Se Yeast Research Articles

Effect of dietary selenium yeast supplementation on porcine circovirus type 2 (PCV2) infections in mice.

The present study was performed to determine the protective role of dietary selenium (Se) yeast supplementation in porcine circovirus type 2 (PCV2) infected mice. Forty-eight Kun Ming female mice were randomly assigned to Se yeast group (0.3%Se +basal diet, n = 24) and control group (basal diet, n = 24). After 3 days of adaptive feeding and 15 days treatment with the experimental feed, mice were challenged by intraperitioneal injection of PCV2 at the dosage of 2000 TCID50 (50% tissue culture infection dose, TCID50). Serum total superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and interleukin-1 beta (IL-1β) levels were measured at 5, 10, 15, 20 days post infection (dpi). The PCV2 virus load in the liver, spleen and lung, and the microscopic lesions in the liver, spleen and lung also were determined on 5, 10, 15, and 20 dpi. Dietary Se yeast supplementation decreased (Pμ0.05) the serum levels of TNF-α, but had no significant effect on the activity of SOD and the levels of MDA, CRP and IL-1β between experimental and control groups. Dietary Se yeast supplementation had little effect on the PCV2 virus load in the liver, spleen and lung. However, mice in the selenium yeast group showed a significant decrease in microscopic lesion scores in the lung and spleen compared with those in the control group (Pμ0.05). These data indicate Se yeast attenuated the PCV2 infection through altering the systemic inflammation and maintaining the normal organ morphology.

Biochemical Comparison of Commercial Selenium Yeast Preparations

The trace mineral selenium (Se) is an essential element for human and animal nutrition. The addition of Se to the diet through dietary supplements or fortified food/feed is increasingly common owing to the often sub-optimal content of standard diets of many countries. Se supplements commercially available include the inorganic mineral salts such as sodium selenite or selenate, and organic forms such as Se-enriched yeast. Today, Se yeast is produced by several manufacturers and has become the most widely used source of Se for human supplementation and is also widely employed in animal nutrition where approval in all species has been granted by regulatory bodies such as the European Food Safety Authority (EFSA). Characterisation and comparison of Se-enriched yeast products has traditionally been made by quantifying total selenomethionine (SeMet) content. A disadvantage of this approach, however, is that it does not consider the effects of Se deposition on subsequent digestive availability. In this study, an assessment was made of the water-soluble extracts of commercially available Se-enriched yeast samples for free, peptide-bound and total water-soluble SeMet. Using LC-MS/MS, a total of 62 Se-containing proteins were identified across four Se yeast products, displaying quantitative/qualitative changes in abundance relative to the certified reference material, SELM-1 (P value <0.05; fold change ≥2). Overall, the study indicates that significant differences exist between Se yeast products in terms of SeMet content, Se-containing protein abundance and associated metabolic pathways.

Effects of Selenium Yeast on Oxidative Stress, Growth Inhibition, and Apoptosis in Human Breast Cancer Cells

Recent evidence suggests that selenium (Se) yeast may exhibit potential anti-cancer properties; whereas the precise mechanisms remain unknown. The present study was aimed at evaluating the effects of Se yeast on oxidative stress, growth inhibition, and apoptosis in human breast cancer cells. Treatments of ER-positive MCF-7 and triple-negative MDA-MB-231 cells with Se yeast (100, 750, and 1500 ng Se/mL), methylseleninic acid (MSA, 1500 ng Se/mL), or methylselenocysteine (MSC, 1500 ng Se/mL) at a time course experiment (at 24, 48, 72, and 96 h) were analyzed. Se yeast inhibited the growth of these cancer cells in a dose- and time-dependent manner. Compared with the same level of MSA, cancer cells exposure to Se yeast exhibited a lower growth-inhibitory response. The latter has also lower superoxide production and reduced antioxidant enzyme activities. Furthermore, MSA (1500 ng Se/mL)-exposed non-tumorigenic human mammary epithelial cells (HMEC) have a significant growth inhibitory effect, but not Se yeast and MSC. Compared with MSA, Se yeast resulted in a greater increase in the early apoptosis in MCF-7 cells as well as a lower proportion of early and late apoptosis in MDA-MB-231 cells. In addition, nuclear morphological changes and loss of mitochondrial membrane potential were observed. In conclusion, a dose of 100 to 1500 ng Se/mL of Se yeast can increase oxidative stress, and stimulate growth inhibitory effects and apoptosis induction in breast cancer cell lines, but does not affect non-tumorigenic cells.

Effect of selenium sources on growth performance and tissue selenium retention in yellow broiler chicks

An experiment was conducted to investigate the effects of selenium (Se) sources on growth performance and tissue Se retention in yellow chicks fed a conventional corn-soybean meal basal diet. A total of 2250 one-day-old chicks were fed a Se-unsupplemented corn-soybean meal basal diet (containing 0.10 mg of Se/kg) for six days, and then chicks were assigned by body weight to 1 of 5 treatments with 6 replicates of 75 birds each floor pen in a completely randomized design. Broilers were fed the basal diet (control) or basal diet supplemented with 0.3 mg/kg of Se from sodium selenite, Nano elemental Se, Se yeast A or B for 10 days. The results showed that Se sources did not significantly (P > 0.52) affect growth performance. Se sources significantly affected (P < 0.05) Se concentrations in liver and breast muscle, in which chicks fed the diet supplemented with Se yeast B had higher (P < 0.05) tissue Se concentrations than those fed the diet supplemented with sodium selenite or Nano elemental Se. No differences (P > 0.66) were observed in liver and breast muscle Se concentrations among sodium selenite, Nano elemental Se and Se yeast A. Therefore, the new procedure used in this experiment could detect the differences of the effectiveness among Se sources, and Se yeast B was the most effective Se source for yellow broiler chicks.

Effect of dietary organic selenium on milk selenium concentration and antioxidant and immune status in midlactation dairy cows

This study aimed to investigate the effects of the dietary selenium (Se) source on milk yield, milk Se concentration and antioxidant and immune status in dairy cows. Fourteen multiparous Holstein cows with similar dry matter intake (DMI), milk yield and parity were randomly divided into two groups with seven replicates in each group. The cows in both groups were fed basal diets supplemented with 0.3mg Se/kg DM from sodium selenite or Se yeast, and the background Se level of the basal diet was 0.02mg/kg DM. The experimental period lasted for 60 days. The results indicated that the DMI, milk yield and composition were not affected by the dietary Se source (P>0.10). During the entire experimental period, Se yeast supplementation significantly increased the serum glutathione peroxidase activity and decreased the malondialdehyde content (P=0.00) compared with selenite. The serum selenoprotein P content (30d), thioredoxin reductase and catalase activities (60d), and total antioxidant capacity (60d) were also higher (P<0.05) with Se yeast supplementation than with selenite. Compared with selenite, organic Se supplementation increased the values of immunoglobulin (Ig) A and soluble CD4/soluble CD8 on day 30, soluble CD4 on day 60, and interleukin (IL)-1 during the trial (P<0.05). However, other measures of immunity, such as IgM, IgG, soluble CD8, IL-2, IL-4, IL-6 and tumour necrosis factor, were not affected by the dietary Se source (p>0.10). The total Se in the whole blood and milk were higher with Se yeast supplementation than selenite (P<0.05), and the milk Se concentration was increased markedly over the duration of Se supplementation from day 30 to 60. These results suggested that Se yeast may be more effective than sodium selenite in improving the antioxidant status and increasing the whole blood and milk Se concentrations of dairy cows.

GROWTH PERFORMANCE AND MINERAL STATUS ON GOATS (Capra hircus Linn.) SUPPLEMENTED WITH ZINC PROTEINATE AND SELENIUM YEAST

Twenty two (22) doelings weighing 7.86 ± 2.12 kg were grouped into 6 weight classes in a feeding trial to determine the effects of dietary zinc proteinate and selenium yeast on mineral status and growth performance. The Zn-supplemented groups received 200 mg additional Zn daily from chelated Zn proteinate, an insoluble powder containing 15% elemental Zn. Se-supplemented groups received 3 mg Se from Se yeast consisting mainly of selenomethionine (63%). The four (4) dietary treatments were as follows: T1 : 0 mg Zn + 0 mg Se; T2: 0 mg Zn + 3 mg Se; T3 : 200 mg Zn + 0 mg Se. T4: 200 mg Zn/head + 3 mg Se/head. The experiment was conducted in a 2 x 2 factorial design in RCBD. Napier grass used in the trial contained 89.03 ppm Zn, while the mixture of corn-soybean oil meal had Zn content 49.73 ppm. Supplementation of Zn and Se in the diets composed of 60% Napier and 40% soya-corn mix had no effect on dry matter intake, body weight gain, and feed efficiency. Giving 200 mg Zn/head tends to increase (P<0.05) the Zn concentration in the blood of doelings among the levels of Se. Percent digestibility of Zn decreased with Zn supplementation at 200 mg. Percent apparent digestibility of Zn tends to be higher in animals without mineral supplementation. Results indicate that Zn and Se supplementation did not affect growth performance. Zn supplementation increased blood Zn concentration, but did not affect digestibility of Zn.

Effect of selenium yeast supplementation on naturally acquired parasitic infection in ewes.

Gastrointestinal parasites cause substantial economic losses in pasture-based sheep production systems. Supranutritional organic selenium (Se) supplementation may be beneficial because it improves immune responses to pathogens. To evaluate the effect of Se-yeast supplementation on gastrointestinal parasite load, 30 ewes per treatment group were drenched weekly with no Se, 4.9mg Se/week as Se yeast (maximum FDA-allowed concentration), or supranutritional concentrations of Se yeast (14.7 and 24.5mg Se/week) starting early fall for 85weeks. Fecal samples were collected at weeks 63, 66, 78, and 84 and counted for total trichostrongyle-type eggs and Haemonchus contortus eggs (in samples with ≥200 trichostrongyle eggs/g feces). During breeding season (fall), ewes were kept on pasture; ewes receiving 24.5mg Se/week had lower fecal trichostrongyle egg counts (93 ± 40 eggs/g feces) compared with ewes receiving no Se (537 ± 257 eggs/g feces; P = 0.007) or ewes receiving 4.9mg Se/week as Se yeast (398 ± 208 eggs/g feces; P = 0.03). In winter, fecal trichostrongyle egg counts decreased, and group differences were not apparent. During lambing season (spring), ewes were kept in the barn and fecal trichostrongyle egg counts increased, although no group differences were observed. However, none of the ewes receiving supranutritional Se yeast, and with trichostrongyle egg counts ≥200 eggs/g of feces, but four of the ewes receiving lower Se dosages had H. contortus egg counts ≥1,000 eggs/g feces (P = 0.04). Our results suggest that supranutritional Se-yeast supplementation may enhance resistance to naturally occurring H. contortus gastrointestinal parasitism in sheep.

Dietary antioxidant supplementation enhances lipid and protein oxidative stability of chicken broiler meat through promotion of antioxidant enzyme activity

Recent nutrigenomic studies have shown that animal nutrition can have a major influence on tissue gene expression. Dietary antioxidant supplements can enhance the quality of meat through modification of tissue metabolic processes. This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler breast meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin packaging systems during retail display at 2 to 4°C for up to 21 d. Broilers were fed either a diet with a low-oxidized (peroxide value 23 mEq of O2/kg) or high-oxidized (peroxide value 121 mEq of O2/kg) oil, supplemented with or without an algae-based Se yeast and organic mineral antioxidant pack for 42 d. Lipid and protein oxidation and tissue enzymatic activity were analyzed. In all packaging systems, lipid oxidation (TBA reactive substances) was inhibited by up to 32.5% (P < 0.05) with an antioxidant-supplemented diet when compared with diets without antioxidants, particularly in the HiOx and PVC systems. Protein sulfhydryls were significantly protected by antioxidant diets (e.g., by 14.6 and 17.8% for low-and high-oxidized dietary groups, respectively, in PVC d 7 samples). Glutathione peroxidase, catalase, and superoxide dismutase activities were significantly higher (P < 0.05) in antioxidant-supplemented diets compared with the basal diet, regardless of oil quality. Also, serum carbonyls were lower in broilers fed a low-oxidized antioxidant-supplemented treatment. The results demonstrate that dietary antioxidants can minimize the oxidative instability of proteins and lipids, and the protection may be linked to improved cellular antioxidant enzymatic activity.

Organic selenium increases PHGPx, but does not affect quality sperm in raw boar semen

This study assessed the effects of feeding organic selenium (Se) on sperm morphology, motility, membrane integrity and lipidic peroxidation, also on sperm ATP and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in raw semen of mature boars. Twelve boars were divided into three groups: Control, 0.3ppm sodium selenite, Inorganic, 0.5ppm sodium selenite and Organic, 0.5ppm Se yeast for 11 weeks. Organic diet presented a higher total sperm number (P<0.05) when compared to the inorganic treatment; however, no difference was observed regarding volume, sperm concentration, number of cells with plasma and/or acrosomal membrane integrity, membrane mitochondrial potential, ATP assay and Se concentration in seminal and blood content. Also, no difference was observed on motility parameters, sperm morphology and membrane peroxidation, however, PHGPx was influenced (P<0.05) in organic treatment. Thus organic Se feeding influenced none of the analyzed seminal characteristics in raw semen, except for PHGPx and total number of sperm.

Baseline Selenium and Prostate Cancer Risk: Comments and Open Questions

Baseline Selenium and Prostate Cancer Risk: Comments and Open Questions

Organic selenium supplementation increases PHGPx but does not improve viability in chilled boar semen

This study evaluated the effects of dietary organic selenium (Se) on viability of chilled boar semen. Twelve boars were divided into three groups: control (CON), 0.3 mg kg(-1) sodium selenite; inorganic (INO), 0.5 mg kg(-1) sodium selenite and organic (ORG), 0.5 mg kg(-1) Se yeast. The experiment was conducted within 10 weeks, and analysis was performed fortnightly, in storage semen by 72 h. No effect was observed on motility; however, straightness and linearity percentages were higher (P < 0.05) in the animals receiving CON diet compared with INO group. Percentages of cells with both plasma and acrosomal intact membranes, lipidic membrane peroxidation and mitochondrial membrane potential were similar on all treatments. Animals receiving CON diet presented higher (P < 0.05) values of ATP when compared with INO group. The PHGPx was higher (P < 0.05) in animals that received ORG in comparison with INO group. In conclusion, organic selenium supplementation increases PHGPx but does not improve chilled semen viability in 72 h.

Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact1

The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated mineral sources, organic Se yeast, DFM, and Yucca schidigera extract did not decrease most nutrient concentrations excreted. Horses consuming organic selenium as part of the additive diet had lower fecal and urine Se concentrations, as well as greater fecal K concentrations.

Influence of Different Amounts and Sources of Selenium Supplementation on Performance, Some Blood Parameters, and Nutrient Digestibility in Lambs

Two trials were conducted in a 2 × 2 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different sources of selenium (Se) on performance, blood metabolites, and nutrient digestibility in male lambs on a barley-based diet. The first trial lasted for 70 days and consisted of 30 lambs (35.6 ± 2.6 kg mean body weight, about 4-5 months of age) which were randomly allotted to five treatments including: (1) basal diet (containing 0.06 mg Se/kg DM; control) without supplementary Se, (2) basal diet + 0.20 mg/kg Se as sodium selenite (SeS 0.20), (3) basal diet + 0.40 mg/kg Se as sodium selenite (SeS 0.40), (4) basal diet + 0.20 mg/kg Se as selenium yeast (SeY 0.20), and (5) basal diet + 0.40 mg/kg Se as selenium yeast (SeY 0.40). For the second trial, four lambs from each group of experiment 1 were randomly allocated to individual metabolic cages for 14 days to measure the effects of dietary Se on nutrient digestibility. The results revealed that there were no significant differences for average daily gain, average daily feed intake, feed/gain ratio, hematological parameters (packed cell volume, red blood cell, white blood cell, and hemoglobin values), serum total protein, albumin, globulin, aspartate amino transferase, alkaline phosphatase, and creatine phosphokinase due to supplementation of different amounts and sources of Se in lambs. Dietary Se supplementation significantly improved (P < 0.001) glutathione peroxidase activity in blood. Furthermore, at the end of the trial, serum tri-iodothyronine (T3) amount also increased (P < 0.05), while serum thyroxine (T4) amount decreased (P < 0.05). Digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber increased (P < 0.05) by Se yeast supplementation. It may be concluded that supplementation of Se in lambs had no significant effect on performance and blood hematology, but increased blood glutathione peroxidase activity and serum T3 amount and decreased serum T4 amount as compared to non-supplemented control lambs. Furthermore, Se yeast improved nutrient digestibility in lambs.

Comparative study of a new organic selenium source v. seleno-yeast and mineral selenium sources on muscle selenium enrichment and selenium digestibility in broiler chickens

Two experiments were conducted on broiler chickens to compare the effect of a new organic Se source, 2-hydroxy-4-methylselenobutanoic acid (HMSeBA; SO), with two practical Se additives, sodium selenite (SS) and Se yeast (SY). The relative bioavailability of the different Se sources was compared on muscle (pectoralis major) total Se, selenomethionine (SeMet) and selenocysteine (SeCys) concentrations and apparent digestibility of total Se (ADSe). In the first experiment, from day (d) 0 to d21, Se sources were tested at different supplied levels and compared with an unsupplemented diet (NC). No significant effects were observed on growth performance during the experimental period. However, the different Se sources and levels improved muscle Se concentration compared with the NC, with a significant source effect in the following order: SS < SY < SO (P<0·05). Seleno-amino acids speciation results for NC, SY and SO at 0·3 mg Se/kg feed indicated that muscle Se was only present as SeMet or SeCys, showing a full conversion of Se by the bird. The second experiment (d0-d24) compared SS, SY or SO at 0·3 mg Se/kg feed. The ADSe measurements carried out between d20 and d23 were 24, 46 and 49% for SS, SY and SO, respectively, with significant differences between the organic and mineral Se sources (P<0·05). These results confirmed the higher bioavailability of organic Se sources compared with the mineral source and demonstrated a significantly better efficiency of HMSeBA compared with SY for muscle Se enrichment.

Colostrum and milk selenium, antioxidative capacity and immune status of dairy cows fed sodium selenite or selenium yeast

Dietary selenium (Se) can be supplemented from organic or inorganic sources and this may affect Se metabolism and functional outcome such as antioxidative status and immune functions in dairy cows. A feeding trial was performed with 16 Holstein-Friesian dairy cows fed with a total mixed ration (0.18 mg Se/kg dry matter (DM)) either without Se supplement (Control, n = 5), or with Se from sodium selenite (Group SeS, n = 5) or Se yeast (Group SeY, n = 6). In Groups SeS and SeY, the Se supplementation amounted to an additional intake of 4 mg Se and 6 mg Se/d during gestation and lactation, respectively. The effect of both Se sources was characterised by milk Se and antioxidant levels, and the phenotyping and functional assessment of phagocytic activity of milk immune cells. Se yeast has been found to increase (p ≤ 0.001) the milk Se and antioxidant levels markedly compared to the control group. The experimental treatment did not affect the immune parameters of the cows. Lymphocyte subpopulations and phagocytosis activity of neutrophilic granulocytes were affected neither by the Se intake nor by the two different dietary supplements. It can be concluded that sodium selenite and Se yeast differ considerably in their effects on antioxidant status in dairy cows. However, the basal dietary Se concentration of 0.18 mg/kg DM seemed to be high enough for the measured immune variables.

Microencapsulated sodium selenite supplementation in dairy cows: effects on selenium status

The objective of this study was to compare the efficiency of transfer of selenium (Se) to plasma and milk from inorganic sodium selenite, either free or microencapsulated, and from selenized yeast in dairy cows. The study consisted of an in situ-nylon bags incubation, and in an in vivo experiment to compare the Se status of cows supplemented with either sodium selenite, microencapsulated sodium selenite, or Se yeast. Thirty dairy cows, divided in five groups, were fed the following diets: the control group (CTR) received a total mixed ration supplemented with sodium selenite in order to have 0.3 mg/kg DM of total Se; 0.3M and 0.5M groups received the same control diet supplemented with lipid microencapsulated sodium selenite to provide 0.3 and 0.5 mg/kg DM of total Se, respectively; 0.3Y and 0.5Y groups received selenized yeast to provide 0.3 and 0.5 mg/kg of total Se, respectively. Cows were fed the supplements for 56 days during which milk, blood, and fecal samples were collected weekly to conduct analysis of Se and glutathione peroxidase (GSH-px) activity. Se concentration in the nylon bags was assessed to 72%, 64%, and 40% of the initial value (time 0) after 4, 8, and 24 h of incubation, respectively. In vivo, cows supplemented with 0.3 mg/kg of microencapsulated Se had higher milk Se concentration compared to CTR. The increment was more pronounced at the highest inclusion rate (0.5 mg/kg, 0.5M group). GSH-px activity was not significantly affected by treatments. The results indicate that lipid microencapsulation has the potential to protect nutrients from complete rumen reduction and that Se from microencapsulated selenite is incorporated in milk more efficiently than the free form. Microencapsulated sodium selenite was shown to be comparable to Se-yeast in terms of availability and incorporation in milk when fed at 0.3 mg/kg DM, whereas the inclusion in the diet at 0.5 mg/kg DM resulted in higher plasma and milk concentrations than selenized yeast.

Effects of Selenium Source and Level on Growth Performance, Tissue Selenium Concentrations, Antioxidation, and Immune Functions of Heat-Stressed Broilers

An experiment is conducted to investigate the effects of selenium (Se) source and level on growth performance, tissue Se concentrations, antioxidation, and immune functions of heat-stressed broilers from 22 to 42 days of age. A total of 210 22-day-old Arbor Acres commercial male chicks were assigned by body weight to one of seven treatments with six replicates of five birds each in a completely randomized design involving a 3 × 2 factorial arrangement plus one Se-unsupplemented basal diet control (containing 0.027 mg of Se/kg). The three Se sources were sodium selenite (Na₂SeO₃), Se yeast, and AMMS Se (Se protein), and the two supplemental Se levels were 0.15 or 0.30 mg Se/kg. All birds were reared under heat-stressed condition (33 ± 1 °C during 0900-1700 hours and 27 ± 1 °C during 1900-0700 hours with a relative humidity of 60-80 %). The results showed that heat-stressed chicks fed Se-supplemented diets had higher (P < 0.10) average daily feed intake, Se concentrations in liver and breast muscle, liver glutathione peroxidase (GSH-Px) activity, serum antibody titers against H5N1(Re-4 strain), H5N1(Re-5 strain) and lower (P < 0.01) mortality compared with the control. Chicks fed the diets supplemented with 0.30 mg/kg of Se had higher (P < 0.05) Se concentrations in liver and breast muscle, liver GSH-Px activity, and serum antibody titer against H5N1 (Re-4 strain) than those fed the diets supplemented with 0.15 mg/kg of Se. Broilers fed the diets supplemented with Se yeast had higher (P < 0.001) Se concentrations in liver and breast muscle than those fed the diets supplemented with Na₂SeO₃ or AMMS Se. However, broilers fed the diets supplemented with AMMS Se had higher (P < 0.05) serum antibody titers against H5N1 (Re-4 strain) and H5N1 (Re-5 strain) than those fed the diets supplemented with Na₂SeO₃. These results indicated that Se yeast was more effective than Na₂SeO₃ or AMMS Se in increasing tissue Se retention; however, AMMS Se was more effective than Na₂SeO₃ or Se yeast in improving immune functions of heat-stressed broilers.

The effect of various forms of selenium supplied to pregnant goats on selected blood parameters and on the concentration of Se in urine and blood of kids at the time of weaning

&amp;nbsp; 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&amp;nbsp;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 &amp;lt; 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&amp;nbsp;&amp;plusmn; 20.3 &amp;mu;g/l; Se-I: 156.3 &amp;plusmn; 34.3 &amp;mu;g/l; Se-P: 152.6 &amp;plusmn; 41.5 &amp;mu;g/l; Se-L: 146.7 &amp;plusmn; 20 0 &amp;mu;g/l; C: 67.6 &amp;plusmn; 13.1 &amp;mu;g/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 &amp;plusmn; 12.8 nmol/l; Se-I: 66.5 &amp;plusmn; 13.2 nmol/l; Se-P: 76.2 &amp;plusmn; 25.7 nmol/l; Se-L: 84.5 &amp;plusmn; 14.8 nmol/l; C: 92.7 &amp;plusmn; 13.4 nmol/l). Significant differences were found between the group C and groups Se-I and Se-P (P &amp;lt; 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 effect of dietary selenium intake on numbers of T and B cells in C57BL/6 mice with chronic inflammation

Selenium (Se) as a nutrient has many beneficial functions related to its nutritional, biochemical and molecular properties. Se is important for adequate immune response. In this study dams were fed a Torula yeast Se depletion diet for the final week of gestation and through lactation. At 23 days, 47 pups were weaned to the depletion diet or to diets with 0.2, 2 or 4 mg/kg diet Se added as sodium selenate for 14 weeks. Four weeks before necropsy lipopolysaccharide (LPS) time‐release pellets (0 or 0.1μg/g body weight/d) pellets were implanted subcutaneously. At necropsy the bone marrow from femur was flushed with saline, labeled with fluorochrome conjugated primary antibodies (CD3, B220, and CD4) and analyzed by flow cytometry (FACS). LPS stimulation versus placebo increased numbers of T helper cells (1.7×106 vs 0.93×106), T cells (0.57×106 vs 0.31×106) and B cells (3.3×106 vs 2.5×106). In addition CD3+ cell numbers were greater with increasing Se intake (p&lt;0.03). Although the immune system is dependent upon production of oxidative molecules as a protection against microbial pathogens, benefits of Se also include protection from excessive damage by oxidative radicals. Further understanding of the mechanisms by which dietary Se affects these immune cell populations will contribute to knowledge of using Se supplementation to affect T cell mediated immune response. (Supported by Oklahoma Center for Advancement of Science &amp; Technology)

The Effects of Selenium Source on Measures of Selenium Status of Mares and Selenium Status and Immune Function of Their Foals

The effect of organic and inorganic sources of selenium (Se) on measures of Se status of mares and their foals, Se concentrations of colostrum and milk, and indices of immune function of foals was studied. Twenty late-gestation Standardbred mares were randomly assigned to one of two groups. All mares received an identical balanced ration, except for the source of supplementary Se: one group received organic Se (Se yeast) and the other group received inorganic Se (sodium selenite), fed to deliver 0.3 mg/kg supplementary Se based on total ration dry matter. Mares received the experimental diet from 2 months before estimated due date until 1 month after foaling. Source of Se did not affect Se concentrations in maternal plasma, red blood cells, colostrum, or milk. At 1 month of age, foals from mares fed organic Se had higher red blood cell Se concentration than foals from mares fed inorganic Se (P < .05). Measures of immunity included serum immunoglobulin G concentration, lymphocyte proliferation in response to concanavalin A, and relative cytokine gene expression of stimulated lymphocytes (interferon gamma [IFNγ], interleukin [IL]-2, IL-5, IL-10, tumor necrosis factor alpha [TNFα]) and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Relative gene expression of IL-2, TNFα, and IFNγ by foal lymphocytes was associated with the source of Se supplementation provided to the mares. We conclude that the source of dietary Se provided to mares may influence the immune function of foals at 1 month of age through changes in relative gene expression of certain lymphocyte cytokines.