Dietary Se Supplementation Research Articles

Molecular Antioxidant Functions are Enhanced in Atlantic Bluefin Tuna (Thunnus Thynnus, L.) Larvae Fed Selenium-Enriched Rotifers Brachionus Rotundiformis.

Selenium (Se) is an essential trace element for fish with more than 40 selenoproteins identified, many exhibiting antioxidant functions. This study investigated the effect of dietary Se supplementation on physiological parameters, selenoprotein and antioxidant enzyme gene expression in Atlantic bluefin tuna (ABT, Thunnus thynnus) larvae. First-feeding ABT larvae were divided into triplicate groups and fed rotifers Brachionus rotundiformis enriched with five different levels of Se (0, 3, 10, 30, and 100 µg Se·L-1) until 14 days after hatching. Both rotifers and ABT larvae effectively accumulated Se achieving maximum levels in the Se100 treatment (30.05 μg Se·g-1 and 194 ± 38 μg Se·g-1 dry mass, respectively). Larvae showed highest total length when fed Se3 rotifers, whereas flexion index was highest in larvae fed Se10. Selenium supplementation increased the gene expression of selenoproteins gpx1, msrb1, trxr2, selenom, selenop, and selenoe compared to the non-supplemented control (Se0), but only marginal differences were detected between supplementation levels. In contrast, expression of the antioxidant enzymes cat and sod1 were lowest in larvae fed Se100. To conclude, non-Se-enriched rotifers may be suboptimal for first feeding ABT larvae, which showed improved selenoprotein and antioxidant gene expression when fed a diet containing 4.42 μg Se·g-1 dry mass.

Plasma and Colostrum Selenium Statuses of Properly Supplemented Belgian Blue Cows on Commercial Farms and Their Relationship with Sources of Dietary Selenium and Blood Biomarkers

Selenium (Se) is an essential trace element for the health and immunity of cattle. Double-muscled Belgian Blue cows are well known to be prone to nutritional deficiencies. Colostrum Se level is also a key factor to promote immunoglobulin intake in young calves. The main objectives of this study were to assess (1) the plasma and colostrum Se statuses of properly supplemented Belgian Blue cows on commercial farms and (2) the relationship between Se concentrations in plasma and colostrum. The secondary objectives were to assess relationships between plasma or colostrum Se concentrations and dietary Se supplementation as well as blood biomarkers. Blood and colostrum samples were collected from 49 Belgian Blue cows on five commercial farms in Belgium. They received five different rations with Se supplementation ranging from 0.5 to 2 ppm, including 20% to 83% in organic form. Results showed that the average Se concentration was 90 ± 15 µg/L in plasma and 79 ± 26 µg/L in colostrum, consistent with previous studies on well-supplemented cows. No relationship was observed between Se concentrations in plasma and colostrum, suggesting that colostrum Se testing would be a complementary indicator for improving calf Se supplementation. Relationships between plasma or colostrum Se concentrations and dietary Se or blood biomarkers emphasized the complexity of Se metabolism in observational studies under field conditions.

Beyond antioxidants: Selenium and skeletal muscle mitochondria.

The element, Selenium (Se), has an essential nutritive and biological role as a trace mineral known primarily for its vital antioxidant functions as a constituent of the selenoenzyme, glutathione peroxidase. However, Se also has a much more global biological impact beyond antioxidant function. The objective of this review is to present an overview of prior research on the extra-antioxidant effects of Se with a key focus on skeletal muscle mitochondrial energetics. Cognizance of these additional functions of Se is requisite when formulating and recommending dietary supplementation of Se in humans or animals. Chief amongst its myriad of biological contributions, Se influences mitochondrial capacity and function and, subsequently, muscular health. Dietary Se supplementation has been shown to increase skeletal muscle mitochondrial volume density and within some cell lines, Se treatment increases mitochondrial biogenesis and respiratory capacity. In addition, the selenoproteins H, N, W, and O and deiodinases exhibit varying effects on mitochondrial and/or skeletal muscle function. Selenoprotein H enhances mitochondrial biogenesis whereas selenoproteins N and W appear to influence muscle calcium homeostasis which impacts mitochondrial function. Moreover, selenoprotein O's intramitochondrial residence facilitates Se's redox function. Deiodinases regulate thyroid hormone activation which impacts muscle cell regeneration, metabolism, and reactive oxygen species production. Although the precise relationships between dietary Se and skeletal muscle mitochondria remain unclear, previous research constitutes a firm foundation that portends promising new discoveries by future investigations.

Selenium and selenoproteins: their function and development of selenium‐rich foods

SummarySelenium (Se) is a nutrient related to human physiological processes and an essential trace element that has attracted considerable attention because of its antioxidant, immune and other functions. Se deficiency can cause all sorts of diseases and dysfunctions in the human tissues, but excessive intake of Se can also cause poisoning and injury. With lower toxicity and higher utilisation than inorganic Se, organic Se is recommended in the framework of a balanced diet. Compared with pharmaceutical supplementation, dietary Se supplementation is more acceptable to the masses. Thus, Se‐rich foods and selenoproteins enriched with organic Se have become a hot spot for current research. In living organisms, Se often exists in the form of selenoproteins (more than 25); for example, selenocysteine and selenomethionine are the common chemical forms of Se amino acids. And most of Se's physiological functions depend on the participation of selenoproteins. This paper reviews the physiological processes of Se, the development and utilisation of Se‐enriched foods, and the research on the properties of selenoproteins. Some suggestions and prospects for developing Se‐rich food in the future are also provided.

Dietary supplementation with selenomethionine enhances antioxidant capacity and selenoprotein gene expression in layer breeder roosters

This study's objective was to investigate the effects of dietary Se (in the form of selenomethionine) on the antioxidant activity and selenoprotein gene expressions in layer breeder roosters. One hundred and eighty, 36-wk-old Jingfen layer breeder roosters were randomly allocated to one of 5 dietary treatments (0, 0.25, 0.5, 1, or 2 mg/kg Se) for 6 wk on a corn-soybean meal-based diet. Antioxidant parameters and selenoprotein gene expressions were assessed at the end of the experiment. The results showed that Se supplementation significantly increased the activity of T-SOD, CAT, GSH-Px, and superoxide anion scavenging ability in plasma (P ≤ 0.05), and activities of T-SOD, CAT, GSH-Px, superoxide anion scavenging ability, and hydroxyl radical scavenging ability in the liver, kidney, and testis (P < 0.05). Moreover, MDA levels were significantly reduced in plasma, liver, kidney, and testis (P < 0.01), compared to the control group. Furthermore, the dietary administration of Se significantly increased TrxR2 and GPx4 mRNA levels in kidney and testis, and ID1 mRNA levels in liver and kidney. Most of the antioxidant parameters and selenoprotein-related gene expressions significantly increased, and MDA significantly decreased at dietary supplementation with 0.5 mg/kg Se. Whereas a higher dose of Se level (1 or 2 mg/kg) inhibited the activities of some of the antioxidant enzymes and selenoprotein-related gene expressions in selected tissues. In conclusion, dietary Se supplementation with 0.5 mg/kg significantly improved roosters’ antioxidant status and selenoprotein-related gene expression in liver, kidney, and testis, while higher doses led to inhibit these; dietary Se might increase reproductive performance by enhancing their antioxidant status in roosters.

Effects of enrichment Artemia with organic selenium and essential fatty acids on growth performance and fatty acid composition of barramundi (Lates calcarifer) larvae

A feeding factorial experiment was conducted, in which Artemia was enriched with two organic selenium (Se) concentrations (0, 12 mg/L) and three highly unsaturated fatty acids (HUFA) levels (0, 0.3 and 0.6 g/L) to produce six dietary treatments, labelled as H0, H03, H06, H0S; H03S and H06S. The diets were fed to barramundi larvae (11 day after hatching) for 15 days to investigate the combined effects of selenium and HUFA on growth performance, fatty acid composition, skeletal deformities and stress resistance of the larvae. The results showed that enriching Artemia with Se significantly improved the final weight and specific growth rate of the larvae fed non or highest HUFA enrichment levels (P < 0.05). No differences were observed in survival of the larvae fed enriched HUFA diets, but they were significantly higher than those fed unenriched HUFA groups. Dietary Se supplementation significantly increased larval n-3 HUFA and DHA contents. High mortalities were recorded in the larvae fed unenriched HUFA diets, whereas Se supplementation significantly increased the survival of the larvae fed high HUFA level. Fish fed unenriched HUFA Artemia showed significantly higher skeletal deformities than those fed other diets. The results thus indicated the beneficial effects of dietary Se in preventing the reduced growth and stress resistance in the barramundi fed HUFA inclusion diets.

Embracing nanotechnology for selenium application in aquafeeds

AbstractSelenium (Se) is an important micronutrient that has been used in aquafeeds for the normal growth, welfare and health of aquatic animals. Through nanotechnology, Se can be converted into nanoparticles that are more bioavailable, utilized and absorbed by aquatic animals. However, this is still a new and emerging area of research in aquafeeds. This paper aims to review the effect of Se and Se nanoparticles (Se‐NPs) application in aquafeeds on aquatic animals. Specifically, different compounds of Se, requirement levels by different species, effects on animal growth, physiology, antioxidant capacity and immune response have been highlighted. The review shows that the application of Se in aquafeeds could improve the growth performance, physiology, antioxidant enzymes, immunity and disease resistance in aquatic animals. However, the effectiveness could be highly influenced by the source of Se, aquaculture species and administration quantity. Through nanotechnology, the utilization and absorption of Se could be improved while reducing its toxicity. Therefore, Se‐NPs present an efficient way to utilize nutrients in aquafeeds. Important gaps, however, exist in the current knowledge, particularly with regard to the response of shrimps and crustaceans to dietary supplementation of Se and Se‐NPs as most of the existing studies have focused on fish species. Also, some species of economic importance and life stages have not been investigated, which hinders the embracement of nanotechnology in aquafeeds production.

Dietary selenium requirement of triploid rainbow trout ( Oncorhynchus mykiss ) based on selenium yeast supplementation

Selenium(Se) is a biological essential trace element that affects the growth and health of fish. The present study aimed to explore the dietary Se requirement of triploid rainbow trout using Se-yeast supplement. The levels of Se added to the basal diet were 0(Se0), 0.1(Se0.1), 0.3(Se0.3), 0.5(Se0.5), 1.0(Se1.0), 4.0(Se4.0) and 16.0(Se16.0) mg Se/kg diet respectively. Results showed that the fish fed Se4.0 diet had significantly higher weight gain and lower oxidative stress compared with the fish fed Se16.0 and Se0 diets. The optimal dietary Se requirement of triploid rainbow trout was 3.53 mg/kg based on broken-line regression of growth performance. Dietary Se supplementation significantly increased the expression level of selenoprotein genes both in liver (GPX1a, GPX1b1, GPX1b2, SelK, SelP, SelT1, SelT2, SelWl, TrxR3a, SelU) and in muscle (GPX1a, GPX1b2, SelK, SelP, SelU, SelWl, TrxR3b, SelN, MsrB1Al). The minimum dietary Se level was 2.19 or 1.28 mg/kg when the mRNA level of all these selenoproteins reached a plateau in muscle or liver respectively. In conclusion, based on broken-line regression of growth performance and sigmoidal regression of selenoprotein genes expression in muscle and liver, dietary Se requirement of triploid rainbow trout was 3.53, 2.19 and 1.28 mg/kg respectively.

Arsenic retention in erythrocytes and excessive erythrophagocytosis is related to low selenium status by impaired redox homeostasis

Arsenic (As) contamination in drinking water is a global public health problem. Epidemiological studies have shown that selenium (Se) deficiency is associated with an increasing risk of arsenism. However, the association between Se status and As retention in erythrocytes and mechanisms underlying this association have not been fully investigated. In the present study, a total of 165 eligible subjects were recruited and As was found to accumulate in blood mainly by retention in erythrocytes. Retention of As in erythrocytes was negatively correlated with Se status, antioxidant parameters related to Se and As methylation capacity, but positively correlated with the protein-binding capacity of As. Additionally, erythrocytes isolated from subjects with low Se status exhibited cellular damage along with lower protein levels of CD47, which could be aggravated by hydrogen peroxide treatment. Consistent with the human study, the erythrocytes from mice with sub-chronic As exposure exhibited similar cellular damage and shown to be phagocytosed by splenic macrophages, and these effects were mitigated by dietary Se supplementation. Furthermore, hydrogen peroxide treatment induced excessive phagocytosis of erythrocytes with As exposure by splenic macrophages, while co-treating erythrocytes with the reducing agent, N-Acetyl-l-cysteine, mitigated this excessive erythrophagocytosis. Hyperactivation of the NFκB pathway was also detected in splenic macrophages after excessive erythrophagocytosis. In conclusion, this study found that low Se status involving impaired redox homeostasis increased As retention in erythrocytes, which were subsequently phagocytosed by splenic macrophages and led to an increased inflammatory status of splenic macrophages. These findings provide insight into physiological features of arsenism related to Se status and redox homeostasis.

Broiler meat production as affected by dietary supplemental hydroxy-selenomethionine

Selenium (Se) is essential and usually deficient in corn-soy feeds for broiler chickens. Hydroxy-selenomethionine (OH-SeMet) is a commercial organic source that has not been thoroughly evaluated as a single supplemental source of Se. The objective of this study was to evaluate the increasing dietary Se supplementation from OH-SeMet on broiler growth performance, meat yields, wooden breast (WB) and glutathione peroxidase responses in tissues. A total of 1,500 Cobb vs. Cobb 500 slow feathering one-day-old male chicks were allocated to five treatments with 12 replicates of 25 broilers each in a 3-phase feeding program from d 1 to 42 (0.0, 0.15, 0.30, 0.45 and 0.60 mg/kg of Se supplemented from OH-SeMet). Supplemental Se levels were chosen in order to provide a robust dose-response adjustment and were based on known deficient and excessive dietary contents for broiler chickens. The non-supplemented starter, grower, and finisher feeds had analyzed 0.03, 0.03, and 0.02 mg/kg Se, respectively. At 35 and 42 d of age, five broilers per pen were processed for meat evaluation and scored for WB. Samples from blood, liver, jejunum, and ileum as well as breast meat samples were taken at 42 d for evaluation of glutathione peroxidase (GSH-Px) activity and lipid oxidation (TBARS), whereas breast meat was also analyzed for cooking loss (CL) and water-holding capacity (WHC). Statistical analysis was conducted using the quadratic polynomial regression model. Increasing Se from OH-SeMet led to quadratic increases (P < 0.05) in BWG from d 1 to 42, with optimal concentration at 0.47 mg/kg Se as well as optimized estimations for FCR at 0.42 mg/kg Se. Dietary Se that maximized carcass and breast meat yields at 42 d were 0.41 and 0.48 mg/kg Se, respectively (P < 0.05). Dietary Se that maximized GSH-Px activity in erythrocytes was at 0.27 mg/kg (P < 0.05). No effects of Se were observed on WB scores at 35 and 42 d of age, CL and WHC as well as on TBARS in intestine, liver and breast muscle samples (P > 0.05). Supplementation of Se from OH-SeMet in corn-soy feeds improved broiler performance, carcass and breast yields. Average Se that optimized BWG was 0.48 mg/kg, whereas 0.46 mg/kg was needed for carcass and 0.40 mg/kg for breast yield. These are total Se contents acceptable in the European Union and frequently below commercially used contents in countries that do not have a limit on minerals in feeds.

Hydroxy Selenomethionine Alleviates Hepatic Lipid Metabolism Disorder of Pigs Induced by Dietary Oxidative Stress via Relieving the Endoplasmic Reticulum Stress.

This study used 40 castrated male pigs to determine the protective effects of a new selenium molecule (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced hepatic lipid metabolism disorder, and corresponding response of selenotranscriptome. The pigs were randomly grouped into 5 dietary treatments and fed a basal diet formulated with either normal corn and oils or oxidized diet in which the normal corn and oils were replaced by aged corn and oxidized oils, and supplemented with OH-SeMet at 0.0, 0.3, 0.6 and 0.9 mg Se/kg for a period of 16 weeks (n = 8). The results showed that DOS induced liver damage, increased serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels, decreased serum triacylglycerol (TG) level, suppressed antioxidant capacity in the liver, and changed lipid metabolism enzyme activity, thus causing lipid metabolism disorder in the liver. The DOS-induced lipid metabolism disorder was accompanied with endoplasmic reticulum (ER) stress, changes in lipid metabolism-related genes and selenotranscriptome in the liver. Dietary Se supplementation partially alleviated the negative impact of DOS on the lipid metabolism. These improvements were accompanied by increases in Se concentration, liver index, anti-oxidative capacity, selenotranscriptome especially 11 selenoprotein-encoding genes, and protein abundance of GPX1, GPX4 and SelS in the liver, as well as the decrease in SelF abundance. The Se supplementation also alleviated ER stress, restored liver lipid metabolism enzyme activity, increased the mRNA expression of lipid synthesis-related genes, and decreased the mRNA levels of lipidolysis-related genes. In conclusion, the dietary Se supplementation restored antioxidant capacity and mitigated ER stress induced by DOS, thus resisting hepatic lipid metabolism disorders that are associated with regulation of selenotranscriptome.

Effects of selenylation modification on the antioxidative and immunoregulatory activities of polysaccharides from the pulp of Rose laevigata Michx fruit

Selenylation modification has been widely utilized to improve the activity of polysaccharides and to develop novel sources of selenium (Se) supplements. A purified pulp polysaccharide of Rose laevigata Michx fruit (PPRLMF-2) was selenized into Se-PPRLMF-2 in this study. PPRLMF-2 + Se was formulated by Na2SeO3 according to the Se content of Se-PPRLMF-2. To investigate the effects of selenylation modification on the structure and functions of PPRLMF-2, the characteristics, antioxidative and immunoregulatory activities of PPRLMF-2 before and after selenylation were compared. The results showed that compared with PPRLMF-2, Se-PPRLMF-2 became an irregular fibrous network, and its Mw decreased and C-6 substitution predominated in 13C NMR spectra. Se-PPRLMF-2 significantly increased chemical antioxidant activity and reduced the oxidative damage of erythrocytes, which was not due to Se alone. Se-PPRLMF-2 significantly increased immunomodulatory activity on macrophages, which was related to Se alone. Se-PPRLMF-2 could be a good potential source of antioxidants, immune enhancers and dietary Se supplements.

Gpx4, Selenov, and Txnrd3 Are Three Most Testis-Abundant Selenogenes Resistant to Dietary Selenium Concentrations and Actively Expressed During Reproductive Ages in Rats.

Almost all selenogenes are expressed in the testis, and those have the highest and constant expressions will be the primary candidates for functional analysis of selenium (Se) in male reproduction. This study aimed to profile the mRNA expressions of the testis-abundant selenogenes of rat models in responses to growth and dietary Se concentrations. Forty-eight weaning SD male rats were fed Se deficient basal diet (BD) for 5weeks and then randomly grouped (n = 12/group) for being fed BD or BD plus 0.25, 3, or 5mg Se/kg for 4 more weeks before sacrifice. Abundances of selenogenomic mRNAs in the liver and testis were determined with relative qPCR and those of the testis-abundant selenogenes in 13 kinds of tissues were assayed with a molecular beacon-based qPCR. Spatiotemporal expressions of rat selenogenome were also analyzed with the RNA-Seq transcriptomic data published by NCBI. mRNA abundances of glutathione peroxidase 4 (Gpx4), nuclear Gpx4 (nGpx4), selenoprotein V (Selenov), and thioredoxin reductase 3 (Txnrd3) in the testis were significantly higher than that in any other tissues (P < 0.05). Moreover, testicular mRNA abundances of Gpx4, Selenov, and Txnrd3 were not affected by levels of dietary Se supplementation (P > 0.05), and much higher at 6-21weeks old than at 2 and 104weeks old (P < 0.05). The result showed that Gpx4, Selenov, and Txnrd3 were most highly expressed in the testis of rats especially at reproductive ages and resistant to the impact of dietary Se levels, which suggested their specific importance in male reproduction.

Effects of Selenium as a Dietary Source on Performance, Inflammation, Cell Damage, and Reproduction of Livestock Induced by Heat Stress: A Review.

Heat stress as a result of global warming has harmful consequences for livestock and is thus becoming an urgent issue for animal husbandry worldwide. Ruminants, growing pigs, and poultry are very susceptible to heat stress because of their fast growth, rapid metabolism, high production levels, and sensitivity to temperature. Heat stress compromises the efficiency of animal husbandry by affecting performance, gastrointestinal health, reproductive physiology, and causing cell damage. Selenium (Se) is an essential nutritional trace element for livestock production, which acts as a structural component in at least 25 selenoproteins (SELs); it is involved in thyroid hormone synthesis, and plays a key role in the antioxidant defense system. Dietary Se supplementation has been confirmed to support gastrointestinal health, production performance, and reproductive physiology under conditions of heat stress. The underlying mechanisms include the regulation of nutrient digestibility influenced by gastrointestinal microorganisms, antioxidant status, and immunocompetence. Moreover, heat stress damage to the gastrointestinal and mammary barrier is closely related to cell physiological functions, such as the fluidity and stability of cellular membranes, and the inhibition of receptors as well as transmembrane transport protein function. Se also plays an important role in inhibiting cell apoptosis and reducing cell inflammatory response induced by heat stress. This review highlights the progress of research regarding the dietary supplementation of Se in the mitigation of heat stress, addressing its mechanism and explaining the effect of Se on cell damage caused by heat stress, in order to provide a theoretical reference for the use of Se to mitigate heat stress in livestock.

Effects of different selenium sources on duodenum and jejunum tight junction network and growth performance of broilers in a model of fluorine-induced chronic oxidative stress

The protective effects and underlying molecular mechanisms of sodium selenite (SS) and selenomethionine (SM) against chronic oxidative stress-induced duodenum and jejunum tight junction (TJ) network disturbance and growth inhibition of broilers were investigated in the current experiment. At the age of 1 d, 720 Lingnan Yellow broiler chicks were allocated to 4 experimental diets (with 6 replicates per diet and 30 birds per replicate) and offered either a control diet (fluorine [F] 23 mg/kg, control [CoN] group) or test diets (800 mg/kg F, high F [HF] group; 800 mg/kg F+0.15 mg selenium [Se]/kg as SS [SS group] or SM [SM group]) for 56 d. The results showed that HF group could induce chronic oxidative stress and subsequently increased (P < 0.05) proinflammatory cytokines levels of duodenum and jejunum in comparison with the CoN group. Increased proinflammatory cytokines levels of HF group promoted myosin light chain kinase (MLCK) transcription, thus leading to a decrease (P < 0.05) in TJ proteins expression of duodenum and jejunum when compared with the CoN group. A reduction of TJ proteins expression destroyed the TJ structures in the HF group, which in turn increased intestinal mucosal permeability of duodenum and jejunum and ultimately induced growth inhibition of broilers. Dietary Se supplementation could ameliorate HF-induced duodenum and jejunum TJ network impairment and growth retardation of broilers, potentially by increasing (P < 0.05) the glutathione peroxidase and thioredoxin reductase activities, reducing (P < 0.05) the reactive oxygen species and malondialdehyde levels, regulating the secretion of proinflammatory cytokines, and mediating the transcription level of MLCK in the duodenum and jejunum. Additionally, our data also suggested that the protective effects of SM were superior to those of SS. This study will provide a theoretical basis for developing SM into an efficient protective agent for intestinal mucosal barrier in poultry.

Isolation and identification of Monascus and evaluation of its selenium accumulation

Selenium (Se) plays an important role in human physiological metabolism. Se-enriched microorganism could be a remedy for Se-deficiency related diseases. Monascus are acid-resistant, saprophytic, filamentous and edible fungi which are widely used in the food fermentation industry. However, studies on Se-biofortification almost ignore the possibility of applications in Monascus. In this work, a Monascus purpureus, M12 was isolated from the collected samples and used for Se-resistant testing and Se-enrichment domestication. The results showed M12 hold strong ability to tolerate exogenously applied inorganic Se. At all concentrations of sodium selenite, the strain can enter the growth boom period within 2 d, without a lag period. The total selenium content in M12 was between 1400 and 2000 μg/g. When the concentration of sodium selenite was between 40 and 90 μg/mL, the utilization rate of inorganic Se reached 99%. The optimal conditions for Se accumulation were also optimized by determining the total Se, organic Se content in fungal cell. The Se enrichment ability of Monascus provides a new potential for dietary Se supplementation.

Effects of maternal and progeny dietary selenium supplementation on growth performance and antioxidant capacity in ducklings

This study evaluated the effects of selenium (Se) supplementation in maternal and offspring diets on performance and antioxidant capacity of ducklings aged from 0 to 2 wk. A total of 144 female Longyan duck breeders aged 22-wk were allotted into 2 treatments and fed a control diet or a 0.16 mg Se/kg supplemented diet. At 40-wk, 120 offspring from each treatment were divided into 2 groups, with 6 replicates of 10 birds. Using a 2 × 2 factorial design, ducklings from each maternal dietary treatment were assigned to a control diet or a 0.16 mg Se/kg supplemented diet from hatch to 2-wk. Compared with Se-deficient diet, maternal diet supplemented with 0.16 mg Se/kg increased the BW of hatchlings (P < 0.01). There were interactions between maternal and progeny diet with 0.16 mg Se/kg in BW of ducklings aged 2 wk and BW gain (BWG) as ducklings from maternal Se/progeny none treatment had the lightest BW and BWG (P < 0.01). Maternal diet with 0.16 mg Se/kg decreased plasma concentration of uric acid and insulin-like growth factor 1 (P < 0.01), and progeny diet supplemented with 0.16 mg Se/kg increased the activities of glutathione peroxidase 3 (GPx3) in plasma and glutathione peroxidase 1 in erythrocyte (P < 0.01). Maternal diet with 0.16 mg Se/kg increased (P < 0.05) the hepatic activity of total superoxide dismutase (T-SOD). Progeny diet supplemented with 0.16 mg Se/kg increased (P < 0.01) hepatic activity of GPx3 and decreased (P < 0.01) the hepatic concentration of malondialdehyde. Interactions were detected between maternal and progeny diet with 0.16 mg Se/kg in hepatic activity of T-SOD and maternal and progeny diet supplemented with Se displayed the highest hepatic activity of T-SOD (P < 0.05). Overall, Se supplementation in the diet of duck breeders and offspring increased the antioxidant capacity of ducklings. Maternal Se supplementation increased the BW of hatchlings, whereas maternal and progeny dietary Se supplementation did not affect the BWG of ducklings aged from 0 to 2 wk. Se supplementation with additional 0.16 mg/kg in the diet of duck breeders and offspring displayed beneficial effects particularly on the antioxidant capacity in ducklings.

Selenoproteins Protect Against Avian Liver Necrosis by Metabolizing Peroxides and Regulating Receptor Interacting Serine Threonine Kinase 1/Receptor Interacting Serine Threonine Kinase 3/Mixed Lineage Kinase Domain-Like and Mitogen-Activated Protein Kinase Signaling.

Liver necroptosis of chicks is induced by selenium (Se)/vitamin E (VE) deficiencies and may be associated with oxidative cell damage. To reveal the underlying mechanisms of liver necrosis, a pool of the corn–soy basal diet (10 μg Se/kg; no VE added), a basal diet plus all-rac-α-tocopheryl acetate (50 mg/kg), Se (sodium selenite at 0.3 mg/kg), or both of these nutrients were provided to day-old broiler chicks (n = 40/group) for 6 weeks. High incidences of liver necrosis (30%) of chicks were induced by –SE–VE, starting at day 16. The Se concentration in liver and glutathione peroxidase (GPX) activity were decreased (P < 0.05) by dietary Se deficiency. Meanwhile, Se deficiency elevated malondialdehyde content and decreased superoxide dismutase (SOD) activity in the liver at weeks 2 and 4. Chicks fed with the two Se-deficient diets showed lower (P < 0.05) hepatic mRNA expression of Gpx1, Gpx3, Gpx4, Selenof, Selenoh, Selenok, Selenom, Selenon, Selenoo, Selenop, Selenot, Selenou, Selenow, and Dio1 than those fed with the two Se-supplemented diets. Dietary Se deficiency had elevated (P < 0.05) the expression of SELENOP, but decreased the downregulation (P < 0.05) of GPX1, GPX4, SELENON, and SELENOW in the liver of chicks at two time points. Meanwhile, dietary Se deficiency upregulated (P < 0.05) the abundance of hepatic proteins of p38 mitogen-activated protein kinase, phospho-p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, phospho-c-Jun N-terminal kinase, extracellular signal-regulated kinase, phospho-mitogen-activated protein kinase, receptor-interacting serine-threonine kinase 1 (RIPK1), receptor-interacting serine-threonine kinase 3 (RIPK3), and mixed lineage kinase domain-like (MLKL) at two time points. In conclusion, our data confirmed the differential regulation of dietary Se deficiency on several key selenoproteins, the RIPK1/RIPK3/MLKL, and mitogen-activated protein kinase signaling pathway in chicks and identified new molecular clues for understanding the etiology of nutritional liver necrosis.

Selenium Modulates the Allergic Response to Whey Protein in a Mouse Model for Cow's Milk Allergy.

Cow’s milk allergy is a common food allergy in infants, and is associated with an increased risk of developing other allergic diseases. Dietary selenium (Se), one of the essential micronutrients for humans and animals, is an important bioelement which can influence both innate and adaptive immune responses. However, the effects of Se on food allergy are still largely unknown. In the current study it was investigated whether dietary Se supplementation can inhibit whey-induced food allergy in an animal research model. Three-week-old female C3H/HeOuJ mice were intragastrically sensitized with whey protein and cholera toxin and randomly assigned to receive a control, low, medium or high Se diet. Acute allergic symptoms, allergen specific immunoglobulin (Ig) E levels and mast cell degranulation were determined upon whey challenge. Body temperature was significantly higher in mice that received the medium Se diet 60 min after the oral challenge with whey compared to the positive control group, which is indicative of impaired anaphylaxis. This was accompanied by reductions in antigen-specific immunoglobulins and reduced levels of mouse mast cell protease-1 (mMCP-1). This study demonstrates that oral Se supplementation may modulate allergic responses to whey by decreasing specific antibody responses and mMCP-1 release.

Effect of supplementing hydroxy selenomethionine on meat quality of yellow feather broiler

This study was conducted to evaluate the effect of supplementing hydroxy selenomethionine (OH-SeMet) on performance, selenium (Se) deposition in the breast muscle, quality and oxidative stability, and expression of selenoprotein encoding genes of breast meat of the native slow-growing yellow-feathered broiler birds. A total of 375 one-day-old local yellow male birds were randomly assigned into 5 dietary treatments, supplemented with Se 0.0, 0.2, 0.4, 0.6, and 0.8 mg/kg in the form of OH-SeMet. Each treatment consisted of 5 replicates and each replicate had 15 birds, the birds were fed on basal diet containing corn and soybean meal, and the experiment lasted for 63 d. The results showed that dietary Se supplementation linearly increased (P < 0.001) Se contents in both serum and muscle, no significant changes (P > 0.05) were observed on growth performance, yield of breast, meat color, and intramuscular fat deposition of the breast muscle. Dietary Se addition improved water-holding capacity, the pH24h value, and tenderness of breast muscle, evidenced by a linear decreases of shear force (P < 0.05), accompanied by lower thiobarbituric acid reactive substances and higher glutathione reductase activity. The mRNA abundance of selenoprotein encoding genes also responded to dietary Se levels. It is concluded that, dietary supplementation with OH-SeMet improved muscular Se deposition and meat quality of the native yellow birds, with enhanced antioxidant capability and regulation in selenogenome.