Ppm Se Research Articles

PSXIII-8 Determining the effects of selenium content of high-selenium forages on weight gain in growing lambs

Abstract High selenium (Se) forages grow on seleniferous soils in many parts of the world and upon Se-contaminated rangelands such as in the Western Phosphate Resource Area in the western United States. When consumed in large enough amounts or for extended durations, animals can be poisoned, developing acute or chronic selenosis. Naïve livestock will indiscriminately consume forage with increased concentrations of Se if available. However, most animals upon ingesting a sublethal Se dose will become averted to Se-rich plants and select forages with decreased Se concentrations. The purpose of this study was to determine Se concentrations in feed that cause reduced feed intake and decreased body weight (BW) gain in growing lambs (6 to 8 mo of age). Lambs (n = 5) were randomly divided into four groups and were fed a control pellet (< 1 ppm Se) at 1.5% of their BW and had free choice to a custom Se alfalfa pellet containing < 1 (control), 10, 20, or 40 ppm Se for 8 wk. During the 8 wk period the lambs gained 32.9 ± 4.1, 27.8 ± 1.8, 18.9 ± 9.2, and 7.4 ± 2.8% (mean ±SD) of their initial BW in the < 1 (control), 10, 20, or 40 ppm Se groups, respectively. After the 8 wk were completed, the lambs were fed only the custom Se alfalfa pellets, with < 1 (control), 10, 20, or 40 ppm Se, free choice for four additional weeks. As Se concentration in the pellets fed increased, the feed intake and BW gains significantly decreased. Lambs in the control and 10 ppm Se groups ate approximately 2-fold more than the lambs in the 40 ppm Se group, which lost over 3% of their initial BW. Understanding the concentration of Se in forages and how it affects appetite and BW gain allows range managers to better manage seleniferous or Se-contaminated ranges to safely use sheep on these types of rangelands. Additional work is needed to better understand the management of other livestock species grazing on high Se-containing ranges and pastures.

Effects of Combined Organic Selenium and Zinc Supplementation on In Vitro Ruminal Enzyme Activities and Relative Populations of Several Bacterial Species

Selenium (Se) and zinc (Zn) are essential animal microminerals. Combining Se and Zn (Se-Zn) as a feed additive in its influence on rumen fermentation patterns is still very limited, so further investigation is needed. The present study explored the supplementation impact of combined Se-Zn from organic sources on rumen enzyme activity and relative abundance of several bacterial species through an in vitro method. Five treatments, each with six replicates were used in the study. The first group treated without Se and Zn supplementation (T0, control), the second group treated with 0.3 ppm Se + 60 ppm Zn (T1), the third group treated with 0.45 ppm Se + 60 ppm Zn (T2), the fourth group treated with 0.3 ppm Se + 90 ppm Zn (T3), and the fifth group treated with 0.45 ppm Se + 90 ppm Zn (T4). The parameters observed included rumen microbial enzyme activities (carboxyl methyl cellulase, amylase, protease) and the relative abundance of rumen microbes (Ruminococcus sp., Ruminococcus flavefaciens, Ruminococcus albus, Streptococcus sp., Prevotella ruminicola, and Eubacterium ruminantium). Results indicated that carboxyl methyl cellulase (CMC-ase) and amylase activities raised in T2, T3, and T4 in comparison to T1 and T0 treatments. Protease activity and protein enzyme content increased in T2 compared to all treatments. The relative abundance of Ruminococcus sp. and Ruminococcus albus was higher in T2 and T3 compared to T0 treatment. Furthermore, an elevated Ruminococcus flavefaciens was indicated in T2 compared to other treatments. The T2, T3, and T4 led to higher abundances of Eubacterium ruminantium, Prevotella ruminicola, and Ruminococcus albus compared to T0 and T1. It is concluded that organic Se and Zn enhanced the relative abundance of several bacterial species and the activity of enzymes in the rumen; optimal results are recommended when combining 0.45 ppm Se + 60 ppm Zn.

Selenium deficiency induces irritable bowel syndrome: Analysis of UK Biobank data and experimental studies in mice

Irritable bowel syndrome (IBS) patients exhibit significantly lower levels of serum selenium (Se) compared to healthy controls. This study integrates a prospective cohort analysis and animal experiments to investigate Se deficiency as a potential risk factor for IBS. Using data from the UK Biobank, a longitudinal analysis was conducted to explore the associations between dietary Se intake and the risk of incident IBS. In animal study, C57BL/6 mice were fed diets with normal (0.2 ppm) or low (0.02 ppm) Se levels to assess the impacts of Se deficiency on IBS symptoms. Furthermore, we performed 16 S rRNA sequencing, untargeted colonic fecal metabolomics analysis, and colon transcriptome profiling to uncover the regulatory mechanisms underlying Se deficiency-induced IBS. The analysis of UK Biobank data revealed a significant correlation between low dietary Se levels and an increased incidence of IBS. In the experimental study, a low Se diet induced IBS symptoms, evidenced by elevated abdominal withdrawal reflex scores, colon inflammation, and severe pathological damage to the colon. Additionally, the low Se diet caused disturbances in gut microbiota, characterized by an increase in Faecalibaculum and Helicobacter, and a decrease in Bifidobacterium and Akkermansia. Combined colonic fecal metabolomics and colon transcriptome analysis indicated that Se deficiency might trigger IBS through disruptions in pathways related to "bile excretion", "steroid hormone biosynthesis", "arachidonic acid metabolism", and "drug metabolism-cytochrome P450". These findings underscore the significant adverse effects of Se deficiency on IBS and suggest that Se supplementation should be considered for IBS patients.

Transcriptomic Changes in Response to Form of Selenium on the Interferon-Tau Signaling Mechanism in the Caruncular Tissue of Beef Heifers at Maternal Recognition of Pregnancy.

We have reported that selenium (Se) provided to grazing beef cattle in an inorganic (ISe) form versus a 1:1 mixture (MIX) of inorganic and organic (OSe) forms affects cholesterol biosynthesis in the corpus luteum (CL), the abundance of interferon tau (IFNτ) and progesterone (P4)-induced mRNAs in the caruncular (CAR) tissue of the endometrium, and conceptus length at maternal recognition of pregnancy (MRP). In this study, beef heifers were supplemented with a vitamin-mineral mix containing 35 ppm Se as ISe or MIX to achieve a Se-adequate status. Inseminated heifers were killed at MRP (d 17, n = 6 per treatment) for tissue collection. In CAR samples from MIX versus ISe heifers, qPCR revealed that mRNA encoding the thyroid regulating DIO2 and DIO3 was decreased (p < 0.05) and a complete transcriptomic analysis revealed effects on the interferon JAK-STAT1/2 pathway, including decreased expression of mRNAs encoding the classical interferon stimulated genes IFIT1, IFIT2, IFIT3, IRF1, IRF9, ISG15, OAS2, and RSAD2 (p < 0.05). Treatment also affected the abundance of mRNAs contributing to the immunotolerant environment (p < 0.05). In combination, these findings suggest more advanced preparation of the CAR and developing conceptus for implantation and to evade immune rejection by the maternal system in MIX- vs. ISe-treated heifers.

112 Effect of Selenium Sources on Sow Productive and Reproductive Performance and Their Progeny

Abstract Dietary selenium (Se) supplementation is a standard practice, using either an inorganic form, such as sodium selenite (SS) or organic forms, like SeYeasts (SY) or pure forms of selenomethionine (SeMet). Hydroxy-selenomethionine (OH-SeMet) is a chemically synthesized organic Se form and has been proven to be efficient in transferring Se from the diet to muscle compared with SS or SY products. The transfer of Se in tissues, in fact, leads to the buildup of a Se reserve as SeMet in the body that participates in maintaining effective antioxidant defenses and supports animal performance, particularly under challenging conditions. This trial aimed to determine the effects of different Se sources on the productive and reproductive performance of sows and on their progeny. Sows (n = 120) were allocated in individual cages in one of the three treatments according to the number of parities, number of piglets in previous parturition, body condition score and initial body weight. The experiment lasted 141 days (from the insemination of sows up to the weaning of the piglets at 21 days). A corn-soybean-based basal diet was formulated to meet the nutrient requirements of the sows during gestation and lactation. The Se supplementation was 0.35 ppm of Se either from SS, SY or OH-SeMet. The number of total piglets born showed a tendency (P = 0.06) for treatments fed organic Se sources (15.6 OH-SeMet; 15.4 SY vs 14 SS) with no differences on the litter weight at birth. However, sows fed OH-SeMet weaned more piglets (13.4) than the other treatments (12.5 SY and 12.2 SS, respectively, P &amp;lt; 0.01). The litter weight at weaning showed no differences among treatments (73.4, 70.4 and 75.9kg for SS, SY and OH-SeMet, respectively). The feed conversion of the sows during lactation was also affected by the Se source, in which OH-SeMet showed a significantly reduced FCR of 2.6 vs 3.0 and 3.1 for SS and SY, respectively (P &amp;lt; 0.01). Piglets fed organic sources showed a decreased diarrhea incidence (scores 2 and 3) compared with SS (P &amp;lt; 0.001), respectively, 5.68 vs 3.28 and 3.27%. The Se concentration of sows’ colostrum and milk of sows were numerically improved from SS to SY, but only significantly greater on OH-SeMet treatment. The same pattern of Se concentration in the milk was observed in the serum of piglets 48 h after birth (142, 122 and 228 μg/kg for SS, SY and OH-SeMet, respectively) and at weaning (85, 85 and 117 μg/kg for SS, SY and OH-SeMet, respectively). Feeding pure forms of organic Se, such as OH-SeMet supports the productive and reproductive performance of sows and improve the Se status of the progeny. Organic Se also reduces the diarrhea of piglets, compared with SS.

Influence of Select Dietary Trace Minerals and their Levels on Growth Performance, Nutrient Utilization and Minerals Balance in Male Goats.

A study was conducted on eighteen male goats to evaluate the effect of incremental levels of select dietary trace minerals on growth performance, nutrient utilization and minerals balance. Animals (16.65 ± 0.53kg average BW) were randomly divided into three groups and fed a basal diet to meet the requirement of all the nutrients except select trace minerals for 60 days. Groups were T1 (0.204 ppm Se, 35.29 ppm Zn, 7.37 ppm Cu, 39.79 ppm Mn), T2 (0.504 ppm Se, 55.29 ppm Zn, 17.37 ppm Cu, 59.79 ppm Mn), and T3 (0.804 ppm Se, 75.29 ppm Zn, 27.37 ppm Cu, 79.79 ppm Mn). Daily dry matter intake (DMI) (% BW) was lower (P < 0.05) in T3 as compared to other groups however, average daily gain (ADG) in body weight (P = 0.113) and feed: gain ratio (P = 0.102) showed subtle improvement in T2 and T3 groups. Feeding of higher levels of select trace minerals did not affect the intake and digestibility of nutrients, or plane of nutrition, however, the digestibility of non-fiber carbohydrates (NFC) increased (P = 0.004) in T2 and T3 groups than T1. The balance of N, Ca, P and Cu did not differ among the groups but balance of Zn, Mn and Se increased in T2 and T3 groups than T1 group. It is concluded that feeding higher levels of Zn (75.29 ppm), Cu (27.37 ppm), Mn (79.79 ppm) and Se (0.804 ppm) in combination, improved NFC digestibility, retention of Zn, Mn and Se and had subtle beneficial effects on the growth performance of male goats.

Genotypic and environmental effects on quality and nutritional attributes of Moroccan barley cultivars and elite breeding lines.

Although barley is mainly used for livestock feed and beverages, its use as human feed can enrich human diets with some health benefits. The development of new hulless varieties rich in β-glucans and micronutrients can enhance the use of barley as food, but little is known about the effects of the environment on these nutritional traits. In this study, we evaluated five Moroccan varieties and two elite breeding lines of barley at four locations in Morocco during the 2016-2017 and 2017-2018 cropping seasons. The results showed highly significant differences between genotypes for β-glucan, protein, iron, and selenium contents, as well as 1000 kernel weight, but not zinc content; significant to highly significant differences between environments for all traits except β-glucan content; and significant to highly significant interactions for all traits. The highest level of β-glucan content has reached 11.57% observed at the Sidi El Aydi site during the growing season 2017-2018 for the hulless variety Chifaa. This variety has shown the highest content of β-glucan (6.2-11.57%) over all environments except at Tassaout during the 2016-2017 seasons. The breeding line M9V5 has achieved significantly higher protein content at all the locations during the two growing seasons, ranging from 12.38 to 20.14%. Most hulless lines had significantly higher β-glucan and protein contents, but lower 1000 kernel weight. For micronutrients, the content ranges were 28.94 to 38.23 ppm for Fe, 28.78 to 36.49 ppm for Zn, and 0.14 to 0.18 ppm for Se, with the highest content for Fe and Zn shown by the breeding line M9V5 and Chifaa showing average contents of 33.39 ppm, 35.34 ppm, and 0.18 ppm for Fe, Zn, and Se, respectively. The GGE biplot confirmed the high and relatively stable content of β-glucan and acceptable micronutrient contents of the Chifaa variety and identified Marchouch as the most discriminant site to breed for biofortified barley varieties.

Bionanotechnology of Selenite Ions Recovery into Nanoselenium by Probiotic Strains of Lactobacteria and Tolerance of Lactobacteria to Sodium Selenite

Green synthesis of nanoparticles (NPs) using living cells is a promising and new tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs, but biological methods are preferred because of their environmentally friendly, clean, safe, cost-effective, simple, and efficient sources for high productivity and purity. Aim. To investigate the processes of bioreduction of selenite ions into nanoselenium by probiotic strains of lactobacilli Lactobacillus plantarum IMV B-7679 and L. casei IMV B-7280. Methods. Cultivation of lactobacilli L. plantarum IMV B-7679 and L. casei IMV B-7280 was carried out in vials (500 cm3) on a rotary shaker (220 rpm) at 30 °C for 2 days on the Man, Rogosa, and Sharpe (MRS) broth nutrient medium. Sodium selenite was additionally added to the environment in different concentrations from 1 to 30 ppm by Se. The number of viable bacterial cells in 1 mL of suspension was determined by the method of limiting dilutions in the case of sowing aliquots on a nutrient medium containing 0.2% agar-agar. Cultures of L. plantarum IMV B-7679 or L. casei IMV B-7280 were grown in the liquid MRS broth medium with low pH in the presence or absence of Na2SeO3. The concentration of sodium selenite ranged from 1 to 30 ppm by Se level. The number of microorganisms was determined by inoculation (0.1 mL of suspension) in dense media on cups with MRS agar medium, and the seeding dose was 107 cells/Petri dish. The tolerance of lactobacilli to the selenite ions was evaluated by the decrease in the number of CFU when sowing aliquots taken from culture samples grown in the presence or absence of selenite. The results of the experiments were presented in CFU and transferred to Log CFU/cm3. The characteristics of Nano-Se were studied using transmission electron microscopy (TEM). Results. It was found that after 48 h incubation in an MRS medium with the addition of sodium selenite from 1 to 30 ppm, the culture of L. plantarum IMV В-7679 was the most resistant. Thus, enrichment of the culture medium with 30 ppm of Se in the Na2SeO3 composition led to a decrease in the number of L. plantarum IMV B-7679 to 5.17 ± 0.09 Log CFU/cm3 against 4.41 ± 0.11 Log CFU/cm3 for L. casei IMV B-7280 in the control. The use of lower concentrations (1—3 ppm of Se in Na2SeO3) did not affect the change in morphology and cultural properties of L. plantarum IMV B-7679. The ability of L. casei IMV B-7280 and L. plantarum IMV B-7679 cultures to grow on MRSA nutrient medium in the presence of 3 ppm Se was shown. Higher tolerance to sodium selenite was found for L. plantarum IMV B-7679. Thus, increasing the concentration to 30 ppm of Se in the form of Na2SeO3 led to a decrease in the viability of only the culture of L. casei IMV B-7280. That is, the studied lactobacilli showed different ability to grow in the presence of selenite ions. The formation of round electron-dense granules sizing from 30 nm to 250 nm was observed using TEM. Both probiotic strains showed the ability to restore selenite ions with the accumulation of intracellular Nano-Se and the release of Nano-Se into the culture medium, which was accompanied by color shifts from yellowish to red-brown. The partial destruction of L. casei IMV B-7280 cells under the influence of oxyanions was revealed, which was accompanied by the release of culture-synthesized electron-dense Nano-Se particles. Conclusions. The optimal conditions for the growth of L. plantarum IMV B-7679 and L. casei IMV B-7280 in the presence of Na2SeO3 were established, and it was proved that lactobacilli have different abilities to grow in the presence of selenite ions. The obtained data indicate that the investigated probiotic strains showed the ability to restore selenite ions along with the accumulation of intracellular Nano-Se and the release of Nano-Se into the culture medium.

Trace Element Composition of Pyrite from Selected Black Shale and Chert Exposures in the Central Belt of Peninsular Malaysia: Implications for Mineral Exploration

Sedimentary and hydrothermal pyrites contained in selected Malaysian black shale and cherts have been analysed using laser ablation inductively coupled plasma (LA ICP-MS) and electron probe microanalysis (EPMA) at the University of Tasmania, Australia. This study shows that gold is concentrated in sedimentary and hydrothermal pyrite in the Middle Permian to Late Triassic black shales and Devonian cherts. According to LA ICP-MS analysis, gold contents in pyrite varied from 0.5 to 0.8 ppm Au in the Permo-Triassic black shale and between 0.2 and 0.8 ppm Au in the Devonian cherts. The lowest level of gold (0.3 ppm Au) was observed in the Permo-Triassic black shale that crops out at the Selinsing gold mine. In the Permo-Triassic period, the selenium contents display one peak (average range: 63.4–103.4 ppm Se) that is far from any gold deposit and one lowest point (average: 5.3 ppm Se) at the Selinsing gold deposit. In the Devonian period, the selenium content in sedimentary pyrite shows a peak (72.6–243.8 ppm Se) in the cherts. EPMA and LA ICP-MS data show consistent Se content variation in the Devonian and Permo-Triassic periods. Using selenium as a proxy for atmospheric oxygenation, the lowest level of Se content in the Permo-Triassic period is believed to decrease atmospheric oxygenation, as recorded in sedimentary pyrite found in black shale from the Selinsing gold deposit. The two peaks of selenium contents are interpreted as periods of increased atmospheric oxygenation. From an exploration perspective, the concentration of gold in sedimentary pyrites makes them sources for gold in the central sedimentary basin of Peninsular Malaysia. Therefore, the two maximum levels of Se and gold content during Permo-Triassic and Devonian times correspond to two stratigraphic levels of potential for orogenic gold mineralisation in the district. The EPMA data show significant values of Co over Ni in pyrite from the Gua Musang, Semantan, and Karak formation black shales, indicating a volcanic contribution of Co during the formation of sedimentary pyrite. Based on the current study’s findings, gold exploration should not be restricted to areas in and around the Selinsing gold mine, Buffalo Reef, Penjom mine, Tersang mine, and Bukit Koman mine but can be extended to BRSZ Units 1 and 2, Gua Musang, and Karak formations in the central belt of Peninsular Malaysia.

Comparative Effects of Inorganic and Organic Dietary Sources of Selenium on Selenium Levels and Selenium-Dependent Glutathione Peroxidase Activity in Blood of Young Turkeys

The effect of various dietary sources of Se on Se-dependent glutathione peroxidase (SeGSH-Px) activity in plasma and whole blood was studied in turkeys. Dayold poults were fed low Se diets (supplemented with vitamin E) for 15 to 24 days before being fed experimental diets for 7 to 10 days. Menhaden fish meal (0.1 ppm Se) increased plasma SeGSH-Px activity by 45% of the response to 0.1 ppm Se as Na2SeO3. Poults supplemented with 0, 0.1, 0.2, or 0.4 ppm Se as Na2SeO3, had similar increases in plasma and whole blood Se levels; however, SeGSH-Px activity of plasma (r = 0.96) was better correlated with dietary Se than that of whole blood (r = 0.64). The supplement of 0.4 ppm Se increased the activity of SeGSH-Px almost 20 times in plasma but only 1.6 times in whole blood. The effectiveness of several compounds providing 0.2 ppm Se for increasing plasma SeGSH-Px activity was: Na2SeO4 > Se-dl-cystine > Se-dl-methionine and Se-dl-ethionine. The effect of Na2SeO3 was not significantly different from that of Se-dl-cystine, Se-dl-methionine or Se-dl-ethionine. The ratio of SeGSH-Px activity:Se concentration, indicating the amount of Se associated with enzyme activity, was highest in plasma of poults fed Na2SeO4 andSe-dl-cystine. The data demonstrate differences in the availability of various Se sources for SeGSH-Px activity in poults.selenium glutathione peroxidase turkeys fish meal

Short-term effects of dietary selenium on lactating sows to improve litter performance, milk composition and tissue selenium retention in piglets.

This study was conducted to evaluate the short-term effects of dietary selenium supplementation on lactating sows on the physiological response, litter performance, milk composition, and tissue selenium retention in piglets when selenium was provided by different sources and at different levels in a lactation diet. A total of 48 multiparous sows (Yorkshire×Landrace) with average body weight, backfat thickness, and parity were assigned to one of the four treatments with 12 sows per treatment using a 2×2 factorial arrangement in a completely randomized design. Inorganic or organic Se sources were added to the diet at 0.30 ppm and 0.50 ppm Se. Treatments were as follows: i) IS30, basal diet + inorganic Se 0.30 ppm; ii) IS50, basal diet + inorganic Se 0.50 ppm; iii) OS30, basal diet + organic Se 0.30 ppm; and iv) OS50: basal diet + organic Se 0.50 ppm. At Day 21 of lactation, a high tendency of litter weight (p = 0.08) and litter weight gain (p = 0.09) were observed when sows were fed an organic Se source. The milk Se concentration in the organic Se treatment was higher than that in the inorganic Se treatment at Day 21 of lactation (p<0.05). The serum Se concentrations of sows and piglets at Day 21 of lactation were significantly higher when lactating sows were fed organic Se instead of inorganic Se (p<0.01). During the suckling period, the kidney and muscle Se concentrations of piglets at Day 21 of lactation were significantly higher when the sow dietary Se source was organic (p<0.05). Liver Se concentrations were affected by Se source and level (p<0.05). This also resulted in an interaction response at 21 days of lactation (p<0.05). The supplementation of dietary organic Se in a lactating diet could improve sow feed consumption, piglet performance, milk Se level, and the Se status of sows and piglets.

Role of organic selenium in resisting oxidative stress during tropical summer in broiler chicken

The present study was conducted to investigate the effect of selenium supplementation on the oxidative status of hepatic tissue during heat stress in broilers. The study was conducted in two phases, one during autumn and the other during summer with a total of 300 birds. During the first phase, 60 chicks were divided into six replicates with 10 birds in each and during the second phase, 240 chicks were divided into four groups with six replicates containing 10 birds in each. The experimental rations given to different groups were control (Basal ration), HS I (Basal ration), HS II (Basal ration + 0.3 ppm Se, HS III (Basal ration + 0.6 ppm Se) and HS IV (Basal ration + 0.9 ppm Se). Hepatic tissues collected at 21 and 42d were analyzed for oxidative status. HS-induced oxidative stress was revealed by the significant elevation in lipid hydroperoxides, MDA and protein carbonyl levels which in turn triggered the activities of anti-oxidant enzymes, i.e GPx, GST, SOD and G6PD in the hepatic cytosol. The total antioxidant capacity and glutathione concentration were significantly altered due to HS. Selenium at 0.3 ppm was effective in counteracting the oxidative stress at 21d while 0.6 ppm of Se was more effective at 42d. Se supplementation at 0.6 ppm improved the activities of antioxidant enzymes and G6PD. The total antioxidant capacity and GSH concentrations were better improved with 0.6 ppm of Se compared to other treatments.

Hydroxy-selenomethionine enhances the productivity and egg quality of 50- to 70-week-old semi-heavy laying hens under heat stress

Oxidative stress significantly compromises the production efficiency of laying hens. It has been reported in literature that selenium (Se) in poultry diets has a positive effect on mitigating these effects. This study has been carried out to evaluate the effects of Se supplementation in feeds, from either an inorganic or a hydroxy-selenomethionine (OH-SeMet) source, on the performance and physiological traits of 50- to 70-wk-old Dekalb Brown laying hens under heat stress, and on their egg quality after different storage durations. The treatments consisted in supplementing 0.3 ppm of Se as sodium selenite (SS; 45%-0.7g/ton) or OH-SeMet (2%-15g/ton) in twelve 16-bird replicates. Supplementation with OH-SeMet resulted in a better performance of the laying hens than with SS: -5% feed conversion ratio and +3.6% of egg mass. A reduction in egg quality was observed with prolonged egg storage, which was mitigated with the use of OH-SeMet in laying hen diets. The use of OH-SeMet increased the antioxidant capacity of the birds, which showed higher glutathione peroxidase levels in the blood, kidneys, liver, and intestinal mucosa, in addition to a higher Se content in the eggs and a greater bone resistance. Thus, supplementing feeds with 0.3 ppm of OH-SeMet to 50- to 70-wk-old semi-heavy laying hens enhances their antioxidant capacity and leads to a higher egg quality and productivity than SS supplementation.

Economic By-Products in copper Porphyries: Silver in the Ascutita Cu-Porphyry, Romania

The Ascutita porphyry Cu-Mo prospect is located in the SW Poiana Rusca Mountains, Romania. Current assessment estimates a resource of 110 Mt @ 0.15 % Cu-equivalent. In relatively low-grade deposits such as this, by-products such as Ag (2–3 ppm) are important in determining the economic feasibility of the overall orebody. Assayed Cu and Ag have a clear downhole correlation. In the absence of other silver-bearing minerals, or correlations of Ag with other sulphides (e.g., Pb indicating Ag-bearing galena) this suggests Cu-sulphides are instead the dominant hosts of Ag. Petrography of 21 samples from various drillholes show chalcopyrite is the dominant Cu-sulphide present, spatially associated to two stages of pyrite. LA-ICP-MS analysis determined that both chalcopyrite and Stage 3 pyrite (younger) co-host the Ag. Chalcopyrite hosts Ag mostly in solid solution, whilst pyrite hosts Ag within a variety of complex, sulphosalt micro-inclusions undetectable on an SEM, but apparent on time-resolved LA-ICP-MS spectra. These micro-inclusions lock in Cu and Ag, with a bulk median Ag content of 0.79 ppm. The pyrite also contains mean concentrations of 52 ppm Bi and 46 ppm Se: both typically penalty-incurring elements at smelters. The chalcopyrite has a greater Ag concentration than the pyrite (median = 30.3 ppm with potential for 181 ppm), presumably in solid solution. The lattice-bound Ag partitioned into the chalcopyrite through monovalent, simple substitution of Ag+ for Cu+. Occurrence of Ag in the main Cu-bearing phase at Ascutita raises the possibility of combined recovery, and this study demonstrates the value of trace element analysis in geometallurgical assessments of orebodies.

Influence of form of selenium supplementation and tall fescue endophyte toxicity on growth performance, serum parameters, and tissue masses of grazing beef steers.

To test the hypothesis that average daily gain (ADG) and clinical parameters of steers grazing novel non-toxic (NTE) or toxic KY-31 (TE) endophyte-infected tall fescue would be improved by ad libitum intake of vitamin‐mineral mixes (V-M) that contain 27 ppm Se as a 1:1 blend of SELPLEX:sodium selenite (MIX) vs. sodium selenite (ISe), 32 fescue-naïve beef steers partially depleted of Se were randomly assigned to ad libitum consumption ISe vs. MIX for 35 days and fed enough of a NTE/alfalfa/grain diet to achieve 0.57 kg BW gain/day. Then, within Se-form treatments, two steers were randomly assigned to each of four NTE (ISe = 316 ± 31 kg BW, MIX = 315 ± 22 kg BW) or TE (ISe = 316 ± 37 kg BW, MIX = 314 ± 39 kg BW) paddocks for 84 days and had ad libitum access to their respective V-M. The MIXED procedure of SAS was used to assess effects of day, Se-form (ISe, MIX) and endophyte (NTE, TE) treatments, and their interactions. Whole blood Se decreased (P < 0.01) 31% from days 0 to 84 and was 6.2% greater (P < 0.01) for MIX steers. Serum prolactin decreased (P < 0.01) 18% for NTE and 48% for TE steers from days 0 to 84 and was 17% greater (P = 0.01) for MIX vs. ISe for TE steers. Serum alkaline phosphatase activity decreased (P < 0.02) 27% from days 0 to 84 and was 15% greater (P < 0.02) for MIX steers. Serum urea nitrogen increased (P < 0.02) 8.2% from days 0 to 84 for TE but not NTE steers. Average daily gain was less (P < 0.01) for steers grazing TE (−0.18 kg/day) compared with NTE (0.09 kg/d). Although there was increased serum alkaline phosphatase activity and increased serum prolactin for TE + MIX steers compared with TE + ISe steers, MIX supplementation was unable to increase serum prolactin concentrations or ADG to the same levels as steers grazing NTE. Longer adaptation to MIX supplementation ad libitum may be necessary for maximal Se assimilation to restore serum prolactin levels in steers grazing TE.

Effect of Organic Selenium during HS in Broiler Chicken: The Interplay of HSP-70 and PGC-1α

Background: ROS ( Reactive Oxygen Species) accumulated during heat stress induced oxidative stress is involved in triggering the activation of transcription factor, heat shock factor-1 (HSF-1) which further results in the up regulation of HSP. A cooperation between PGC1α and HSF1 in the induction of HSPs in response to thermal stress was reported in mice. Thus, the present study was conducted to investigate the effect of HS (Heat Stress) on HSP-70 and PGC-1α expression in broilers. Method: The study was conducted in two phases, one during autumn and the other during summer with a total of 300 birds. During the first phase, 60 chicks were divided into six replicates with 10 birds in each and during the second phase, 240 chicks were divided into four groups with six replicates containing 10 birds in each. The experimental rations given to different groups were as control (Basal ration), HS I (Basal ration), HS II (Basal ration+0.3 ppm Se, HS III (Basal ration+0.6 ppm Se) and HS IV (Basal ration+0.9 ppm Se). Hepatic tissues were collected for analysis at 21 d and 42 d. Result: The MDA levels and expression of HSP-70 protein in hepatic tissues were increased due to HS both at 21 and 42 d, while the expression of PGC-1α protein increased at 42 d. Se supplementation at 0.3 ppm was effective in decreasing the concentration of MDA and HSP-70 protein at 21d, whereas 0.6 ppm and 0.9 ppm were effective at 42d. Se supplementation decreased the expression of PGC-1α protein at 42 d during HS.

Pituitary and liver selenoprotein transcriptome profiles of grazing steers and their sensitivity to the form of selenium in vitamin-mineral mixes

Many supplemental Se-dependent metabolic effects are mediated through the function of selenoproteins. The full complement and relative abundance of selenoproteins expressed by highly metabolic cattle tissues have not been characterized in cattle. The complement and number of selenoprotein mRNA transcripts expressed by the pituitary and liver of healthy growing beef steers (n = 7 to 8) was characterized using NanoString methodology (Study 1). Of the 25 known bovine selenoproteins, 24 (all but SELENOH) were expressed by the pituitary and 23 (all but SELENOH and SELENOV) by the liver. Transcript abundance ranged (P ≤ 0.05) over 5 orders of magnitude in the pituitary (&amp;gt; 10,000 for GPX3, &amp;lt; 10 for DIO1 and GPX2) and liver (&amp;gt; 35,000 for SELENOP, &amp;lt; 10 for DIO2). Also unknown is the sensitivity of the selenoprotein transcriptome to the form of supplemental Se. The effect of form of supplemental Se on the relative content of selenoprotein mRNA species in the pituitary and liver of steers grazing a Se-deficient (0.07 ppm Se) tall fescue pasture and consuming 85 g/d of a basal vitamin-mineral mix that contained 35 ppm Se as either ISe (n = 6), organically-bound Se (SELPLEX; OSe, n = 7 to 8), or a 1:1 blend of ISe and OSe (MIX, n = 7 to 8) was determined by RT-PCR after sequence-validating the 25 bovine selenoprotein cDNA products (Study 2). In the pituitary, Se form affected (P &amp;lt; 0.05) the relative content of 9 selenoprotein mRNAs and 2 selenoprotein P receptor mRNAs in a manner consistent with a greater capacity to manage against oxidative damage, maintain cellular redox balance, and have a better control of protein-folding in the pituitaries of OSe and MIX versus ISe steers. In the liver, expression of 5 selenoprotein mRNA was affected (P ≤ 0.05) in a manner consistent with MIX steers having greater redox signaling capacity and capacity to manage oxidative damage than ISe steers. We conclude that inclusion of 3 mg Se/d as OSe or MIX versus ISe, forms of supplemental Se in vitamin-mineral mixes alters the selenoprotein transcriptome in a beneficial manner in both the pituitary and liver of growing steers consuming toxic endophyte-infected tall fescue.

Form of dietary selenium affects mRNA encoding interferon-stimulated and progesterone-induced genes in the bovine endometrium and conceptus length at maternal recognition of pregnancy.

Widespread regions of the southeast United States have soils, and hence forages, deficient in selenium (Se), necessitating Se supplementation to grazing cattle for optimal immune function, growth, and fertility. We have reported that supplementation with an isomolar 1:1 mix (MIX) of inorganic (ISe) and organic (OSe) forms of Se increases early luteal phase (LP) concentrations of progesterone (P4) above that in cows on ISe or OSe alone. Increased early LP P4 advances embryonic development. Our objective was to determine the effects of the form of Se on the development of the bovine conceptus and the endometrium using targeted real-time PCR (qPCR) on day 17 of gestation, the time of maternal recognition of pregnancy (MRP). Angus-cross yearling heifers underwent 45-d Se-depletion then repletion periods, then at least 90 d of supplementation (TRT) with 35 ppm Se per day as either ISe (n = 10) or MIX (n = 10). Heifers were inseminated to a single sire after detected estrus (day 0). On day 17 of gestation, caruncular (CAR) and intercaruncular (ICAR) endometrial samples and the developing conceptus were recovered from pregnant heifers (ISe, n = 6 and MIX, n = 6). qPCR was performed to determine the relative abundance of targeted transcripts in CAR and ICAR samples, with the expression data subjected to one-way ANOVA to determine TRT effects. The effect of TRT on conceptus development was analyzed using a one-tailed Student's t-test. When compared with ISe-treated heifers, MIX heifers had decreased (P < 0.05) abundance of several P4-induced and interferon-stimulated mRNA transcripts, including IFIT3, ISG15, MX1, OAS2, RSAD2, DGAT2, FGF2 in CAR and DKK1 in ICAR samples and tended (P ≤ 0.10) to have decreased mRNA abundance of IRF1, IRF2, FOXL2, and PGR in CAR samples, and HOXA10 and PAQR7 in ICAR samples. In contrast, MIX-supplemented heifers had increased (P < 0.05) mRNA abundance of MSTN in ICAR samples and an increase in conceptus length (ISe: 17.45 ± 3.08 cm vs. MIX: 25.96 ± 3.95 cm; P = 0.05). Notably, myostatin increases glucose secretion into histotroph and contributes to advanced conceptus development. This advancement in conceptus development occurred in the presence of similar concentrations of serum P4 (P = 0.88) and whole blood Se (P = 0.07) at MRP.

Effects of selenium source and level on the physiological response, reproductive performance, serum Se level and milk composition in gestating sows.

This study was conducted to evaluate the effects of selenium (Se) source and level on the physiological response, reproductive performance, serum Se level, and milk composition in gestating sows. A total of 54 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness (BF), and parity were assigned to one of five treatments with 10 or 11 sows per treatment using a 2×2 factorial arrangement with one additional treatment in a completely randomized design. Inorganic or organic Se (IS or OS) sources were added to the diet at 0.30 ppm and 0.50 ppm Se. A non-Se-fortified corn-soybean meal basal diet served as a negative control. Treatments were as follows: i) Control: corn-soybean based diet, ii) IS30: control+inorganic Se 0.30 ppm, iii) IS50: control+inorganic Se 0.50 ppm, iv) OS30: control+ organic Se ppm, and v) OS50: control+organic Se 0.50 ppm. At day 21 of lactation, piglet weight and weight gain in the OS treatments were higher than those in the IS treatments (p<0.05). Meanwhile, adding 0.5 ppm Se also resulted in the same significant differences in piglet BW and weight gain (p<0.05). Colostrum and milk Se concentrations increased (p<0.05) with Se level for both Se sources but were greater when sows were fed organic Se (p<0.05). Except for 24 hours postpartum, the Se concentrations were higher when sows were fed organic Se (p<0.05). Sow serum Se content was greater as Se levels increased from 0.3 ppm to 0.5 ppm at day 110 of gestation, 24 hours postpartum and day 21 of lactation (p<0.05). The pig serum Se concentration increased as the dietary Se level increased (p<0.05) and was higher when the sow dietary Se source was organic (p<0.05). Organic Se 0.5 ppm also had the highest serum Se level at two measured points (p<0.05). Consequently, supplementation with organic Se or 0.5 ppm Se in a gestating diet could improve piglet performance, the Se status of sows and piglets and milk composition, but organic Se at 0.5 ppm is optimal.

Selenium-Enriched Mushroom Powder Enhances Intestinal Health and Growth Performance in the Absence of Zinc Oxide in Post-Weaned Pig Diets.

Simple SummaryThe imminent ban on zinc oxide in pig diets within the European Union is a major challenge facing the swine industry. Commercial weaning is associated with abrupt dietary, environmental and social changes resulting in stress, reduced feed intake and gut developmental issues in the post-weaned pig. Mushrooms are rich in natural bioactives and have long been regarded as a health-promoting food due to their immunomodulatory and antioxidant effects and their ability to modulate the gut microbiota. Mushrooms can become abundant in organic selenium when grown under certain conditions. The present study aimed to determine the optimum Se level, using Se-enriched mushrooms and selenite, in weaned pig diets to enhance intestinal health, performance and antioxidant capacity. Our study demonstrated that 0.3 ppm selenium inclusion, using selenium-enriched mushroom powder, led to positive effects on faecal scores and had similar pig performance compared to zinc oxide during the first 21 days post-weaning. The selenium inclusion level of 0.6 ppm, using selenium-enriched mushroom powder and selenite, enhanced pig performance and aspects of gastrointestinal health during days 21 and 39 post-weaning.This study was conducted to examine the effects of varying selenium (Se) inclusion levels, in the form of Se-enriched mushroom powder (SeMP) and selenite, on post-weaning growth performance (Period 1; day 1–21), intestinal health and antioxidant capacity (Period 2; day 21–39). Weaned pigs were blocked according to live weight, sex and litter of origin and randomly assigned to the following experimental groups: basal (basal + selenite (0.3 ppm Se)); ZnO (basal + ZnO + selenite (0.3 ppm Se)); 0.15 SeMP (basal + SeMP (0.15 ppm Se)); 0.3 SeMP (basal + SeMP (0.3 ppm Se)) and 0.6 SeMP/Sel (basal + SeMP (0.3 ppm Se) + selenite (Sel) (0.3 ppm Se)) with eight replicates/experimental group. After 21 days, the ZnO experimental group was removed from the experiment and the remaining pigs continued on their respective diet until day 39 post-weaning (Period 2). In Period 1, 0.15 SeMP supplementation reduced (p < 0.05) average daily gain (ADG), average daily feed intake (ADFI) and day 21 body weight, and increased (p < 0.05) faecal scores compared to the ZnO group. Supplementation with 0.3 SeMP and 0.6 SeMP/Sel during Period 1 resulted in similar (p > 0.05) ADG, ADFI, gain-to-feed ratio (G:F) and body weight compared to the ZnO group. However, 0.6 SeMP/Sel supplementation increased (p < 0.05) faecal scores compared to the ZnO group. In Period 2, 0.6 SeMP/Sel increased (p < 0.05) ADG, feed efficiency and day 39 body weight compared to the basal group. Supplementation with Se-enriched mushroom powder, at all inclusion levels, increased (p < 0.05) the abundance of Prevotellaceae and Prevotella, decreased (p < 0.05) the abundance of Sporobacter and increased (p < 0.05) the expression of SELENOP in the jejunum compared to the basal group. Lactobacillaceae and Lactobacillus was increased (p < 0.05) in 0.15 SeMP and 0.3 SeMP pigs compared to the basal group. Selenium deposition in muscle and liver tissue increased (p < 0.001) as a function of inclusion level while pigs supplemented with 0.3 ppm organic Se (0.3 SeMP) had an increase (p < 0.05) in total Se in the muscle compared to pigs supplemented with 0.3 ppm inorganic Se (basal). In conclusion, 0.3 SeMP supplementation led to positive effects on faecal scores and had similar pig performance compared to ZnO in Period 1, while the addition of 0.3 ppm selenite to 0.3 SeMP (0.6 SeMP/Sel) in Period 2 led to enhanced pig performance and aspects of gastrointestinal health.