• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.661-670
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• 2006

Selenium (Se) obtained from dietary sources including cereals, grains and vegetables is an essential micronutrient for normal function of the body. Plants convert Se into selenomethionine and incorporate it into proteins in place of methionine, while higher animals synthesize selenoproteins containing selenocysteine. Excessive Se in the body is methylated stepwise to methylated selenium metabolites from selenide. Both inorganic and organic forms of selenium can be the nutritional sources in human, and they are transformed to selenide and then the amino acid selenocysteine attached to a specific $tRNA^{ser(sec)}$. The selenocysteine (Sec) is incorporated into selenoprotein sequences by the UGA codon. The decoding of UGA as Sec requires specific mechanisms because UGA is normally read as a stop codon: cis-acting sequences in the mRNA (the selenocysteine insertion sequence, SECIS, within the 3'untranslated region) and trans -acting factors dedicated to Sec incorporation are required for incorporation of Sec during translation of selenoprotein mRNAs. Approximately 25 selenoproteins have been identified in mammals. Several of these, including glutathione peroxidases, thioredoxin reductases and selenoprotein P, have been purified or cloned, allowing further characterization of their biological function. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals which may contribute to the development of chronic disease such as cancer and heart disease. Other selenoproteins have important roles in regulation of thyroid function and play a role in the immune system. Daily selenium iatake was reported to be $42.0{\pm}16.9{\mu}g/day$ in Korean adult women. This review focuses on the metabolism and biological functions of selenium, and the nutritional status of selenium in the Korean population.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.91-96
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• 1994

This study was conducted to determine the effect of inorganic selenium (Se) sources on rumen bacterial yield, ruminal volatile fatty acid (VFA) production and total tract digestion of timothy hay (Phlewm pratense L.) in Japanese Corriedale wethers. A $3{\times}3$ Latin square design was used with three wethers, three periods and three treatments. In each period, there was 7 d dietary adjustment followed by 5 d total collection of urine and feces. Ruminal fluid samples were obtained at 0, 1, 3, 5 and 7 h postprandially on the final day of the collection period. The three dietary treatments were: (1) without Se supplementation (control); (2) with Se supplementation as sodium selenate; and (3) sodium selenite at a rate 0.2 mg Se/kg dietary DM. The basal diet was timothy hay fed at 2% of body weight/d. Results indicated that there was slight decrease in rumen bacterial yield of animal supplement with inorganic Se, however, differences over the control were insignificant. It was found that Se content of ruminal fluid was negatively correlated (p < 0.05) to rumen bacterial yield. The various VFA contents and acetate and propionate ratio of the different ruminal fluid samples were insignificant across treatment means and the same manner was observed to the different digestibilities (DM, OM, CP, NDF, ADF and NDS). This study concludes that Se supplementation at 0.2 mg Se/kg dietary DM either from sodium selenate or sodium selenite could not significantly influence rumen bacterial functions.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.435-444
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• 2003

In 1957, Schwarz and Foltz discovered that selenium (Se) was an essential trace mineral and nutritionists then started extensive studies to figure out the metabolic function of this element which has been called as toxic mineral. The discovery that glutathione peroxidase (GSH-Px) contained Se demonstrated a biochemical role for Se as an essential trace element. The major physiological function of Se containing GSH-Px is thought to maintain low levels of $H_2O_2$ and other hydroperoxides in the cell to prevent tissues from peroxidation damages. It is known that the GSH-Px activity is increased when animals were fed high dietary levels of Se. Chemical properties of Se have much in common with sulfur (S) therefore Se would follow the sulfur pathways in its metabolism in animal body. Two sources of Se are available for supplementation of Se in animal feed. Inorganic Se can also exist in selenide (-2), elemental (0), selenite (+4) and selenate (+6) oxidation state with other minerals. When sulfur in S containing amino acids is replaced by Se, organic Se can be made and named "eleno"prior to the name of S containing amino acid, i.e. selenomethionine. Selenium deficiency affects humans as well as animals and dysfunctions such as exudative diathesis, retained placenta, mastitis, liver necrosis, Keshan disease, numerous diseases and cancer. From several centuries ago, Se toxicity was recognized in various animal species and much of the current toxic Se levels has been established largely based upon the controlled toxicity studies used inorganic Se. Toxic effects of Se in animal result in reduced feed intake, growth retardation, ataxia, diarrhea, alopecia and sloughing of hooves. However, several experiments demonstrated that Se deficiencies or toxicities were varied by dietary Se levels and sources. Recent studies demonstrated that the incidence of colorectal and prostate cancer was reduced by approximately 50% when humans consumed 200 ${\mu}g$ of Se daily.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.117-126
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• 1987

The effect of selenium and vitamin E on the incidence of retained fetal membranes(RFM) was evaluated in dairy cows raised in Kyonggi-do province from July through September 1985. Sodium selenite(0.1mg/kg of body weight) and vitamin E (1,000 IU) were simultaneously injected 21 days prior to the expected calving day to Holstein cows and the incidence in the treated group was compared with that in the non-treated control group. Serum levels of selenium, vitamin E, calcium, inorganic phosphorus and magnesium were also determined in the treated and the non-treated groups to compare the status of vitamin E and other minerals during periparturient period in the cows with RFM and the normal ones. The incidence of RFM was 34.5% in cows of the non-treated group (29 heads), whereas it was significantly reduced to 9.7% in cows of the treated group (31 heads) (p<0.05). Data for serum mineral concentrations showed that the prepartal inorganic phosphorus concentration was significantly lower in the RFM than in the not-retained group(p<0.01). As a result, the prepartal Ca/P ratio was significantly higher in the RFM group(p<0.01). It appears that a single injection of 0.1mg of sodium selenite per kg body weight and 1,000 IU of vitamin E 21 days prior to the expected calving day is an effective prophylactic for prevention of RFM, and that RFM may be related to imbalances in calcium and phosphorus metabolism.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3817-3824
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• 2013

Various separation modes in HPLC, such as anion exchange (AE), reversed-phase (RP), and affinity (AF) chromatography were examined for the separation of selenium species in human blood serum and urine. While RP- and AE-HPLC were mainly used for the separation of small molecular selenium species, double column AF-HPLC achieved the separation of selenoproteins in blood serum efficiently. Further, the effluent of AF-HPLC was enzymatically hydrolyzed and then analyzed with RP HPLC for selenoamino acid study. The versatility of the hybrid technique makes the in-depth study of selenium species possible. For quantification, post column isotope dilution (ID) with $^{78}Se$ spike was performed. ORC ICP/MS (octapole reaction cell inductively coupled plasma/mass spectrometry) was used with 4 mL $min^{-1}$ Hydrogen as reaction gas. In urine sample, inorganic selenium and SeCys were identified. In blood serum, selenoproteins GPx, SelP and SeAlb were detected and quantified. The concentration for GPx, SelP and SeAlb was $22.8{\pm}3.4\;ng\;g^{-1}$, $45.2{\pm}1.7\;ng\;g^{-1}$, and $16.1{\pm}2.2\;ng\;g^{-1}$, respectively when $^{80}Se/^{78}Se$ was used. The sum of these selenoproteins ($84.1{\pm}4.4\;ng\;g^{-1}$) agrees well with the total selenium concentration measured with the ID method of $87.0{\pm}3.0\;ng\;g^{-1}$. Enzymatic hydrolysis of each selenium proteins revealed that SeCys is the major amino acid for all three proteins and SeMet is contained in SeAlb only.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.163-170
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• 2000

This study was conducted to examine the effects of recombinant Bovine Somatotropin (rBST), vitamin E(Vit. E) and selenium (Se) administration on the blood chemical values and hormone concentrations of serum in Hanwoo sires. Hanwoo sires were randomly assigned to five groups; 1) control, 2) rBST,0.09mg/kg body weight (BW), 3) Vit E, 1,500IU/kg BW, 4) Se 0.1mg/kg BW, 5) Vit E, 1,500IU plus Se 0.1mg/kg BW. rBST, Vit. E and Se for each experimental group were given 6 times at 15 days interval by intermuscular injection. Blood samples were collected ten times for experimental periods and separated the serum by centrifugation and stored into deep freezer. The concentration of albumin was the highest in Se group than those of any other groups (P＜0.05) and Vit. E plus Se group was significantly higher than in the control and rBST groups (P＜0.05). The concentrations of blood urea nitrogen (BUN) and creatinine were significantly higher in rBST group than any other groups (P＜0.05). The concentration of total protein in rBST, Se and Vit. E plus Se groups were significantly higher than in control group (P＜0.05). The concentrations of calcium, cholesterol,, glucose, inorganic phosphorus and triglycerides in serum were not difference in all experimental groups (P＞0.05). The concentration of estradiol was slightly higher in Se and Vit. E plus Se groups than those of any other groups, but not significantly difference among the experimental groups (P＜0.05). The concentration of testosterone was not affected by the administration of rBST, Vit. E and Se.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.52-59
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• 2007

The present study was designed to assess whether dietary inorganic and organic selenium (Se) could affect antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione-S-transferase (GST), and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in the intestine, serum, liver, and gastrocnemius muscle of Korean native goats. A total of eighteen Korean native goats was allotted into three dietary groups, consisting of basal diet (CON), or basal diet with either 0.25 ppm inorganic (IOSEL) or 0.25 ppm organic Se (ORSEL), and fed the corresponding diets for 5 wks. Growth performance, including body weight and total gain, and blood biochemical profiles, including GSH-Px, were not significantly different between the three dietary groups. Also, the specific activities of SOD, GSH-Px, and GST, and the level of MDA in the intestinal mucosa and liver from goats were not substantially affected by either inorganic Se or organic Se. However, goats fed the diet containing organic Se showed a significant increase in GSH-Px and GST activities in the gastrocnemius muscle compared with those fed the basal diet. In conclusion, increased muscle GSH-Px and GST activities suggest that dietary organic Se may affect, at least in part, the antioxidant defense system in muscle of Korean native goats under the conditions of our feeding regimen.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.281-289
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• 2013

This study was conducted to investigate the effects of feeding seleniferous whole crop barley silage (WCBS) on the growth performance, blood and carcass characteristics, and tissue selenium deposition infinishing Hanwoo steers. A total of 20 growing Hanwoo steers were selected and assigned to one of the following feed groups: control (0.1 ppm Se), T1 (0.3 ppm Se), T2 (0.9 ppm Se), and T3 (0.9 ppm of inorganic Se). Five steers were allocated to each treatment group, and the trial lasted for 90 days. All experimental diets combined seleniferous and/or non-seleniferous WCBS up to a ratio of 30%. For the T3 diet, 0.9 ppm Se in the form of sodium selenite was added to the control diet. Dietary level and type of selenium did not affect feed intake and body weight gain. Blood total lipid and triglyceride concentrations were significantly (p<0.05) lower in the T2 group than in control. Blood immunoglobulin G concentration increased significantly (p<0.05) with increasing levels of dietary selenium; concentrations were significantly (p<0.05) higher in T2 and T3 than in control. Blood selenium concentration was the highest (p<0.05) in T2. No significant difference was observed in dressing rate, ribeye area, marbling score, meat color and fat color. Further, no association was found between levels and chemical form of dietary selenium and quality and quantity of meat. To the contrary, tissue selenium content in kidney, liver, and hind leg increased significantly (p<0.05) with increasing levels of selenium; however, feeding inorganic selenium did not introduce a significant increase in tissue selenium content of finishing Hanwoo steers. The results indicated that the selenium present in seleniferous WCBS was an effectively absorbable selenium source, suitable for increasing tissue selenium content in beef. Approximately 100 g of hind leg muscle from steers fed on the T2 diet met approximately 69% of the recommended daily selenium requirements.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3362-3366
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• 2013

A simple and quick separation technique for selenite in natural water was developed using $TiO_2$@$SiO_2/Fe_3O_4$ nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the $TiO_2$ shell. The synthesized nanoparticles were used to separate selenite ($Se^{4+}$) in the presence of $Se^{6+}$ or selenium anions for the photocatalytic reduction to $Se^0$ atom on the $TiO_2$ shell, followed by magnetic separation using $Fe_3O_4$ nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.139-148
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• 2012

This study was conducted to investigate effects of feeding seleniferous whole crop barley silage (WCBS) on growth performance and blood characteristics in growing Hanwoo steers. A total of 20 growing Hanwoo steers, initially weighing on average 208.8 kg of body weight, were used and treatments were consisted of 1) controls : 0.1 mg/kg Se, 2) T1 : 0.3 mg/kg Se, 3) T2 : 0.9 mg/kg Se by combining seleniferous and/or non-seleniferous WCBS, and 4) T3 : 0.9 mg/kg Se of inorganic Se treatment. Five steers were allocated to each treatment, and the trial was lasted for 90 days. All experimental diets were included to 30% of combination of seleniferous and/or non-seleniferous WCBS, and in T3 diet, sodium selenite that corresponds to 0.9 mg/kg Se was added to control diets. Also, the diets were isonitrogenous and isocaloric among treatments. Dietary level and type of selenium did not affect feed intakes and daily gain, and blood glucose concentration was significantly (p<0.05) lower for controls than T1 and T2 treatments. Blood total lipid concentration was significantly (p<0.05) decreased with increasing levels of dietary selenium, and also that of T2 and T3 was significantly (p<0.05) lower than controls. LDL-cholesterol concentration was significantly (p<0.05) lower for treatments including dietary selenium than controls, and also blood triglyceride concentration was significantly (p<0.05) lower for T2 than controls. Overall, it was tended that feeding seleniferous WCBS or inorganic Se increased blood IgG concentration, and in the same dietary selenium levels, T2 treatment was higher for IgG than T3 group (p>0.05). Blood selenium concentration was significantly (p<0.05) increased by feeding increasing levels of seleniferous WCBS, but there was no significant difference between controls and T3 group. These results showed that feeding seleniferous WCBS to growing Hanwoo steers was responsible for saccharide and lipid metabolism, and in particular, it reduced their total lipid and blood LDL-cholesterol concentrations. Furthermore, selenium present in seleniferous WCBS rather than inorganic selenium was better available in intestinal absorption, and it might help to enhance immunity in growing and younger stages of Hanwoo steers.