i uzorci su pulovani (5 životinja za jedan uzorak). Hilomikronske frakcije su izolovane ultracentrifugiranjem i merena je masa suvih hilomikrona. Masnokiselinski sastav lipida u hilomikronima je određivan gasno-tečnom hromatografijom. Nađena je značajno veća količina hilomikrona u plazmi SZ grupe nego u LZ grupi. U hilomikronima su nađene sledeće masne kiseline: 16:0, 16:1, 17:0, 17:1, 18:0, 18:1, 18:2, 18:3, 20:0, 21:0 i 20:4. Zastupljenost pojedinačnih masnih kiselina u hilomikronima obe grupe bila je slična, izuzev za 20:4 gde je izmerena niža količina u SZ grupi. Ishrana cinkom ne utiče na distribuciju većine masnih kiselina u hilomikronima. Dobijeni rezultati ukazuju da cink utiče na metabolizam masti i to u delu formiranja hilomikrona, ali je uticaj ograničen na količinu formiranih hilomikrona, ali ne i distribuciju pojedinih masnih kiselina u hilomikronima.