Dietary Selenium Levels Research Articles

Toxic effects of excessive levels of dietary selenium in juvenile yellowtail kingfish (Seriola lalandi)

Abstract Selenomethionine (SeMet) was supplemented to a fishmeal-based diet to investigate the toxic effects of excessive levels of dietary selenium (Se) in juvenile yellowtail kingfish ( Seriola lalandi ). For 10 weeks, the fish were fed one of five experimental diets; a basal diet containing 2.31 mg/kg of inherent Se or diets supplemented with SeMet to provide 4.91, 9.58, 15.43 or 20.87 mg/kg of Se. The results showed that the fish muscle proximate composition, feed conversion ratio and survival were not sensitive to dietary Se treatments; and no histopathological lesions were observed in heart and intestine tissues of the fish. The Se concentrations in liver and muscle tissues showed a strong linear positive relationship with the levels of Se in diets. Fish when fed the basal diet exhibited Se deficiency symptoms including myopathy, reduced feed intake, glutathione peroxidase activity and growth; whereas those fed the diets containing ≥ 4.91 mg Se/kg did not. While fish fed the 15.43 mg Se/kg diet did not show any toxic effects, the 20.87 mg Se/kg diet caused histopathological changes in liver and spleen as well as reduced feed intake, growth, haematocrit and hepatosomatic index, indicating Se toxicity. In conclusion, Se levels in liver and muscle tissues can be used as effective indicators of dietary Se exposure and dietary Se level between 15.43 and 20.87 mg/kg may be a threshold level in juvenile yellowtail kingfish.

Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

Effects of Dietary Selenium and Training on Mitochondrial Function in Young Horses

IntroductionExercise training results in improved mitochondrial efficiency but it is unclear if dietary selenium level can further modify mitochondrial function.MethodsAmerican Quarter Horse yearlings (n = 20; mean ± SE 18 ± 0.2 months) balanced with regard to age and sex were randomly assigned to four dietary Se and exercise training treatments for 14 weeks: 0.1 mg Se/kg DM with (n = 5) or without (n = 5) training or 0.3 mg Se/kg DM with (n = 5) or without (n = 5) training. Trained horses were exercised 4 d/wk for 30 min/d. At week 14, all horses underwent a 2 hr, 27.5 km submaximal exercise test (SET). Permeabilized muscle fibers obtained from the gluteus medius of horses at rest were analysed for mitochondrial function via high resolution respirometry. Mitochondrial oxidative phosphorylation capacity with Complex I substrates was determined using the respiratory control ratio (RCR) of state 3 (with ADP) and state 2 (without ADP; leak respiration). Electron transport system capacity (ETSC) was determined by uncoupling phosphorylation and respiration using carbonyl cyanide p‐trifluoromethoxyphenylhydrazone. Cytochrome c oxidase (CCO) and citrate synthase (CS) activities were assessed in resting muscle samples obtained at week 0 and 14, and in response to the SET. Data were analysed using a mixed model ANOVA.ResultsLeak, state 3, ETSC, CS and CCO were higher (P<0.05) at wk 14 compared to wk 0 in all horses, but were not affected by training or Se level. Additionally, CS and CCO were unaffected by the SET.ConclusionsMitochondrial number (CS activity) and efficiency were unaffected by training and dietary Se level, but did increase over time, perhaps due to growth of horses. A more strenuous training protocol may be needed to induce mitochondrial adaptations.Ethical Animal ResearchThis project was approved by the Institute of Food and Agricultural Sciences Animal Care Committee at the University of Florida (approval number 016‐12ANS). Sources of funding: Partial financial support of this project was provided by Alltech, Nicholasville, KY, USA. Competing interests: none.

Effect of different sources and levels of selenium on performance, meat quality, and tissue characteristics of broilers

The objective of this study was to evaluate the effects of dietary levels of inorganic and organic selenium (Se) on performance, meat physicochemical characteristics, and Se deposition in the tissues of broilers chickens. A total of 2,880 one-day-old broilers (Cobb 500 strain) were divided into 96 experimental pens of 30 birds each. The 12 experimental treatments were arranged in a factorial design of 4 × 3 [selenium levels of 0.15, 0.30, 0.45, and 0.60 ppm, and organic (selenium yeast, SY) or inorganic (sodium selenite, SS) sources of selenium and their association (SY + SS)], with 8 replicates in a completely randomized design. No differences (P > 0.05) among Se levels or sources were detected with regard to any performance parameters. The average values of ADFI, ADG, and FCR were 106 g/bird per day, 63 g/bird per day, and 1.684 kg/kg, respectively. No differences (P > 0.05) were found between treatments regarding pH (5.79) and shear force (30.08 kgf). Those birds receiving 0.15 ppm of Se showed a significantly higher (21.92%) cooking loss of breast meat (P < 0.05). The organic form of Se decreased cooking loss, and the smallest loss was found when the diet was supplemented with 0.60 ppm of Se (15.87%). Deposition of Se in the liver increased from 0.97 (0.15 ppm of Se) to 2.43 mg/kg (0.60 ppm of Se) when using SY. The concentration of Se in the breast meat increased linearly from 0.23 to 1.42 mg/kg with increasing dietary levels of SY. Therefore, dietary supplementation with 0.15 ppm of Se, independent of source, can maintain normal bird performance. The SY was more efficient in depositing Se to the liver and breast muscle than the SS.

Dietary Content and Type of Lipids and Selenium Supplement on Fatty Acid Profile in Meagre (Argyrosomus regius)

Dietary Content and Type of Lipids and Selenium Supplement on Fatty Acid Profile in Meagre (Argyrosomus regius)

셀레늄 강화 청보리 사일리지 급여가 비육기 거세한우의 생산성, 혈액성상 및 도체특성과 조직 내 셀레늄 축적에 미치는 영향

본 연구는 다양한 수준의 셀레늄 강화 청보리 사일리지와 무기셀레늄을 급여 시 비육기 거세한우의 생산성, 혈액 성상, 도체특성 및 조직 내 셀레늄 축적에 미치는 영향을 조사하였다. 시험은 거세비육우 20두를 공시하였고, 처리구는 셀레늄 수준에 따라 0.1 ppm Se(대조구), 0.3 ppm Se (T1), 0.9 ppm Se (T2) 및 무기셀레늄 0.9 ppm Se (T3) 급여구로 4처리를 나누어 처리구 구당 5두씩 완전임의 배치하여 90일간 사양시험을 실시하였다. 각 시험사료는 셀레늄 강화 및 셀레늄 무처리 관행 청보리 사일리지를 조합하여 건물기준 30% 함유하도록 배합하였다. 실험사료 내에 셀레늄 강화수준은 사료섭취량과 증체에 영향을 미치지 않았고, 혈중 총 지질과 중성지방농도는 대조구보다 T2구가 유의하게 낮았다(p<0.05). 혈중 면역글로불린은 셀레늄함유량이 많을수록 높게 나타나 T2와 T3구가 대조구보다 유의하게 높았다(p<0.05). 혈중 셀레늄농도는 유기태 셀레늄을 0.9 ppm 급여한 T2구가 가장 높았다(p<0.05). 도체율, 배최장근, 등지방두께, 근내지방도, 육색 및 지방색은 셀레늄급여로 인한 효과가 나타나지 않았다. 또한, 사료 내 셀레늄 수준 및 형태는 육질 및 육량등급 간에 관련성이 형성되지 않았다. 신장, 간장 및 후지 내 셀레늄 함량은 사료 내 셀레늄 강화수준이 증가함에 따라 유의하게 직선적으로 증가하였고(p<0.05), 무기셀레늄급여는 대조구와 유의한 차이가 나타나지 않아, 조직 내 셀레늄함량 증가에 도움이 되지 않았다(p>0.05). 이상의 결과에서 셀레늄 강화 청보리 사일리지 내 존재하는 셀레늄은 조직 내 셀레늄함량을 증가시키기에 유효한 셀레늄급원인 것으로 나타났고, 셀레늄 강화 청보리 최고수준(0.9 ppm Se)으로 급여하여 생산된 한우 후지육 100 g에 함유되어 있는 셀레늄은 성인기준 1일 최소 셀레늄 권장량(<TEX>$40{\mu}g$</TEX>)의 약 69%를 충족시키는 것으로 조사되었다. 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.

Influence of dietary magnesium and selenium levels in finishing diets on growth performance and carcass meat quality of feedlot Pelibuey lambs

Abstract. The objective of this study was to evaluate the influence of supplemental dietary selenium (Se) and magnesium (Mg) on feedlot lambs. Sixty-four male lambs were randomly distributed to the following treatments: 1) low level of Mg and Se: diet with 0.18% of Mg and 0.1 μg Se/g, 2) with supplementation of magnesium oxide (MgO): diet with 0.32% of Mg and 0.1 μg Se/g, 3) with supplementation of Sodium selenite (Na2SeO3): diet with 0.3 μg Se/g and 0.18 % of Mg, 4) With supplementation of MgO and Na2SeO3: diet with 0.32% of Mg and 0.3 μg Se/g. There were no differences (P&gt;0.05) in the average daily gain and feed conversion but Se supplement with Na2SeO3 (0.3 μg Se/g) enhanced dry matter intake, dressing percentage (P&lt;0.05) and leg muscle weight (P&lt;0.02). The average values of the water retained potential, coordinate L, a, and sensory analysis were different with Se (P&lt;0.05). Magnesium suplemented as inorganic source (0.32% of Mg) enhanced (P&lt;0.05) some characteristics in sensorial meat analysis.

Translational Redefinition of UGA Codons Is Regulated by Selenium Availability

Incorporation of selenium into ~25 mammalian selenoproteins occurs by translational recoding whereby in-frame UGA codons are redefined to encode the selenium containing amino acid, selenocysteine (Sec). Here we applied ribosome profiling to examine the effect of dietary selenium levels on the translational mechanisms controlling selenoprotein synthesis in mouse liver. Dietary selenium levels were shown to control gene-specific selenoprotein expression primarily at the translation level by differential regulation of UGA redefinition and Sec incorporation efficiency, although effects on translation initiation and mRNA abundance were also observed. Direct evidence is presented that increasing dietary selenium causes a vast increase in ribosome density downstream of UGA-Sec codons for a subset of selenoprotein mRNAs and that the selenium-dependent effects on Sec incorporation efficiency are mediated in part by the degree of Sec-tRNA([Ser]Sec) Um34 methylation. Furthermore, we find evidence for translation in the 5'-UTRs for a subset of selenoproteins and for ribosome pausing near the UGA-Sec codon in those mRNAs encoding the selenoproteins most affected by selenium availability. These data illustrate how dietary levels of the trace element selenium can alter the readout of the genetic code to affect the expression of an entire class of proteins.

The effect of different dietary levels of vitamin E and selenium on antioxidant status and immunological markers in serum of laying hens

The effect of different dietary levels of selenium (Se) and vitamin E on egg production, the antioxidant status and the immune system response of hens was investigated in the current study. A total of 32 Lohman Brown hens were divided into four groups and were fed diets with 5% of soybean oil and two levels of Se (0.15 and 0.30 mg/kg) and vitamin E (30 and 60 mg/kg). During 10 weeks of experimental feeding, the body weights of hens and egg production were similar in all dietary treatments, but a higher Se content of diets contributed to a significant increase in egg weight. A higher vitamin E level significantly increased alpha-tocopherol concentrations (2.71 vs. 2.05 microg/mL, p = 0.001), superoxide dismutase (SOD) activity (43.3 vs. 39.9 U/mL, p = 0.049) and the ferric reducing ability of serum (FRAP) (123.0 vs. 105.7 micromol/L, p = 0.029). A higher Se content increased the concentrations of ascorbic acid (0.309 vs. 0.073 microg/L, p = 0.001), retinol (1.48 vs. 1.15 microg/mL, p = 0.001) and alpha-tocopherol (2.86 vs. 1.90 microg/mL, p = 0.001), the activity levels of catalase (3.40 vs. 2.98 U/L,p = 0.010) and SOD (43.4 vs. 30.8 U/mL, p = 0.040) as well as the total antioxidant status (TAS) of serum (0.38 vs. 0.28 mmol/L, p = 0.026). There were no significant differences in the concentrations of tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6) between treatments, while a higher vitamin E content of diets increased serum immunoglobulin A (IgA) concentrations (370.6 vs. 321.3 microg/mL, p = 0.026). Higher dietary levels of vitamin E and Se increased the serum concentrations of retinol (1.66 vs. 2.20 microg/mL, p = 0.013) and a-tocopherol (3.33 vs. 1.71, p = 0.014), but they had no effect on the other physiological parameters. It is recommended that the levels of both supplements, Se and vitamin E, be increased in laying hen diets as they have a beneficial effect on the serum concentrations of retinol and alpha-tocopherol.

Effects of dietary level of selenium and grain on digestive metabolism in lambs

The objective was to evaluate the effect of different levels of selenium with two levels of grain corn in the diets on ruminal, postruminal, and total tract digestion of nutrients, ruminal fermentation characteristics, and selenium balance in lambs. A split-plot design was used in four periods with repeated Latin square using eight Suffolk &amp;times; Dorset male lambs with four levels of selenium (sodium selenite, Na&lt;sub&gt;2&lt;/sub&gt;SeO&lt;sub&gt;3&lt;/sub&gt;), without adding selenium, 0.3, 0.6, and 0.9 mg of selenium/kg dry matter (DM) with 70 and 50% of corn grain in the diet. The four selenium levels affected organic matter as follows: starch, neutral detergent fibre, nitrogen and selenium excretion; selenium ruminal digestion; organic matter, neutral detergent fibre, nitrogen and selenium postruminal digestion; and organic matter, neutral detergent fibre, nitrogen and selenium total tract digestion (P &amp;lt; 0.05). Starch and organic matter flow decreased with 0.6 and 0.9 mg of selenium with the 70% grain diet (P&amp;nbsp;&amp;lt; 0.05). Selenium flow increased linearly with selenium levels (P &amp;lt; 0.01) with both levels of grain. Selenium supplementation increased linearly selenium concentration in ruminal fluid (P &amp;lt; 0.01), but did not affect other ruminal characteristics. Also, selenium absorption and retention was increased by selenium concentrations (P&amp;nbsp;&amp;lt; 0.01). The apparent absorption of selenium increased (31%, P &amp;lt; 0.01) with the 70% grain diet. In conclusion, the high content of nonstructural carbohydrates improved the availability of selenium and 0.9 mg of selenium/kg &lt;br /&gt;DM improved the absorption and availability of selenium. &amp;nbsp;

Chicken meat nutritional value when feeding red palm oil, palm oil or rendered animal fat in combinations with linseed oil, rapeseed oil and two levels of selenium.

Chicken meat nutritional value with regard to fatty acid composition and selenium content depends on the choice of dietary oil and selenium level used in the chickens’ feed. The objective of this study was to investigate the effect of replacing commonly used rendered animal fat as a dietary source of saturated fatty acids and soybean oil as a source of unsaturated fatty acids, with palm oil and red palm oil in combinations with rapeseed oil, linseed oil and two levels of selenium enriched yeast on chicken breast meat nutritional value. The study also wished to see whether red palm oil had a cholesterol lowering effect on chicken plasma.204 male, newly hatched broiler chickens were randomly divided into twelve dietary treatment groups, and individually fed one out of six dietary fat combinations combined with either low (0.1 mg Se /kg feed) or high (1 mg Se/kg feed) dietary selenium levels. Linseed oil, independent of accompanying dietary fat source, lead to increased levels of the n-3 EPA, DPA and DHA and reduced levels of the n-6 arachidonic acid (AA). The ratio between AA/EPA was reduced from 19/1 in the soybean oil dietary groups to 1.7/1 in the linseed oil dietary groups. Dietary red palm oil reduced total chicken plasma cholesterol levels. There were no differences between the dietary groups with regard to measured meat antioxidant capacity or sensory evaluation. Chicken meat selenium levels were clearly influenced by dietary selenium levels, but were not influenced by feed fatty acid composition. High dietary selenium level lead to marginally increased n-3 EPA and higher meat fat % in breast muscle but did not influence the other LC PUFA levels. Chicken breast meat nutritional value from the soybean oil and low selenium dietary groups may be regarded as less beneficial compared to the breast meat from the linseed oil and high selenium dietary groups. Replacing rendered animal fat with palm oil and red palm oil had no negative effects on chicken muscle nutritional value with regard to fatty acid composition. Red palm oil decreased total chicken plasma cholesterol, confirming the cholesterol reducing effect of this dietary oil.

Selenium and selenoprotein deficiencies induce widespread pyogranuloma formation in mice, while high levels of dietary selenium decrease liver tumor size driven by TGFα.

Changes in dietary selenium and selenoprotein status may influence both anti- and pro-cancer pathways, making the outcome of interventions different from one study to another. To characterize such outcomes in a defined setting, we undertook a controlled hepatocarcinogenesis study involving varying levels of dietary selenium and altered selenoprotein status using mice carrying a mutant (A37G) selenocysteine tRNA transgene (TrsptG37) and/or a cancer driver TGFα transgene. The use of TrsptG37 altered selenoprotein expression in a selenoprotein and tissue specific manner and, at sufficient dietary selenium levels, separate the effect of diet and selenoprotein status. Mice were maintained on diets deficient in selenium (0.02 ppm selenium) or supplemented with 0.1, 0.4 or 2.25 ppm selenium or 30 ppm triphenylselenonium chloride (TPSC), a non-metabolized selenium compound. TrsptG37 transgenic and TGFα/TrsptG37 bi-transgenic mice subjected to selenium-deficient or TPSC diets developed a neurological phenotype associated with early morbidity and mortality prior to hepatocarcinoma development. Pathology analyses revealed widespread disseminated pyogranulomatous inflammation. Pyogranulomas occurred in liver, lungs, heart, spleen, small and large intestine, and mesenteric lymph nodes in these transgenic and bi-transgenic mice. The incidence of liver tumors was significantly increased in mice carrying the TGFα transgene, while dietary selenium and selenoprotein status did not affect tumor number and multiplicity. However, adenoma and carcinoma size and area were smaller in TGFα transgenic mice that were fed 0.4 and 2.25 versus 0.1 ppm of selenium. Thus, selenium and selenoprotein deficiencies led to widespread pyogranuloma formation, while high selenium levels inhibited the size of TGFα–induced liver tumors.

셀레늄함유 청보리 급여가 거세비육돈의 생산성, 혈액 및 도체특성, 조직 내 셀레늄 축적에 미치는 영향

본 연구는 증가하는 수준의 셀레늄함유 청보리 사료를 비육돈에 급여 시 비육돈의 생산성, 혈액성상, 도체형질 및 조직 내 셀레늄함량에 미치는 영향을 조사하였다. 시험은 거세비육돈 40두를 공시하였고, 처리구는 셀레늄 수준에 따라 4처리구(0.1 ppm(대조구), 0.2 ppm, 0.4 ppm, 0.6 ppm)로 나누어 처리구당 5 pen씩, pen당 2두씩 배치하여, 6주간 사양시험을 실시하였다. 각 시험사료는 셀레늄 함유 및 셀레늄무시비 관행 청보리를 조합하여 배합비의 5%를 배합하였고, 조단백질 및 가소화에너지 함량은 처리구 간 유사하도록 배합하였다. 실험사료 내에 셀레늄함유 청보리의 수준증가는 사료섭취량과 증체에 영향을 미치지 않았고, 혈중 총지질 농도는 셀레늄 수준이 증가할수록 유의하게 낮아졌으며(p<0.05), 혈중 총콜레스테롤은 대조구가 0.4와 0.6 ppm 셀레늄 시험구보다 유의하게 높았다(p<0.05). 혈중 중성지방농도는 사료내 셀레늄수준이 증가함에 따라 유의하게 낮아졌고(p<0.05). 혈중 면역글로블린 G와 셀레늄 농도는 사료 내 셀레늄수준이 증가함에 따라 유의적으로 증가하였다(p<0.05). 도체율, 등지방 두께, 육량 및 육질등급은 셀레늄급여로 인한 효과가 나타나지 않았다. 신장, 간장 및 등심 내 셀레늄함량은 사료 내 셀레늄함유 청보리 급여수준이 증가함에 따라 유의하게 직선적으로 증가하였다. 이상의 결과에서 셀레늄함유 청보리급여는 비육돈의 지질대사관련 혈액성상을 개선시켰고, 셀레늄강화 돈육의 생산이 가능하였다. 본 연구에서 조직 내 셀레늄수준을 강화시키기 위한 사료내 적정셀레늄수준은 0.4 ppm인 것으로 나타났고, 생산된 돈육 등심 100 g이 소비자에게 제공되었을 때, 세계보건기구(WHO, 1996)에서 제안한 성인기준 1일 최소셀레늄권장량(40 <TEX>${\mu}g$</TEX>)이 충족되는 것으로 나타났다. The present study has been conducted to investigate the effects of feeding seleniferous whole crop barley (WCB) to finishing pigs on their growth performance, blood and carcass characteristics as well as on tissue selenium deposition. A total of 40 cross-bred barrows ((Landrace<TEX>${\times}$</TEX>Yorkshire)<TEX>${\times}$</TEX>Duroc) were allotted to five replicates of four treatments. Each replicate was arranged to 2 pigs per pen; the experimental period lasted for 6 weeks. The finishing pigs were fed diets containing 0.1 (non-seleniferous WCB as a control), 0.2, 0.4 and 0.6 ppm of selenium (Se) by supplementing the diets with seleniferous WCB. The isonitrogenous and isocaloric diets containing 5% non-seleniferous or seleniferous WCB were formulated. Feeding seleniferous WCB did not affect (p<0.05) the feed intake and BW gain. Total blood lipid concentration was significantly (p<0.05) decreased with increasing Se levels. Total blood cholesterol concentration for the control was significantly (p<0.05) higher than that for 0.4 and 0.6 ppm of Se treatments. Increasing the Se levels in WCB significantly (p<0.05) decreased blood triglyceride concentration; however, the levels increased immunoglobulin G and selenium concentrations. Feeding seleniferous WCB did not affect the carcass rate, backfat thickness and meat quality as well as yield grades. The Se concentration in the kidney, liver and loin were significantly (p<0.05) increased with increasing levels of seleniferous WCB. The results indicated that feeding seleniferous WCB may improve the blood characteristics related to lipid metabolism and thus, could produce selenium-fortified pork. Moreover, it is shown that the dietary optimal selenium level to depose selenium in porcine tissues by utilizing seleniferous WCB would be 0.4 mg of Se/kg of ration. Moreover, when 100 g of pork produced from pigs raised under such condition is served to consumers, it meets the minimum recommended daily requirements (40 <TEX>${\mu}g$</TEX>) of dietary selenium proposed by the World Health Organization (1996).

셀레늄함유 청보리 사일리지급여가 육성기 거세한우의 생산성 및 혈액성상에 미치는 영향

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 (p0.05). Blood selenium concentration was significantly (p

Dietary selenium and major depression: a nested case-control study

Alterations in redox biology are established in depression; however, there are no prospective epidemiological data on redox-active selenium in depression. We aimed to determine if low levels of dietary selenium are associated with an increased risk for de novo major depressive disorder (MDD). In this nested case-control study, women aged 20 years or more were identified from a randomly selected cohort being followed prospectively for the Geelong Osteoporosis Study. Cases were individuals with incident MDD, identified using the Structured Clinical Interview for DSM-IV-TR (SCID-I/NP); controls had no such history. Dietary selenium intake was measured using a food frequency questionnaire at baseline, together with anthropometric and lifestyle measures. Eighteen women who developed de novo MDD were classified as cases; there were 298 controls. Low dietary selenium intakes increased the likelihood of developing MDD; OR 2.74 (95%CI 0.95-7.89). After adjusting for age and SES, compared with a high selenium intake, a low intake (<8.9 μg/MJ/day) was associated with an approximate trebling of the likelihood for developing de novo MDD; OR 2.95 (95%CI 1.00-8.72). Smoking, alcohol consumption and physical activity did not confound the association. These data suggest that lower dietary selenium intakes are associated with an increased risk of subsequent de novo MDD. We propose that selenium's function as an antioxidant, and as a constituent of selenoproteins that are important in redox homeostasis, warrants further investigation as a risk factor for depression, and suggest a potentially novel modifiable factor in the primary prevention and management of depression.

Dietary selenium requirement and its toxicity in juvenile abalone Haliotis discus hannai Ino

A study was conducted to evaluate the effects of dietary selenium (Se) on survival, growth performances and immune responses of juvenile abalone Haliotis discus hannai. Moreover, the toxicity of high dose of dietary selenium was also analyzed. Six semi-purified diets containing graded levels of sodium selenite (0.15, 0.53, 0.88, 1.55, 2.63 and 9.16mgSe/kg diet) were randomly fed to juvenile abalone (initial weight: 0.68±0.00g) in triplicate groups for 24weeks in a flow-through system. Results showed that the weight gain ratio (WGR, %) of abalone fed 1.55mg/kg of dietary selenium was significantly (P<0.05) higher than that with 9.16mg/kg of dietary selenium. However, there were no significant (P>0.05) differences when compared to the other treatments. Selenium concentration in the soft body and the activity of glutathione peroxidase in serum were significantly (P<0.05) increased with dietary selenium. Significant higher activities of phenoloxidase (PO) and lysozyme in serum were observed in the treatment with 0.88mgSe/kg diet, compared with those in 9.16mgSe/kg diet. However, the protein concentration in serum maintained relatively constant regardless of dietary treatments. The dietary selenium requirement of juvenile abalone was estimated to be 1.408mg/kg, using second-order polynomial regression analysis. The toxicity of high level of dietary selenium (9.16mg/kg) to juvenile abalone was characterized by depressed growth performances and decreased activities of PO and lysozyme in serum.

Effect of dietary selenium level on growth performance, body composition and hepatic glutathione peroxidase activities of largemouth bassMicropterus salmoide

An 8-week growth trial was conducted to determine the effect of dietary selenium (Se) level on growth performance, body composition and hepatic glutathione peroxidase (GPx) activities of largemouth bass. Sodium selenite was added to the fish meal basal diet at 0, 0.2, 0.4, 0.6, 0.8 and 1.0 mg kg−1 Se providing 0.97, 1.17, 1.42, 1.60, 1.85 and 2.06 mg Se kg−1 diet respectively. Each diet was fed to triplicate groups of fish (initial mean body weight: 4.95 ± 0.03 g) in a closed indoor recirculating system. The Se concentration in the rearing water was not detectable during the whole experimental period. The highest weight gain was obtained in fish fed diets with 1.60 mg Se kg−1, which was significant higher (P 0.05) with the other treatments. Feed conversion ratio, protein efficiency ratio, protein productive value, apparent digestibility coefficients of dry matter and muscle composition were not significantly impacted (P > 0.05) by dietary treatments. Fish fed diets with ≥1.42 mg Se kg−1 obtained higher liver lipid contents than treatments with lower dietary Se levels. Hepatic malondialdehyde (MDA) was unchanged (P > 0.05) in relation to dietary Se concentration. Hepatic GPx and glutathione reductase (GR) activities markedly increased and decreased (P < 0.05) with increasing dietary Se concentration, respectively, and both reached a plateau with ≥1.85 mg Se kg−1. Based on growth performance, hepatic MDA and enzymatic responses of GPx and GR, the highest Se concentration (2.06 mg kg−1) employed in our study was not harmful for largemouth bass, and the optimal dietary level should be 1.60–1.85 mg Se kg−1 from sodium selenite, at a dietary vitamin E level of 400 IU kg−1.

The effect of dietary selenium levels on growth performance, antioxidant capacity and glutathione peroxidase 1 (GSHPx1) mRNA expression in growing meat rabbits

This study investigated the effect of different levels of dietary selenium (Se) on growth performance, antioxidant capacity and mRNA expression of glutathione peroxidase 1 (GSH-Px1) gene of meat rabbits from weaning to 2 months. A total of 120 growing rabbits that weaned at 30 days were randomly divided into five groups according to average body weight, with 24 rabbits in each group. Each group was fed with a diet containing 0.08, 0.24, 0.41, 0.59 and 0.70 Se mg/kg diet (dry matter (DM) basis), respectively. There was a 7-day adaptation period and a 23-day experimental period. The results showed that the dietary Se levels affected the average daily gain (ADG, P=0.0025) and the feed/gain ratio (F/G, P=0.0064). Deposition of Se in the liver increased with Se intake (P<0.0001). The dietary Se levels affected glutathione peroxidase activity (GSH-Px, P<0.0001), superoxide dismutase activity (SOD, P=0.0465), total antioxidant capacity (T-AOC, P=0.0406), malondialdehyde concentration (MDA, P=0.0004) and the expression of GSH-Px1 gene (P<0.0001) in the liver. A linear effect of dietary Se levels on the catalase (CAT) activity in the liver was obtained (P=0.0088). The dietary Se levels affected the serum GSH-Px and CAT activities (P=0.0124, 0.0156, respectively). There were no differences (P>0.05) on the serum SOD activity, T-AOC and MDA concentration among the treatments. It is concluded that optimal level of dietary Se for growth and antioxidative parameter in meat rabbits from weaning to 2 months is 0.24–0.41mg/kg DM.

Influence of dietary l-selenomethionine exposure on growth and survival of juvenile Huso huso

The influence of different levels of dietary selenium in juvenile Huso huso was investigated in an 8 week growth trial. The present study was conducted at the International Sturgeon Research Institute with the objective to determine the effects of dietary selenium on growth, survival and whole body proximate composition. Six experimental diets were prepared by adding dietary concentrations of 0, 5, 10, 20, 40 and 80 μg g−1 diet selenium in the form of l-selenomethionine (SeMet) resulting in dietary concentrations of 1.26, 2.44, 3.01, 5.37, 11.56 and 20.26 μg Se g−1 diet on a dry weight basis. Juvenile H. huso with a mean weight of 3.5 ± 2.0 g and mean total length of 8.5 ± 2.5 cm were obtained from the Shahid Marjani hatchery and acclimated to formulated diets for 20 days, after which the fish were divided into six experimental groups and moved to 18, 500-L tanks with 13 fish per tank in a completely randomized design and fed diets supplemented with selenium. Three replicates were used for each experimental group. A one way anova and the correlations analysis were used to determine the relationship between the data at 95% confidence interval by spss software for windows (ver.14.0) and the means were compared using the Duncan’s Multiple Range Test. After 8 weeks mean survival rate was 75 ± 9% across all groups. Comparison of results showed that although good growth was observed in all groups, H. huso in experimental groups 4 and 5 fed above 11 μg Se g−1 diet showed faster and higher growth rates. No significant differences were observed among the hematological parameters studied. Selenium accumulated in all tissues studied in a dose dependent manner with highest levels observed in the liver. Results obtained showed that selenium had no histopathological effects on the tissues studied. It is evident from the results of this study that dietary concentrations of selenium between 11.56 and 20.26 μg Se g−1 diet can be considered the threshold dietary concentrations for suitable growth in juvenile H. huso. Further research is required to study the interactive effects of Se with other chemical and physical stressors in order to establish suitable supplementary levels of selenium to increase immune response and disease resistance in H. huso.

Influence of dietary selenium level on the concentration of conjugated linoleic acid isomers, other fatty acids and amino acids in the liver and femoral muscles of rats

The purpose of the present study was to determine the influence of diets containing conjugated linoleic acid isomers (CLAmix) with or without low (&lt;sub&gt;L&lt;/sub&gt;Se) or high (&lt;sub&gt;H&lt;/sub&gt;Se) concentration of selenised yeast (SeY) on body weight gain (BWG), feed conversion efficiency (FCE), and concentrations of CLA isomers and other fatty acids (FA) in the liver and femoral muscle of rats. The investigation was performed on 48 female rats (Wistar, Hsd Brl Han: WIST), aged 8 weeks with an initial body weight of 195.7 &amp;plusmn; 0.8 g. After one week of submaintenance feeding, for 6 weeks the rats were fed ad libitum the Labofeed H diet supplemented with 1.5% CLAmix with or without low (0.2 &amp;mu;g Se/g diet) or high (0.5 &amp;mu;g Se/g diet) concentration of Se as SeY. The diet enriched with &lt;sub&gt;L&lt;/sub&gt;Se or &lt;sub&gt;H&lt;/sub&gt;Se elevated the BWG of rats compared with the control group, while the &lt;sub&gt;L&lt;/sub&gt;Se diet resulted in the most efficient increase in BWG. The diet containing CLAmix, irrespective of the presence of SeY, stimulated the accumulation of Se in the liver and muscles in comparison with the diet enriched with SeY. The addition of SeY to the diet enriched with CLAmix stimulated the accumulation of cis9trans11 (c9t11), t10c12 and cc isomers of CLA in the liver. The diet containing CLAmix and LSe most efficiently increased the concentration of these CLA isomers in muscles. The diets enriched with SeY increased the concentration of essential, endogenous and total amino acids (AA) in the liver, whereas the diets enriched with SeY or CLAmix reduced the concentration of these AA in muscles. The diets enriched with CLAmix and/or SeY decreased the &amp;Delta;9-desaturase index in the liver and muscles compared with the control group. These diets increased &amp;Delta;4-, &amp;Delta;5- and &amp;Delta;6-desaturase indexes in muscles, but significantly reduced the elongase index compared with the control group. Our study shows that dietary CLAmix increased the concentration of C14:0, C18:0 and the sum of saturated FA (SFA) in the liver, whereas the diets enriched with SeY, irrespective of the presence of CLAmix, slightly reduced the concentration of C14:0, C18:0, and SFA in muscles compared with the control group. The diets containing SeY and/or CLAmix increased the accumulation of arachidonic acid (ArA), linolenic acid (&amp;alpha;LNA) and c4c7c10c13c16c19C22:6 in the liver compared with the control rats. Negative effects of dietary SeY and/or CLAmix on the accumulation of &amp;alpha;LNA, c5c8c11c14c17C20:5, c7c10c13c16c19C22:5, c4c7c10c13c16c19C22:6, linoleic acid, ArA and c8c11c14C20:3 in muscles were found out. The CLAmix diet increased the &amp;Delta;4-, &amp;Delta;5-desaturase and elongase indexes in the liver. It also increased the &amp;Delta;4-, &amp;Delta;5- and &amp;Delta;6-desaturase indexes in muscles, but significantly reduced the elongase index compared with the control group. The finding that the diet with CLAmix and &lt;sub&gt;H&lt;/sub&gt;Se fed to rats decreased total FA and most efficiently increased the content of Se and essential AA in muscles is valuable information for nutritionists carrying out research on farm animals to improve the nutritive value of food from the aspect of human health.