Effects of selenium source and level on growth performance, tissue selenium concentrations, antioxidation, and immune functions of heat-stressed broilers

Selenium deficiency-induced multiple tissue damage with dysregulation of immune and redox homeostasis in broiler chicks under heat stress

Broiler chicks are fast-growing and susceptible to dietary selenium (Se) deficiency. This study sought to reveal the underlying mechanisms of how Se deficiency induces key organ dysfunctions in broilers. Day-old male chicks (n=6 cages/diet, 6 chicks/cage) were fed with a Se-deficient diet (Se-Def, 0.047 mg Se/kg) or the Se-Def+0.3 mg Se/kg (Control, 0.345 mg Se/kg) for 6 weeks. The serum, liver, pancreas, spleen, heart, and pectoral muscle of the broilers were collected at week 6 to assay for Se concentration, histopathology, serum metabolome, and tissue transcriptome. Compared with the Control group, Se deficiency induced growth retardation and histopathological lesions and reduced Se concentration in the five organs. Integrated transcriptomics and metabolomics analysis revealed that dysregulation of immune and redox homeostasis related biological processes and pathways contributed to Se deficiency-induced multiple tissue damage in the broilers. Meanwhile, four metabolites in the serum, daidzein, epinephrine, L-aspartic acid and 5-hydroxyindoleacetic acid, interacted with differentially expressed genes with antioxidative effects and immunity among all the five organs, which contributed to the metabolic diseases induced by Se deficiency. Overall, this study systematically elucidated the underlying molecular mechanisms in the pathogenesis of Se deficiency-related diseases, which provides a better understanding of the significance of Se-mediated heath in animals.

Advances in selenium supplementation: From selenium-enriched yeast to potential selenium-enriched insects, and selenium nanoparticles

Selenium (Se) is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis. This review surveys the role of Se in the environment, plants and animal bodies, and discusses data on Se biofortification with different sources of supplementation, from inorganic to organic forms, with special focus on Se-enriched yeast (Se-yeast). Although Se-yeast remains one of the main sources of organic Se, other emerging and innovative sources are reviewed, such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition. Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets. Se-nanoparticles are also discussed, as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms, compared to selenite and selenate. We also provide up to date information on the legal framework in the EU, USA, and Canada of Se that is contained in feed additives. From the scientific evidence available in the literature, it can be concluded that among the inorganic forms, sodium selenite is still one of the main options, whereas Se-yeast remains the primary organic form. However, other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Effects of Selenium Yeast on Egg Quality, Plasma Antioxidants, Selenium Deposition and Eggshell Formation in Aged Laying Hens

Internal egg and eggshell quality are often deteriorated in aging laying hens, which causes huge economic losses in the poultry industry. Selenium yeast (SY), as an organic food additive, is utilized to enhance laying performance and egg quality. To extend the egg production cycle, effects of selenium yeast supplementation on egg quality, plasma antioxidants and selenium deposition in aged laying hens were evaluated. In this study, five hundred and twenty-five 76-week-old Jing Hong laying hens were fed a selenium-deficient (SD) diet for 6 weeks. After Se depletion, the hens were randomly divided into seven treatments, which included an SD diet, and dietary supplementation of SY and sodium selenite (SS) at 0.15, 0.30, and 0.45 mg/kg to investigate the effect on egg quality, plasma antioxidant capacity, and selenium content in reproductive organs. After 12 weeks of feeding, dietary SY supplementation resulted in higher eggshell strength (SY0.45) (p < 0.05) and lower shell translucence. Moreover, organs Se levels and plasma antioxidant capacity (T-AOC, T-SOD, and GSH-Px activity) were significantly higher with Se supplementation (p < 0.05). Transcriptomic analysis identified some key candidate genes including cell migration inducing hyaluronidase 1 (CEMIP), ovalbumin (OVAL), solute carrier family 6 member 17 (SLC6A17), proopiomelanocortin (POMC), and proenkephalin (PENK), and potential molecular processes (eggshell mineralization, ion transport, and eggshell formation) involved in selenium yeast's effects on eggshell formation. In conclusion, SY has beneficial functions for eggshell and we recommend the supplementation of 0.45 mg/kg SY to alleviate the decrease in eggshell quality in aged laying hens.

Dietary selenium levels modulates antioxidant, cytokine and immune response and selenoproteins mRNA expression in rats under heat stress condition

BACKGROUND

Higher environmental temperature is a major abiotic stress factor for animals and human beings. The selenium (Se) is an important trace mineral having diverse health promoting effects under stress conditions. However, studies on dietary requirement of selenium under prolonged heat stress condition are lacking. Present study discern the effect of higher dietary Se levels on antioxidant, cytokine, haemato-biochemical profile, and immune response, and the selenoproteins mRNA expression in rats under prolonged heat stress (HS) condition.

METHODS

Weaned Wistar rats (4 wk age; 67.6 ± 1.53 g BW; n = 72) housed under thermoneutral (TN) or HS conditions and fed with purified diets containing three graded Se levels were divided in six experimental groups. The groups were 1) TN control with 138 ppb Se (TN_CON), 2) HS control with 138 ppb Se (HS_CON), 3) TN with higher Se @ 291 ppb (TN_Se1), 4) HS with higher Se @ 291 ppb (HS_Se1) 5) TN with higher Se @ 460 ppb (TN_Se2), 6) HS with higher Se @ 460 ppb (HS_Se2). Rats in all the six groups were maintained in TN environmental conditions (57.3 ± 0.22 temperature humidity index; THI) for initial 28 days period. Subsequently, rats of HS groups were exposed to 77.0 ± 0.11 THI for 6 h/d in a psychrometric chamber for last fourteen days.

RESULTS

Higher dietary Se (291 and 460 ppb) significantly improved the blood hemoglobin concentration and reduced serum alanine aminotransferase activity of rats under HS conditions. The serum triiodothyronine and insulin levels were significantly higher in high dietary Se groups irrespective of the environmental conditions. Similarly, the serum reduced glutathione levels, and catalase and superoxide dismutase enzyme activity were increased and malondialdehyde levels were reduced in high dietary Se groups irrespective of stress conditions. The glutathione peroxidase (GPx) activity was significantly higher in 460 ppb dietary Se groups as compared to other groups. The serum pro-inflammatory cytokine interleukin (IL)- 1 was declined, whereas the anti-inflammatory cytokine IL-10 level was increased in high dietary Se fed rats under both HS and TN conditions with 460 ppb dietary Se groups showing pronounced effects. Further, there was heat stress- and dietary Se level dependent- up regulation in hepatic GPx and iodothyronine deiodinase-II mRNA expression and similar pattern was noticed in hepatic thioredoxin reductase mRNA expression. The selenoprotein-P mRNA expression was up regulated in 460 ppb Se fed HS group as compared to CON and Se1_C groups. High dietary Se improved the humoral immune response 7d after antigen inoculation under HS conditions whereas cell-mediated immune response was augmented in rats fed higher Se under TN condition.

CONCLUSION

It is concluded that under prolonged heat stress conditions the dietary requirement of Se may be increased to 460 ppb for improving the antioxidant status and humoral immune response, cytokine levels, modulating the thyroid and insulin hormone, and the selenoproteins mRNA expression of rats.

Selenium Deficiency Dysregulates One-Carbon Metabolism in Nutritional Muscular Dystrophy of Chicks

BACKGROUND

Nutritional muscular dystrophy (NMD) in animals is induced by dietary selenium (Se) deficiency.

OBJECTIVES

This study was conducted to explore the underlying mechanism of Se deficiency-induced NMD in broilers.

METHODS

One-day-old male Cobb broilers (n = 6 cages/diet, 6 birds/cage) were fed a Se-deficient diet (Se-Def, 47 μg Se/kg) or the Se-Def supplemented with 0.3 mg Se/kg (control) for 6 wk. Thigh muscles of broilers were collected at week 6 for measuring Se concentration, histopathology, and transcriptome and metabolome assays. The transcriptome and metabolome data were analyzed with bioinformatics tools and other data were analyzed with Student's t tests.

RESULTS

Compared with the control, Se-Def induced NMD in broilers, including reduced (P < 0.05) final body weight (30.7%) and thigh muscle size, reduced number and cross-sectional area of fibers, and loose organization of muscle fibers. Compared with the control, Se-Def decreased (P < 0.05) the Se concentration in the thigh muscle by 52.4%. It also downregulated (P < 0.05) GPX1, SELENOW, TXNRD1-3, DIO1, SELENOF, H, I, K, M, and U by 23.4-80.3% in the thigh muscle compared with the control. Multi-omics analyses indicated that the levels of 320 transcripts and 33 metabolites were significantly altered (P < 0.05) in response to dietary Se deficiency. Integrated transcriptomics and metabolomics analysis revealed that one-carbon metabolism, including the folate and methionine cycle, was primarily dysregulated by Se deficiency in the thigh muscles of broilers.

CONCLUSIONS

Dietary Se deficiency induced NMD in broiler chicks, potentially with the dysregulation of one-carbon metabolism. These findings may provide novel treatment strategies for muscle disease.

Hypocholesterolemic, Antioxidative, and Anti-Inflammatory Effects of Dietary Spirulina platensisis Supplementation on Laying Hens Exposed to Cyclic Heat Stress

This study aimed to investigate the role of dietary Spirulina platensis (SP) supplementation in relieving the negative impacts of heat stress (HS) on the productive performance, cholesterol profile, redox status, and inflammatory cytokines of laying hens. A total of 288, 45-wk-old and 1550.7 ± 2.3 g initial body weight, HY-Line W-36 laying hens were housed in two environmental-controlled compartments. Layers were allotted to eight treatments of a two × four factorial design, with six replicates containing six birds per treatment. The temperature in one of the compartments was kept at a thermoneutral condition (24 °C group), while the temperature in the other compartment was raised to a cyclic heat stress of 35 °C from 9:00 a.m. to 5.00 p.m. (35 °C group). Layers in each compartment were fed on one of four experimental diets, containing 0%, 3%, 6%, or 9% SP (SP groups). The trial continued for five weeks. As a result of this study, exposure of laying hens to cyclic HS resulted in a significant (p < 0.05) increase in the total cholesterol (CH), low-density lipoprotein-CH, liver- and egg yolk-CH, ceruloplasmin, malondialdehyde, interleukins (IL-1β and IL-6), and tumor necrosis factor-α, and a significant (p < 0.05) decrease in the high-density lipoprotein-CH, total antioxidant capacity, and reduced glutathione levels. HS negatively (p < 0.05) affected the hen−day egg production (EP, 90.5% vs. 77.0%), egg weight (EW, 61.8 g vs. 56.8 g), feed intake (FI, 111.6 g vs. 101.5 g) and feed conversion ratio (FCR, 2.00 vs. 2.37). As SP levels increased in layer diets, a linear (p < 0.05) improvement response in most of the parameters was obtained in both HS and non-HS layers, recording the best results with 9% SP (e.g., 78.8% vs. 87.6% EP, 56.7 g vs. 61.9 g EW, 103.3 g vs. 110.2 g FI, and 2.38 vs. 2.04 FCR, in 0% vs. 9% SP, respectively). When incorporating SP into the diets of HS-layers, the negative impacts of HS were remarkably relieved (p < 0.05). Therefore, diets containing 9% SP could be used as a promising approach to improve the productive and physiological performance of laying hens, particularly under heat stress conditions.

Microbiome and ileum transcriptome revealed the boosting effects of selenium yeast on egg production in aged laying hens

The declines in laying performance during the late production period have adverse effects on the length of the production cycle. Improving the nutrition of laying hens is a crucial measure to reverse this declination. This study investigated the effect of selenium yeast (SY) on egg production, ileal gene expression and microbiota, as well as elucidating their associations in aged laying hens. A total of 375 Jinghong laying hens at 76 weeks old were randomly assigned into 5 dietary treatments, which included a selenium-deficient basal diet based on corn-soybean meal, and dietary supplementation of SY at 0.15, 0.30 and 0.45 mg/kg, and sodium selenite at 0.45 mg/kg. The results showed that SY ameliorated the depression in aged laying performance in the 0.30 mg/kg group (P < 0.01). Selenium yeast significantly increased ileum selenium concentration (P < 0.05), and SY groups had higher selenium deposition efficiency than the sodium selenite group. Functional enrichment and Short Time-series Expression Miner (STEM) analysis indicated that SY activated metabolic progress (e.g., glycerolipid metabolism, glycerophospholipid metabolism, and fatty acid metabolism), immune response and oxidative stress response. Four hub genes including thioredoxin reductase 1 (TXNRD1), dihydrolipoamide dehydrogenase (DLD), integrin linked kinase (ILK) and leucine zipper tumor suppressor 2 (LZTS2) were involved in intestinal metabolism which was closely associated with selenium deposition/status. Moreover, the relative abundance of Veillonella, Turicibacter and Lactobacillus was significantly increased, but the relative abundance of Stenotrophomonas was significantly decreased by SY supplementation. Multi-omics data integration and Canonical correspondence analysis (CCA) showed that both the ileum selenium content and the laying rate were highly correlated with pathways and bacteria enriched in metabolism and immune response. Meanwhile, the “switched on” gene prostate stem cell antigen (PSCA) had a positive relationship with Veillonella and a negative relationship with the opportunistic pathogens Stenotrophomonas. Overall, our study offered insight for the further exploration of the role of SY on boosting egg production and balancing ileum intestinal flora in aged laying hens.

Dietary selenium sources alleviate immune challenge induced by Salmonella Enteritidis potentially through improving the host immune response and gut microbiota in laying hens

The aim of this study was to evaluate the effects of different selenium (Se) sources on the immune responses and gut microbiota of laying hens challenged with Salmonella enteritidis (S. Enteritidis). A total of 240 45-week-old layers were randomly divided into eight groups with six replicates per group according to a 4 × 2 factorial design, including a blank diet without Se supplementation (CON group) and three diets with 0.3 mg/kg Se supplementation from sodium selenite (IS group), yeast Se (YS group), and selenium-enriched yeast culture (SYC group), respectively. After 8 weeks of feeding, half of them were orally challenged with 1.0 ml suspension of 109 colony-forming units per milliliter of S. Enteritidis daily for 3 days. The serum was collected on days 3, 7, and 14, and the cecum content was collected on day 14 after challenge. There was no significant difference in laying performance among the eight groups before challenge. The S. Enteritidis challenge significantly decreased the laying performance, egg quality, GSH-Px, IgG, and IgM and increased the ratio of feed and egg, malondialdehyde (MDA), Salmonella-specific antibody (SA) titers, IL-6, IL-2, IL-1β, and INF-γ. However, SYC increased the level of GSH-Px and IgG and decreased IL-6, while YS decreased the level of IL-2 and IL-1β. What is more, Se supplementation decreased the SA titers to varying degrees and reduced the inflammatory cell infiltration in the lamina propria caused by S. Enteritidis infection. In addition, the S. Enteritidis challenge disrupted the intestinal flora balance by reducing the abundance of the genera Clostridium innocuum, Lachnospiraceae, and Bifidobacterium and increasing the genera Butyricimonas and Brachyspira, while Se supplementation increased the gut microbial alpha diversity whether challenged or not. Under the S. Enteritidis challenge condition, the alteration of microbial composition by the administration of different Se sources mainly manifested as IS increased the relative abundance of the genera Lachnospiraceae and Christensenellaceae, YS increased the relative abundance of the genera Megamonas and Sphingomonas, and SYC increased the genera Fusobacterium and Lactococcus. The alteration of gut microbial composition had a close relationship with antioxidant or immune response. To summarize, different Se sources can improve the egg quality of layers challenged by S. Enteritidis that involves elevating the immunity level and regulating the intestinal microbiota.

Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress

Heat stress (HS) induces deleterious effects on the performance of laying hens and causes economic losses for poultry industry. This study was carried out to investigate the organic effect of selenium-enriched yeast (SY) on relieving the performance, immunity and physiological deterioration induced by heat stress in laying hens. A total of 324, 28-week-old, Hy-Line Brown commercial chicken layers were randomly distributed into 4 treatments according to a 2 × 2 factorial design, with 9 hens × 9 replicates per treatment (n = 81). From 30 to 34 weeks of age, layers were exposed to 2 temperature treatments (the HS treatment groups): a thermoneutral temperature at 24°C and a heat stress at 35°C. Layers were further assigned into the 2 subgroups according to dietary supplementation with organic selenium-enriched yeast (the SY treatment groups) at either 0 or 0.4 mg/kg diet. Results indicated that all the aspects of the layer performance during the experimental period were impaired by exposure to HS, while SY supplementation improved the layer performance in both the HS and non-HS layers. Intestinal villi disruptions and liver necrotic hepatocytes were observed in the layers exposed to HS, while villi integrity and hepatocytic normality were enhanced by SY treatment. A significant (P < 0.05) decrease in the total leukocyte count, sheep red blood cell (SRBC) antibody titer, and T- and B-lymphocyte proliferation along with an increase in the heterophils/lymphocytes (H/L) ratio were observed in the HS layers compared to non-HS layers. On the contrary, SY treatment significantly (P < 0.05) improved the immune function traits in both the HS layers and non-HS layers. Furthermore, the SY treatment plays an important role in mitigating the oxidative stress and inflammation induced by HS, displaying lower levels of plasma corticosterone, lipid peroxidation, interleukin-1β, and tumor necrosis factor-α in HS layers supplemented with SY compared to HS layers without SY supplementation. These results conclude that addition of SY to the diet of laying hens could be applied as a potential nutritional approach to relieve the deterioration effects of heat stress on the immunity, physiological status, and productive performance of laying hens.

The health benefits of selenium in food animals: a review

Selenium is an essential trace mineral important for the maintenance of homeostasis in animals and humans. It evinces a strong antioxidant, anti-inflammatory and potential antimicrobial capacity. Selenium biological function is primarily achieved by its presence in selenoproteins as a form of selenocysteine. Selenium deficiency may result in an array of health disorders, affecting many organs and systems; to prevent this, dietary supplementation, mainly in the forms of organic (i.e., selenomethionine and selenocysteine) inorganic (i.e., selenate and selenite) sources is used. In pigs as well as other food animals, dietary selenium supplementation has been used for improving growth performance, immune function, and meat quality. A substantial body of knowledge demonstrates that dietary selenium supplementation is positively associated with overall animal health especially due to its immunomodulatory activity and protection from oxidative damage. Selenium also possesses potential antiviral activity and this is achieved by protecting immune cells against oxidative damage and decreasing viral replication. In this review we endeavor to combine established and novel knowledge on the beneficial effects of dietary selenium supplementation, its antioxidant and immunomodulatory actions, and the putative antimicrobial effect thereof. Furthermore, our review demonstrates the gaps in knowledge pertaining to the use of selenium as an antiviral, underscoring the need for further in vivo and in vitro studies, particularly in pigs.

Effects of Different Selenium Sources on the Laying Performance, Egg Quality, Antioxidant, and Immune Responses of Laying Hens under Normal and Cyclic High Temperatures

The aim of this study was to evaluate the effects of different selenium (Se) sources on the laying performance, egg quality, antioxidant, and immune responses of laying hens under different temperatures. In an 8-week experiment, a total of 480 44-week-old laying hens were randomly divided into 8 groups, with 6 replicates for each group and 10 hens per replicate, and fed with a basal diet (BK), basal diet with 0.3 mg/kg of Se from sodium selenite (SS), from Se yeast (SY), or from selenium-enriched yeast culture (SYC) under normal temperature (NT, 26 ± 2 °C) and cyclic high temperature (CHT, 26 ± 2 °C~33 ± 2 °C). CHT decreased the laying performance and serum levels of Se, immunoglobulin G (IgG), and interleukin-10 (IL-10), and significantly increased the serum free triiodothyronine (FT3), deiodinase-I (DI-I), and heat stress protein (HSPs) (p < 0.05). In addition, SYC increased the egg yolk color, and SS increased serum IgG level. SS, SY, and SYC reduced the level of interleukin-6 (IL-6) (p < 0.05). In conclusion, Se can increase egg yolk color, antioxidant capacity, and immune capacity under heat stress, and the effect of organic Se is better than that of inorganic Se.

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 22 to 42 d of age

The current NRC dietary selenium (Se) requirement (0.15 mg/kg) of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986, which might not be applicable to modern classes of rapidly growing broilers. The present experiment was conducted to determine the optimal dietary Se level for meeting metabolic and functional Se requirements of broilers fed a corn-soybean meal diet from 22 to 42 d of age. A total of 336 Arbor Acres male broilers at 22 d old were randomly assigned to 1 of 6 treatments with 7 replicates and fed a basal corn-soybean meal diet (control, containing 0.014 mg Se/kg) and the basal diet supplemented with 0.10, 0.20, 0.30, 0.40, or 0.50 mg Se/kg from Na₂SeO₃ for 21 d. The results showed that the Se concentrations in plasma, liver, kidney, pancreas, breast and thigh muscles, the activity of glutathione peroxidase (GPX) in plasma, liver and kidney, the mRNA expression levels of Gpx4, selenoprotein (Seleno) h and Selenou in liver, Selenop and Selenoh in kidney, and the protein expression levels of GPX4 in the liver and kidney of broilers were affected (P < 0.05) by supplemental Se level, and increased quadratically (P < 0.05) with the increase of supplemental Se level. The estimates of optimal dietary Se levels were 0.10 to 0.49 mg/kg based on the fitted broken-line or asymptotic models (P < 0.0001) of the above Se concentration indices, and 0.08 to 0.37 mg/kg based on the fitted broken-line, quadratic or asymptotic models (P < 0.007) of the above selenoprotein expression indices. These results indicate that the optimal dietary Se levels would be 0.49 mg/kg to support the maximum Se concentrations and 0.37 mg/kg to support the full expression of selenoproteins in plasma and various tissues of broilers fed a corn-soybean meal diet from 22 to 42 d of age.

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.

Dietary Selenized Glucose Increases Selenium Concentration and Antioxidant Capacity of the Liver, Oviduct, and Spleen in Laying Hens

Selenized glucose (SeGlu) is a new type of organic selenium (Se) that is synthesized through the selenide reaction of glucose with sodium hydrogen selenide. This study aimed to clarify the influence of dietary SeGlu on the Se level and antioxidant capacity of the liver, oviduct, and spleen in laying hens. A total of 360, 60-week-old, Hy-Line Brown laying hens were randomly assigned to three treatment groups: a basal diet alone (control group, without adding exogenous Se) or the basal diet supplemented with 0.3 mg/kg of Se from sodium selenite (SS) or 5 mg/kg of Se from SeGlu. Diets with SeGlu increased Se levels in the liver, oviduct, and spleen of laying hens (P < 0.001). Compared with the control and SS groups, diet supplemented with SeGlu enhanced glutathione peroxidase (GSH-Px) activity and total antioxidant capacity (T-AOC) in the spleen and oviduct as well as the scavenging ability of 2, 2-diphenyl-1-picrylhydrazyl free radical (DPPH•) in the oviduct (P < 0.05). Compared with the control group, SeGlu treatment resulted in an increase (P < 0.05) in GSH-Px activity, T-AOC, and scavenging abilities of hydroxyl radical and DPPH• in the liver of hens. In addition, dietary SeGlu and SS decreased the hydrogen peroxide level in the oviduct in comparison to the control group (P < 0.05). Therefore, dietary SeGlu increased Se concentration and antioxidant ability in the liver, oviduct, and spleen of laying hens. Moreover, SeGlu may be used as a potential source of Se additive in laying hen production.

Hydroxy-Selenomethionine Improves the Selenium Status and Helps to Maintain Broiler Performances under a High Stocking Density and Heat Stress Conditions through a Better Redox and Immune Response

This study has determined whether hydroxy-selenomethionine (OH-SeMet) exerts a better protective action on broilers against environmental stress than sodium selenite (SS) or seleno-yeast (SY). Day-old male Cobb 500 broilers (12 cages/diet, 9 broilers/cage) were fed a selenium (Se)-deficient diet (0.047 mg/kg) supplemented with SS, SY or OH-SeMet at 0.3 mg Se/kg under a high stocking density and heat stress condition for six weeks. OH-SeMet improved the FCR and Se concentration in the tissues than SS and SY. SY and OH-SeMet both reduced the serum cortisol, T3, IL-6, IgA, IgM and LPS, more than SS, while only OH-SeMet further increased IL-10 and IgG. SY and OH-SeMet improved the intestinal morphology and increased the T-AOC, TXRND, SELENON and OCCLUDIN activities but decreased CLAUDIN2 in the jejunum than SS, while OH-SeMet further improved these values than SY. SY and OH-SeMet both increased SELENOS and TXNRD2 in the muscles than SS, and OH-SeMet further raised T-AOC, GPX4, SELENOP, SELENOW and TXNRD1, and reduced malondialdehyde and protein carbonyl in the muscles than SS and SY. OH-SeMet showed a better ability to maintain the performance and the redox and immune status of broilers under a high stocking density and heat stress challenge than SS and SY.

Impacts of heat stress on immune responses and oxidative stress in farm animals and nutritional strategies for amelioration

Heat stress is one of the greatest challenges for the global livestock industries as increased environmental temperature and humidity compromises animal production during summer leading to devastating economic consequences. Over the last 30 years, significant developments have been achieved in cooling and provision of shade and shelter to mitigate heat stress reducing some of the losses associated with heat stress in farm animals. However, the recent increase in the incidence of heat waves which are also becoming more severe and lasting longer, due to climate change, further accentuates the problem of heat stress. Economic losses associated with heat stress are both direct due to loss in production and animal life, and indirect due to poorer quality products as a result of poor animal health and welfare. Animal health is affected due to impaired immune responses and increased reactive oxygen species production and/or deficiency of antioxidants during heat stress leading to an imbalance between oxidant and antioxidants and resultant oxidative stress. Research over the last 20 years has achieved partial success in understanding the intricacies of heat stress impacts on oxidative stress and immune responses and developing interventions to ameliorate impacts of heat stress, improving immune responses and farm animal health. This paper reviews the body of knowledge on heat stress impacts on immune response in farm animals. The impacts of heat stress on both cell-mediated and humoral immune responses have been discussed identifying the shift in immune response from cell-mediated towards humoral response, thereby weakening the immune status of the animal. Both species and breed differences have been identified as influencing how heat stress impacts the immune status of farm animals. In addition, crosstalk signaling between the immune system and oxidative stress has been considered and the role of antioxidants as potential nutritional strategies to mitigate heat stress has been discussed.

Selenium source and level on performance, selenium retention and biochemical responses of young broiler chicks

Background

Selenium (Se) has been recognized as an essential micronutrient for nearly all forms of life. In recent decades, broiler responses to dietary Se supplemental levels and sources have received considerable attention. On environmental grounds, organic trace mineral utilization in practical broiler feeds has been defended due to its higher bioavailability. In such feeds, trace minerals are provided simultaneously in the same supplement as inorganic salts or organic chelates, a fact commonly ignored in assays conducted to validate organic trace mineral sources. The current assay aimed to investigate growth and biochemical responses, as well as Se retention of growing chicks fed diets supplemented with organic and inorganic Se levels and where the trace minerals (zinc, copper, manganese, and iron) were provided as organic chelates or inorganic salts according to Se source assessed. In so doing, a 2 × 5 factorial arrangement was used to investigate the effects of sodium selenite (SS) and selenium-yeast (SY) supplemented in feeds to provide the levels of 0, 0.08, 0.16, 0.24, and 0.32 mg Se/kg.

Results

Chicks fed selenium-yeast diets had body weight (BW), and average daily gain (ADG) maximized at 0.133 and 0.130 mg Se/kg, respectively. Both Se sources linearly increased (P < 0.05) the glutathione peroxidase (GSH-Px) activity in chick blood but higher values were observed in sodium selenite fed chicks (P < 0.05). Both Se sources influenced thyroid hormone serum concentrations (P < 0.05). Chicks fed SY exhibited greater retention of Se in the feathers (P < 0.05). Relative bioavailability of selenium yeast compared with SS for the Se content in carcass, feathers, total and Se retention were, 126, 116, 125 and 125%, respectively. SY supplementation resulted in lower liver Se concentration as Se supplementation increased (P < 0.05).

Conclusions

Based on performance traits, the supplemental level of organic Se as SY in organic trace minerals supplement to support the maximal growth of broiler chicks is 0.133 mg Se/kg.

Effect of selenium supplementation on productive performance and antioxidant status of broilers under heat stress: a meta-analysis and a meta-regression

Heat stress and a high metabolic rate of broilers increase the production of reactive oxygen species, which must be removed by antioxidants to prevent oxidative stress. Selenium (Se) is a potent antioxidant as it is a structural part of glutathione peroxidase (GPx). Dietary supplementation of Se can help reduce the oxidative stress caused by heat-stress conditions. The aim was to evaluate the effect of Se supplementation on the performance and antioxidant status of broilers under heat stress, by using a meta-analysis approach, and to quantify the contribution to heterogeneity of the explanatory variables through a meta-regression procedure. A database of 74 trials was created from 56 published studies that met the following inclusion criteria: papers that reported a measure of effect size, sample size, measure of variability and random procedure. The response variables were GPx and malondialdehyde concentrations, DM intake, average daily gain, and feed conversion rate. Broiler line, Se source, and dosage, heat-stress level, days of experimentation, sample source (blood, liver or meat) and basal Se concentration were considered to be explanatory variables. All statistical analyses were performed in R software, by using the ‘meta’ and ‘Metafor’ packages for meta-analysis and meta-regression respectively. High concentrations of GPx were found in Se-supplemented broilers (&gt;1.76; P = 0.001), in comparison to control groups. However, when the random model was applied to GPx studies, it showed high heterogeneity (I2 = 95.4%), which was reduced (I2 = 61.5) when heat-stress temperature, Se source and its dosage and tissue sample were included as covariates in the meta-regression analysis. The highest standard mean difference of GPx was founded in studies that reported supplementation with inorganic Se sources (2.92), in comparison to supplementation with organic and nano-Se sources (1.66 and 1.44 respectively). The standard mean differences of malondialdehyde and feed conversion rate were significantly lower (&lt;0.66 and &lt;0.11 respectively) in supplemented broilers. Heterogeneity of all variables decreased when the explanatory variables were included in the mixed-regression model. Our findings confirmed that Se supplementation improves the broiler’s antioxidant status and productive performance. However, the response level was affected by dosage and source of Se and the level of heat stress.

The effect of selenium source on the oxidative status and performance of broilers reared at standard and high ambient temperatures

1. This study investigated the oxidative status of broilers fed diets containing selenium (Se) from 14 to 35 d of age and reared at two different constant temperatures. Measurements of oxidative status included blood glutathione peroxidase (GSH-Px) and plasma total antioxidant status (TAS). Other variables included feed intake (FI), weight gain (WG), feed conversion ratio (FCR), Se levels in breast and liver tissue, jejunal villus morphometry, percentage weight of organs in relation to body weight; apparent metabolisable energy adjusted for nitrogen (AMEn); dry matter retention (DMR); fat retention (FR) and nitrogen retention (NR).2. The experiment started at 14 d of age, when 240 birds were randomly allocated to 48 pens (12 pens in four rooms). Treatments included a control diet 1 (SFC; 209.4 g/kg CP and 12.98 MJ/kg ME and no added Se containing saturated fat); diet 2 (SFSe) the control plus 12.605 mg/kg Se additive; diet 3 (USFC) was a second control diet (208.2 g/kg CP and 13.10 MJ/kg ME with no added Se containing unsaturated fat as rapeseed oil); diet 4 (USFSe) was the latter control plus 12.605 mg/kg Se additive. Two rooms were kept at a standard temperature of 20°C (ST) and two rooms were kept at high temperature of 35°C (HT).3. A temperature x Se interaction existed for GSH-Px in birds reared at ST (P < 0.05), and these birds had the highest levels of Se in liver tissue (P < 0.05). Fat x Se interactions were evident in breast tissue with highest levels in USFSe (P < 0.05). Adding Se improved jejunal VH: CD in USFSe fed birds (P < 0.001).4. Birds reared at ST had higher FI and WG than those reared at HT (P < 0.001), and had lower FCR than those reared at HT (P < 0.05). AMEn (MJ/kg DM) and FR were higher in birds fed USF diets, and lowest in birds fed SF (P < 0.50 and P < 0.001 respectively). NR was highest in birds raised at ST (P < 0.50).5. Broiler growth performance was reduced by HT. Oxidative status and Se in liver tissue was improved by adding Se in both diets.

Effects of Selenium-Enriched Yeast on Performance, Egg Quality, Antioxidant Balance, and Egg Selenium Content in Laying Ducks

This study investigated the effects of dietary selenium-enriched yeast (Se yeast) supplementation on the laying performance, egg quality, plasma antioxidant balance, and egg selenium (Se) content in laying Longyan ducks. A total of 480 32-week-old ducks were randomly divided into four dietary treatments, each consisting of six replicates of 20 ducks. The dietary treatments were a control basal diet and basal diets with supplementation of 0.05, 0.15, and 0.25 mg Se/kg via Se yeast. The analyzed Se contents of the four diets were 0.15, 0.21, 0.36, and 0.43 mg Se/kg, respectively. Dietary Se yeast supplementation had no apparent effects on laying performance and egg quality (p > 0.05), but it improved the antioxidant balance of ducks, as inferred by greater glutathione peroxidase and catalase activities, and decreased the malondialdehyde content in plasma of ducks (p < 0.05). It was suggested that the Se content in the basal diet containing 0.15 mg/kg of Se requirement is adequate for productive performance, but not for the antioxidant balance of laying ducks. Besides that, the Se contents in the yolk, albumen, and whole egg increased linearly as the Se supplementation levels increased. With more feeding days, the Se contents in the yolk and whole egg from non-Se-yeast-supplemented ducks increased linearly (p < 0.05), while those from Se-yeast-supplemented ducks showed a quadratic relationship (p < 0.05). In conclusion, the Se content of the basal diet at 0.15 mg/kg was adequate for laying performance and egg quality traits in laying ducks. Dietary Se yeast supplementation is beneficial to improve the antioxidant balance of laying ducks and increase the Se deposition in eggs for producing Se-enriched eggs. Based on the quadratic model or the quadratic broken-line model analyses, supplemental 0.19 mg Se/kg via Se yeast, with a total equivalent of 0.34 mg Se/kg in the diet, could provide the optimum antioxidant balance in laying ducks. Dietary supplementation of 0.25 mg Se/kg via Se yeast, with a total equivalent of 0.40 mg Se/kg in the diet, could lead to achieving the desired Se content in the whole egg.

Effect of Different Selenium Sources on Growth Performance, Tissue Selenium Content, Meat Quality, and Selenoprotein Gene Expression in Finishing Pigs

Se-methylselenocysteine (MeSeCys) is a natural organic selenium (Se) supplement. However, its effects on animal nutrition are poorly understood. This study compared the effects of sodium selenite (SeNa), MeSeCys, and selenomethionine (SeMet) on immune function, tissue Se concentration, meat quality, and selenoprotein gene expression in pigs. A total of 72 finishing pigs were divided into four groups, which received a basal diet (BD, 0.1 mg Se/kg) without Se supplementation or one supplemented with SeNa, MeSeCys, or SeMet at a concentration of 0.25 mg Se/kg. Organic Se supplementation significantly increased the immune globulin A (IgA), IgG, and IgM serum levels compared with BD and SeNa groups (P < 0.05). There were no statistically significant differences in growth performance among the four groups. SeMet was more efficient in increasing Se concentrations in the heart, muscle, and liver than MeSeCys and SeNa (P < 0.05), while no statistically significant differences were observed between MeSeCys and SeNa. Se supplementation significantly decreased the pressing muscle loss compared with the BD group (P < 0.05). Meat color and pH were not significantly affected. Se supplement effects on liver selenoprotein gene mRNA level enhancement were ranked as follows: MeSeCys > SeMet > SeNa (P < 0.05). In muscle tissues, only the SELENOW mRNA level was significantly increased by the MeSeCys and SeMet treatment, compared with the SeNa group. In conclusion, SeMet was more efficient in increasing Se concentrations than MeSeCys and SeNa in pigs, while MeSeCys was more efficient in enhancing selenoprotein gene expression than SeMet and SeNa.

The effect of feeding different sources and levels of selenium on growth performance and antioxidant status of broilers raised at two different temperatures

1. This study examined the effects of different dietary sources and levels of selenium (Se) on growth performance, hepatic and breast meat Se content, glutathione peroxidase (GSH-Px) activity and total antioxidant status (TAS) in blood, when fed to broilers from 14 to 35 d of age and reared at two different temperatures (20°C and 35°C). 2. Five hundred and sixty male Ross 308 broilers were reared in a single floor pen and fed the same proprietary starter diet from 0 to 14 d age (229.9 g/kg CP and 12.67 MJ/kg ME, without Se supplementation). 3. The experiment started at 14 d age, and the birds randomly assigned to 112 raised-floor pens (0.36 m² area, 5 birds/pen). Each of the seven experimental diets were offered to birds in 16 pens within four rooms. Two rooms were at 20°C and two rooms were maintained at 35°C. The experimental diets were fed from 14 to 35 d age and contained 214.9 g/kg CP and 13.11 MJ/kg ME. The experimental diets were as follows; control diet containing background Se only (0.189 mg/kg; C); low level sodium selenite (0.376 mg/kg; LSS): high level sodium selenite (0.558 mg/kg; HSS); low level commercial B Traxim® Se (0.244 mg/kg) (LBT); high level B Traxim® Se (0.448 mg/kg; HBT); low level selenised yeast (0.290 mg/kg; LSY); high level selenised yeast (0.487 mg/kg; HSY). 4. Birds consumed more when raised at 20°C compared to birds reared at 35°C (P ≤ 0.05). Birds fed lower Se level reared at 35°C had higher weight gain versus those fed higher Se level (P < 0.05). Birds fed SY had the lowest feed intake, weight gain and FCE (P < 0.05). The greatest GSH-Px activity was observed in birds fed SS diets (P < 0.001). There were interactions between diet x level for TAS, which were highest in birds fed LBT compared to birds fed HBT (P < 0.05). Breast Se content was higher in birds fed HSY compared to LSY (P < 0.001). The highest hepatic Se was seen in birds fed SY and lowest in C (P < 0.001). 5. Birds fed BT diets showed similar levels of Se to those birds fed inorganic Se, and similar levels of GSH-Px to birds fed SY. Further comparative work with broilers fed BT and other Se supplemented diets may elucidate the findings from this report.

Relative bioavailability of selenium yeast for broilers fed a conventional corn-soybean meal diet

The present study was conducted to assess the relative bioavailability of selenium (Se) as Se yeast (SY) relative to sodium selenite (SS) for broilers fed a conventional corn-soybean meal diet. A total of 360 one-d-old Arbor Acres commercial broilers were randomly assigned to 5 treatments with 6 replicates per treatment in a completely randomized design involving a 2 (Se sources: SY and SS) × 2 (added Se levels: 0.20 and 0.40 mg Se/kg) factorial design of treatments plus 1 (a Se-unsupplemented control diet) for 42 days. The results showed that Se concentrations in plasma, liver, heart, breast muscle, pancreas and kidney of broilers on d 21 and 42, glutathione peroxidase (GSH-Px) activity in the pancreas on d 21 as well as in the breast muscle and pancreas on d 42, and GSH-Px mRNA levels in the liver, heart, breast muscle and pancreas on d 21 increased linearly (p < .03) as levels of added Se increased. Furthermore, a difference (p ≤ .05) between SY and SS was detected for Se concentrations in plasma, liver, heart, breast muscle, pancreas and kidney, GSH-Px activity in pancreas on both d 21 and 42, as well as pancreatic GSH-Px mRNA level on d 21. Based on slope ratios from the multiple linear regressions of the above indices, the Se bioavailabilities of SY relative to SS (100%) were 111%-394% (p ≤ .05) when calculated from the Se concentrations in plasma, liver, heart, breast muscle, pancreas, kidney and GSH-Px activities in pancreas on d 21 and 42, as well as GSH-Px mRNA level in pancreas on d 21. The results from this study indicated that the Se from SY was more available for enhancing the Se concentrations in plasma or tissues and the expression and activity of GSH-Px in pancreas of broilers than the Se from SS.

Supplemental dietary selenium enhances immune responses conferred by a vaccine against low pathogenicity avian influenza virus

Selenium is a trace mineral that has antioxidant activities and can influence the immune system. However, antiviral effects of selenium have not been well studies in chickens. Chickens were therefore fed diets supplemented with two levels of two different sources of selenium (organic: selenium enriched yeast; SEY or inorganic: sodium selenite; SS). Chickens in the control groups did not receive supplemental dietary selenium. At 14 and 21 days of age, chickens were vaccinated with an inactivated low pathogenicity avian influenza virus (AIV, subtype H9N2) vaccine and blood samples were collected to determine the level of antibodies using hemagglutination inhibition (HI) and ELISA. At 30 days of age, chickens were also challenged with the same virus and swab samples were collected to assess the amount of virus shedding. Antibody levels, as measured by HI, increased significantly in the chickens that received higher levels of SEY at 16 days post vaccination. ELISA titers for IgM and IgY were higher in selenium supplemented chickens. Comparing to challenged control, virus shedding was lower in organic as well as inorganic selenium treated groups. Therefore, it may be concluded that supplemental dietary selenium could enhance vaccine conferred immunity thereby impacting protection against viral challenge in chickens.

Effect of Microbiota-Selenoprotein on Meat Selenium Content and Meat Quality of Broiler Chickens

Simple Summary

Lack of selenium (Se) is a worldwide problem which leads to an increased exposure to various diseases in animals and humans, as well as decreased productive and reproductive performance of animals. Due to the health benefits of this element, it can be supplemented to humans as multimineral containing inorganic Se and Saccharomycescerevisiae yeast, which mainly contains selenomethionine. On the other hand, selenium-containing food products—such as selenium-rich meat—can be considered as functional foods, which can be produced easily using organic selenium. This study states that Se-enriched breast meat with good antioxidant capacity can be produced using extracted bacterial selenoprotein.

Abstract

Selenium (Se) is able to transform from inorganic to organic forms via many bacterial species. This feature is being considered for delivering more bioavailable selenium compounds such as selenocysteine and selenomethionine for human and animal diet. This study investigated the effects of bacterial selenoprotein versus inorganic Se on the carcass characteristics, breast meat selenium content, antioxidant status, and meat quality of broiler chickens. One hundred and eighty chicks were randomly allotted to five treatments of a basal diet supplemented with no Se, sodium selenite, Enterobactercloacae Selenium (ADS1-Se), Klebsiellapneumoniae-Selenium (ADS2-Se), and Stenotrophomonasmaltophilia-Selenium (ADS18-Se). The results showed that bacterial selenoprotein has the ability to deposit more Se in the breast meat compared to sodium selenite. Both Se sources reduced breast meat drip loss, cooking loss, shear force, and 2-thiobarbituric acid reactive substances (TBARS) significantly. It also increased total antioxidant (TAC) and glutathione peroxidase (GSH-Px) in comparison with the negative control. The highest activity of (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) was found in bacterial selenoprotein. In conclusion, bacterial selenoprotein is more efficient than sodium selenite in increasing the breast meat Se deposition and oxidative capacity of broiler chickens. Therefore, it can be effectively used to produce Se-rich meat as a functional food.

Avian Stress-Related Transcriptome and Selenotranscriptome: Role during Exposure to Heavy Metals and Heat Stress

Selenium, through incorporation into selenoproteins, is one of the key elements of the antioxidant system. Over the past few years there has been increased interest in exploring those molecular mechanisms in chicken, responsible for the development of this protection system. In more detail, Cd/Pb poisoning and heat stress increase oxidation, mRNA levels of inflammatory proteins, and apoptotic proteins. Selenium seems to enhance the antioxidant status and alleviates these effects via upregulation of antioxidant proteins and other molecular effects. In this review, we analyze avian transcriptome key elements with particular emphasis on interactions with heavy metals and on relation to heat stress.

Effect of Dietary Modulation of Selenium Form and Level on Performance, Tissue Retention, Quality of Frozen Stored Meat and Gene Expression of Antioxidant Status in Ross Broiler Chickens

Simple Summary

Although the importance of usage of selenium as essential trace element in poultry production has been proven, the best source and level has not been fully addressed yet. Three different dietary selenium forms with three different levels were chosen to be added in broiler diet. Met-Se or nano-Se up to 0.6 mg/kg increased their performance and was more efficiently retained in the body than SeS. Frozen stored meat quality was improved in a dose-dependent manner especially with both Met-Se and nano-Se. Nano-Se was more potent than Met-Se, which in turn was more potent than inorganic Se against oxidative stress, which improved the quality of meat under frozen conditions.

Abstract

This study compares between different selenium forms (sodium selenite; SeS, selenomethionine; Met-Se or nano-Se) and levels on growth performance, Se retention, antioxidative potential of fresh and frozen meat, and genes related to oxidative stress in Ross broilers. Birds (n = 450) were randomly divided into nine experimental groups with five replicates in each and were fed diets supplemented with 0.3, 0.45, and 0.6 mg Se/kg as (SeS, Met-Se), or nano-Se. For overall growth performance, dietary inclusion of Met-Se or nano-Se significantly increased (p < 0.05) body weight gain and improved the feed conversion ratio of Ross broiler chicks at the level of 0.45 and 0.6 mg/kg when compared with the group fed the same level of SeS. Se sources and levels significantly affected (p < 0.05) its concentrations in breast muscle, liver, and serum. Moreover, Se retention in muscle was higher (p < 0.05) after feeding of broiler chicks on a diet supplemented with Met-Se or nano-Se compared to the SeS group, especially at 0.6 mg/kg. Additionally, higher dietary levels from Met-Se or nano-Se significantly reduced oxidative changes in breast and thigh meat in the fresh state and after a four-week storage period and increased muscular pH after 24 h of slaughter. Also, broiler’s meat in the Met-Se and nano-Se groups showed cooking loss and lower drip compared to the SeS group (p < 0.05). In the liver, the mRNA expression levels of glutathione peroxidase, superoxide dismutase, and catalase were elevated by increasing dietary Se levels from Met-Se and nano-Se groups up to 0.6 mg/kg when compared with SeS. Therefore, dietary supplementation with 0.6 mg/kg Met-Se and nano-Se improved growth performance and were more efficiently retained than with SeS. Both sources of selenium (Met-Se and nano-Se) downregulated the oxidation processes of meat during the first four weeks of frozen storage, especially in thigh meat, compared with an inorganic source. Finally, dietary supplementation of Met-Se and nano-Se produced acceptable Se levels in chicken meat offered for consumers.

Relative bioavailability of ultrafine sodium selenite for broilers fed a conventional corn-soybean meal diet

The particle size of selenium (Se) sources could affect Se absorption and utilization, and thus it is hypothesized that the Se bioavailability might be higher in ultrafine sodium selenite (USSe) than in sodium selenite (SSe) for broilers because of USSe's smaller particle size. An experiment was conducted to investigate the relative bioavailability of Se as USSe relative to SSe for broiler chicks fed a conventional corn-soybean meal diet. A total of 504 one-d-old Arbor Acres commercial male broilers were randomly allotted to 1 of 7 treatments with 6 replicates per treatment in a completely randomized design involving in a 2 (Se sources) × 3 (added Se levels) factorial arrangement of treatments plus a Se-unsupplemented control diet containing 0.05 mg Se/kg by analysis for 21 d. The 2 Se sources were USSe and SSe, and the 3 added Se levels were 0.15, 0.30, or 0.45 mg Se/kg. The Se concentrations, glutathione peroxidase (GSH-Px) activities, and mRNA relative abundances in plasma, liver, or pancreas of broilers on day 14 and 21 were determined. The results showed that Se concentrations, GSH-Px activities in plasma, liver, and pancreas, and mRNA relative abundances in the liver and pancreas of broilers on day 14 and 21 increased linearly (P < 0.05) as the added Se-level increased. Furthermore, a difference (P < 0.05) between USSe and SSe was detected for GSH-Px mRNA relative abundance in the pancreas of broilers on day 14. On the basis of the slope ratios from the multiple linear regression of the pancreatic GSH-Px mRNA relative abundance of broilers at 14 d of age on daily dietary analyzed Se intake, the Se bioavailability of USSe relative to SSe (100%) was 158% (P < 0.05). The results from this study indicated that the Se from USSe was more available to broilers than the Se from SSe in enhancing the pancreatic GSH-Px mRNA expression.

Effects of different selenium sources and levels on antioxidant status in broiler breeders

OBJECTIVE

This study was conducted with the objectives to examine the impacts of inorganic selenium (Se) and different types and levels of organic selenium on the serum and tissues Se status and antioxidant capacity in broiler breeders.

METHODS

Five hundred and forty 48-wk-old Lingnan Yellow broiler breeders were randomly assigned to 6 dietary treatments, provided same basal diet (0.04 mg/kg of Se) with 0.15 mg/kg, or 0.30 mg/kg of Se from sodium selenite (SS) or from selenium-enriched yeast (SY) or from selenomethionine (SM). The broiler breeders were slaughtered after an 8-wk experiment.

RESULTS

The results showed that SM was better than SY and SS, 0.30 mg/kg level was better than 0.15 mg/kg level in Se deposition (p<0.05) in serum, liver, kidney, pancreas and muscle; in antioxidant status, organic selenium had better effects than SS in broiler breeders (p<0.05), but SM and SY had a similar result, and 0.15 mg/kg level was better than 0.30 mg/kg (p<0.05).

CONCLUSION

The results demonstrated the evident advantage of supplementation of broiler breeders with 0.15 mg/kg SM, which improved tissue Se concentrations and antioxidant status, and can be considered as the best selenium source.

Effect of sodium selenite and selenium yeast on performance, egg quality, antioxidant capacity, and selenium deposition of laying hens

This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. Two-hundred-eighty-eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (corn-soybean meal diet) were supplemented with 0 [blank control (BC)], 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se-supplemented diets and the BC diet. The serum glutathione peroxidase (GSH-Px) activity was increased (P < 0.01) in hens fed Se-supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se-supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition.

Dietary Supplementation of Selenium-Enriched Probiotics Enhances Meat Quality of Broiler Chickens (Gallus gallus domesticus) Raised Under High Ambient Temperature

We investigated the effects of selenium-enriched probiotics (SP) on broiler meat quality under high ambient temperature and explore their underlying mechanisms. A total of 200 1-day-old male broiler chicks (Ross 308) were randomly allotted to four treatment groups, each with five replicates, in groups of ten birds. These birds were fed a corn-soybean basal diet (C), a basal diet plus probiotics supplementation (P), a basal diet plus Se supplementation in the form of sodium selenite (SS, 0.30 mg Se/kg), and a basal diet with the addition of selenium-enriched probiotics (SP, 0.30 mg Se/kg). The experiment lasted for 42 days. The birds were sacrificed by cervical dislocation, and the breast muscles were removed for further process. Our results showed that SP diet significantly increased (p < 0.05) the physical (pH, colors, water holding capacity, drip loss, shear force) and sensory characteristics of breast meat. All P, SS, and SP supplementation enhanced the antioxidant system by increasing (p < 0.05) the Se concentrations, glutathione (GSH) levels, activities of glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) whereas decreasing (p < 0.05) malondialdehyde (MDA) levels, with SP being higher than P and SS. Moreover, SP diet significantly upregulated (p < 0.05) the mRNA levels of glutathione peroxidase genes (GPx1, GPx4) while it downregulated heat stress biomarkers such as heat shock protein (HSP) 70 as compared to C, P, and SS diets. In conclusion, our findings suggest that SP may function as beneficial nutritive supplement that is capable of improving meat quality during the summer season.

The effect of dietary bacterial organic selenium on growth performance, antioxidant capacity, and Selenoproteins gene expression in broiler chickens

Background

Selenium (Se) is an essential trace mineral in broilers, which has several important roles in biological processes. Organic forms of Se are more efficient than inorganic forms and can be produced biologically via Se microbial reduction. Hence, the possibility of using Se-enriched bacteria as feed supplement may provide an interesting source of organic Se, and benefit broiler antioxidant system and other biological processes. The objective of this study was to examine the impacts of inorganic Se and different bacterial organic Se sources on the performance, serum and tissues Se status, antioxidant capacity, and liver mRNA expression of selenoproteins in broilers.

Results

Results indicated that different Se sources did not significantly (P ≤ 0.05) affect broiler growth performance. However, bacterial organic Se of T5 (basal diet +0.3 mg /kg feed ADS18 Se), T4 (basal diet +0.3 mg /kg feed ADS2 Se), and T3 (basal diet +0.3 mg /kg feed ADS1 Se) exhibited significantly (P ≤ 0.05) highest Se concentration in serum, liver, and kidney respectively. Dietary inorganic Se and bacterial organic Se were observed to significantly affect broiler serum ALT, AST, LDH activities and serum creatinine level. ADS18 supplemented Se of (Stenotrophomonas maltophilia) bacterial strain showed the highest GSH-Px activity with the lowest MDA content in serum, and the highest GSH-Px and catalase activity in the kidney, while bacterial Se of ADS2 (Klebsiella pneumoniae) resulted in a higher level of GSH-Px1 and catalase in liver. Moreover, our study showed that in comparison with sodium selenite, only ADS18 bacterial Se showed a significantly higher mRNA level in GSH-Px1, GSH-Px4, DIO1, and TXNDR1, while both ADS18 and ADS2 showed high level of mRNA of DIO2 compared to sodium selenite.

Conclusions

The supplementation of bacterial organic Se in broiler chicken, improved tissue Se deposition, antioxidant status, and selenoproteins gene expression, and can be considered as an effective alternative source of Se in broiler chickens.

Nanoselenium Supplementation of Heat-Stressed Broilers: Effects on Performance, Carcass Characteristics, Blood Metabolites, Immune Response, Antioxidant Status, and Jejunal Morphology

An experiment was conducted to investigate the effects of dietary nanoselenium supplementation at 0, 0.6 and 1.2 mg/kg of diet on growth performance, serum biochemical parameters, immune response, antioxidant capacity, and jejunal morphology of 29-d-old male broilers subjected to heat stress at 37 ± 1°C for 14 d. Broilers were fed for 42 d on the experimental diets. The results showed that nanoselenium supplementation had no effect on growth performance, but it supplementation at the rate of 1.2 mg/kg diet decreased the serum concentration of cholesterol prior to the heat exposure. Further, dietary nanoselenium supplementation linearly increased the high-density lipoprotein cholesterol concentration, while linearly decreased those of low-density lipoprotein cholesterol and aspartate aminotransferase in the serum before applying heat stress. Compared with thermoneutral temperature, heat stress reduced body mass gain, feed intake, percentages of carcass, breast, leg, abdominal fat, bursa of Fabricius, thymus, antibody response against sheep red blood cells, serum concentration of protein, erythrocyte activities of glutathione peroxidase and superoxide dismutase, jejunal villus height, and villus height to crypt depth ratio, while increased feed conversion ratio, percentages of liver, gizzard, pancreas, gallbladder, heart, and the concentrations of aspartate aminotransferase and malondialdehyde. Dietary supplementation of nanoselenium linearly reduced the abdominal fat and liver percentages, while linearly increased the activity of glutathione peroxidase and villus height in heat-stressed broilers. Furthermore, the lower level of nanoselenium decreased the percentages of gizzard and heart in broilers under heat stress. The diet supplemented with 1.2 mg/kg nanoselenium improved feed conversion ratio and increased antibody response against sheep red blood cells, activity of superoxide dismutase, and villus height to crypt depth ratio, but decreased the serum concentrations of cholesterol, low-density lipoprotein cholesterol, and malondialdehyde in heat-stressed broilers. The results suggest that supplemental nanoselenium improved growth performance, internal organs health, immune response, and jejunal morphology by alleviating the oxidative stress induced by heat stress.

Dietary Antioxidants: Potential Anticancer Agents

There are several extrinsic and intrinsic factors involving reactive oxygen species that play critical roles in tumor development and progression by inducing DNA mutations, genomic instability, and aberrant pro-tumorigenic signaling. There are various essential micronutrients including minerals and vitamins in the diet, which play pivotal roles in maintaining and reinforcing antioxidant performance, affecting the complex network of genes (nutrigenomic approach) and encoding proteins for carcinogenesis. A lot of these antioxidant agents are available as dietary supplements and are predominant worldwide. However, the best antioxidant micronutrient (or a combination of micronutrients) for reducing cancer risks is unknown. The purpose of this review is to survey the literature on modern biological theories of cancer and the roles of dietary antioxidants in cancer. The roles and functions of antioxidant micronutrients, such as vitamin C (ascorbate), vitamin E (alpha-tocopherol), selenium, and vitamin A, provided through diet for the prevention of cancer are discussed in the present work.

The effect of selenium and polysaccharide of Atractylodes macrocephala Koidz. (PAMK) on endoplasmic reticulum stress and apoptosis in chicken spleen induced by heat stress

Endoplasmic reticulum (ER) stress and oxidative stress are involved in different types of stress induced injuries.

Selenium Deficiency Activates Heat Shock Protein Expression in Chicken Spleen and Thymus

Heat shock proteins (Hsps) are protective proteins present in nearly all species; they are used as biomarkers of various stress conditions in humans, animals, and birds. Selenium (Se) deficiency, which can depress the production of Hsps, can cause chicken tissue injuries. To investigate Hsp production, mRNA, and protein levels in Se-deficient chicken spleens and thymuses, a total of 180 1-day-old sea blue white laying hens (90 chickens/group) were harvested in two groups (the control group and the Se-deficient group) in 15, 25, 35, 45, and 55 days, respectively. The results showed that mRNA levels of Hsp27, Hsp40, Hsp60, Hsp70, and Hsp90 were significantly increased in the spleens and thymuses of the Se-deficient group compared to the control group. Further protein levels of Hsp60, Hsp70, and Hsp90 were also significantly increased in the spleen and thymus of the Se-deficient group compared to the control group. Meanwhile, the spleen expression ratio of Hsp40 mRNA level and Hsp70 protein level were higher in the Se-deficient group than other proteins. In the thymus, the Hsp90 mRNA level and Hsp60 protein expression level were the highest level in the Se-deficient group among other proteins. Based on these results, we concluded that Se deficiency could induce a protective stress response in chicken by means of promoting the mRNA and protein expression of Hsps, thus easing the effects of Se deficiency to some extent.

The Protective Effects of Different Sources of Maternal Selenium on Oxidative Stressed Chick Embryo Liver

The experiment was conducted to investigate the protective effects of different sources of maternal selenium (Se) on oxidative stressed chick embryo. A total of 270 Lingnan Yellow broiler breeders were randomly allocated into three treatments with five replicates for 18 birds each. Breeders were fed with basal diet (BD) including 0.04 mg/kg Se or BD supplemented with sodium selenite (SS) or selenomethionine (SM) at a level of 0.15 mg Se/kg. The rearing experiment lasted for 8 weeks after an 8-week pre-test. Twenty eggs were collected from each replicate during the last 10-day, then incubated in a commercial incubator. On embryonic 17th, fertile eggs were transferred into 39.5 °C temperature stimulation for 6 h. Afterward, five eggs were randomly selected from each replicate for collecting chick embryo sample. The results showed that Se supplementation in the diet of breeders resulted in lower reactive oxygen species (ROS), heat shock protein 70 (HSP70), malondialdehyde (MDA), carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) concentrations and higher glutathione peroxidase (GPx), total superoxide dismutase (T-SOD), and catalase (CAT) activities in heat stress treated chick embryo (P < 0.05), and ROS, MDA, carbonyl, 8-OHdG concentrations in SM treatment were lower than those in SS treatment (P < 0.05). Se supplementation elevated cellular glutathione peroxidase (GPx1) mRNA level and activity, cytoplasmic thioredoxin reductase (TrxR1) activity and selenoprotein P (SelP) mRNA and protein level (P < 0.05), and maternal SM showed a higher value than maternal SS in upregulating GPx1, TrxR1, and SelP mRNA levels as well as GPx1 and TrxR1 activities or SelP protein level (P < 0.05). This study indicated that maternal Se can enhance antioxidative capacity and reduce ROS concentration and oxidative damage by upregulating the expression of antioxidative selenoprotein, and maternal SM is superior to SS in heat stress treated chick embryo.

Effects of Dietary Nano-Selenium Supplementation on Growth Performance, Antioxidative Status, and Immunity in Broiler Chickens under Thermoneutral and High Ambient Temperature Conditions

The objective of the present study was to examine the effects of nano-selenium on growth performance, antioxidative status, and immune function in broiler chickens reared under thermoneutral (22±1°C) or high ambient temperature (35±1°C) conditions. Thirty-six broiler chicks at 15d old were randomly divided into 6 treatments in a 3×2 factorial design. The main factors included the dietary supplementation (basal diet without Se supplementation [control], basal diet with 0.3 mg of nano-elemental Se per kilogram of diet [nano-Se], and basal diet with 0.3 mg of sodium selenite per kilogram of diet [SSe]) and the ambient temperature challenge (22±1°C or 35±1°C). The birds were given the experimental diets from 15 to 30 d of age. High ambient temperature significantly depressed body weight gain, feed intake, feed conversion ratio, breast muscle weight, and abdominal fat weight, while feeding nano-Se clearly alleviated these negative effects of high ambient temperature. In addition, feeding nano-Se increased glutathione peroxidase mRNA expression in liver and alleviated the negative effects of high ambient temperature via reducing the malondialdehyde content in liver and breast muscle. Furthermore, feeding nano-Se increased mRNA expression of cytokine genes (interleukins 2 and 6) under both thermoneutral and high ambient temperature conditions. Under both thermoneutral and high-temperature conditions, broiler chickens fed nano-Se had higher Se and vitamin E concentrations in breast muscle than broiler chickens fed the control diet. In contrast, feeding SSe at the same dose as nano-Se did not alleviate the negative effects of high ambient temperature on broiler chickens. In conclusion, dietary supplementation with nano-Se at 0.3 mg/kg diet might enhance growth performance by improving antioxidative or immune properties in broilers reared under high ambient temperature.

Effects of different dl-selenomethionine and sodium selenite levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers

This trial was conducted in a 2 × 3 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different dl-selenomethionine (dl-Se-Met) and sodium selenite (SS) levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers. A total of 840 Ross 308 broilers (7 days old) were allocated by body weight to seven treatments (three replicates of 40 birds each treatment) including (1) basal diet (containing 0.04 mg of selenium (Se)/kg; control) without supplementary Se; (2, 3 and 4) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as SS; (5, 6 and 7) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as dl-Se-Met. The experiment lasted 42 days. The results revealed that dietary Se supplementation improved (p < 0.05) average daily gain, feed efficiency, immune organ index, serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) and triiodothyronine (T3 ) concentrations and decreased (p < 0.01) thyroxine (T4 )/T3 ratio in serum compared with the control. Broilers receiving the dl-Se-Met-supplemented diets had higher (p < 0.05) feed efficiency, thymus index, the amounts of IgA, IgG, IgM and T3 as well as lower (p < 0.05) serum T4 concentrations and T4 /T3 ratio than those consuming the SS-supplemented diets. Serum IgA and IgM levels of broilers fed 0.15 mg Se/kg were significantly higher (p < 0.05) than those of broilers fed 0.05 or 0.25 mg Se/kg. In summary, we concluded that dl-Se-Met is more effective than SS in increasing immunity and promoting conversion of T4 to T3 , thus providing an effective way to improve the growth performance of broilers. Besides, based on a consideration of all experiment indices, 0.15 mg Se/kg was suggested to be the optimal level of Se supplementation under the conditions of this study.

Selenium and Polysaccharides of Atractylodes macrocephala Koidz Play Different Roles in Improving the Immune Response Induced by Heat Stress in Chickens

The aim of the present study was to investigate the effect of acute heat stress (HS) on the chicken immune response and to examine the role of selenium (Se) and the polysaccharides of Atractylodes macrocephala Koidz (PAMK) in immune regulation in the chicken immune system. Two hundred chickens were randomly divided into two groups: the HS group and the control (Con) group. These chickens were treated with Se (0.3 mg/kg), PAMK (200 mg/kg) alone, and a combination of Se (0.3 mg/kg) and PAMK (200 mg/kg). The cytokines; antioxidative enzymes; and HSP60, HSP70, and HSP90 levels were examined in chicken immune organs. The results indicated that HS-induced immune dysfunction included increased levels of TNF-α, IFN-γ, IL-2, IL-4, HSP60, HSP70, HSP90, and malondialdehyde (MDA) as well as decreased levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD) in immune organs (P < 0.05). Among the affected organs, the bursa of Fabricius was one primary target of HS. The immune dysfunction induced by HS was alleviated (P < 0.05 or not) by treatment with Se and PAMK in different immune organs. However, Se only regulated the expression of TNF-α and IFN-γ, and PAMK influenced more cytokines in immune organs. The results showed that Se specifically regulated the TNF-α and IFN-γ pathways. Therefore, Se and PAMK played different roles in improving the immune response in HS chicken.

Efficacy of selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.) in broilers

An experiment was conducted to determine the efficacy of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on performance, carcass characteristics, tissue Se concentration, and physiological responses of broilers in comparison to that of Se from Se-enriched yeast and sodium selenite. Three hundred and sixty male broilers, 10 days of age, were assigned to 6 groups, 4 replicates of 15 broilers each, according to the completely randomized design. The dietary treatments were the following: T1: control diet; T2: control diet plus 0.3 mg Se/kg from sodium selenite; T3: control diet plus 0.3 mg Se/kg from Se-enriched yeast; and T4, T5, and T6: control diet plus 0.3, 1.0, and 2.0 mg Se/kg from HPSeKS, respectively. The results found that dietary Se supplementation did not (p > 0.05) alter performance and carcass characteristics of broilers. Se supplementation increased (p < 0.05) Se concentrations in the liver and kidney of broilers. Heart tissue Se concentration of broilers fed Se from sodium selenite was lower (p < 0.05) than that of broilers fed Se from HPSeKS and Se-enriched yeast. Selenium from HPSeKS increased higher (p < 0.05) GSH-Px activity when compared to Se from sodium selenite and Se-enriched yeast. The results indicated that the efficacy of Se from HPSeKS was comparable in increasing tissue Se concentration, but higher in improving GSH-Px activity in Rbc when compared to those of Se from Se-enriched yeast.

The effect of selenium and polysaccharide of Atractylodes macrocephala Koidz. (PAMK) on immune response in chicken spleen under heat stress

The aim of the present study was to investigate the effect of selenium (Se), polysaccharide of Atractylodes macrocephala Koidz. (PAMK), and the combination of Se and PAMK on the immune response, heat shock protein (HSP) levels under heat stress (HS) condition in chicken spleen. Two hundred chickens were randomly divided into two groups, the HS group and the control (Con) group. Then these chickens were treated with Se (0.3 mg/kg), PAMK (200 mg/kg) alone, and the combination of Se (0.3 mg/kg) and PAMK (200 mg/kg). The antioxidative enzymes, cytokines contents, and expression levels of HSP27 and HSP70 were examined in chicken spleen. The results indicated that HS induced higher levels of TNF-α, IL-4, HSP27, HSP70, and MDA levels but lower level of IFN-γ, IL-2, Gpx, and SOD in spleen (P < 0.05). These responses were ameliorated by the treatment of Se, PAMK alone, and the combination of Se and PAMK (P < 0.05 or not) The results showed that under common condition, Se and PAMK could improve the immune response by enhancing the levels of some cytokines to proper levels; however, under HS condition, Se and PAMK could change the abnormal levels of cytokines and oxidative damages to ameliorate the injury induced by HS. In addition, there existed synergistic effect on the modulation of these biomarkers in chicken spleen between Se and PAMK. So both Se and PAMK play important roles in regulating the immune function in chicken. Considering the synergistic effect on immune regulation of PAMK, this herb deserves further investigation to evaluate its role in improving the effect of traditional immune regulators.

Productivity and selenium concentrations in egg and tissue of laying quails fed selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.)

This study aimed to determine the effectiveness of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on productive performance, egg quality, and Se concentrations in egg and tissue of laying quails. Two-hundred quails, 63 days of age, were divided into four groups. Each group consisted of five replicates and each replicate had ten birds, according to a completely randomized design. The experiment lasted for 6 weeks. The dietary treatments were T1 (control diet), T2 (control diet plus 0.2 mg Se/kg from sodium selenite), T3 (control diet plus 0.2 mg Se/kg from Se-enriched yeast), T4 (control diet plus 0.2 mg Se/kg from HPSeKS). The findings revealed that productive performance and egg quality of quails were not altered (p > 0.05) by Se sources. Whole egg Se concentrations of quails fed Se from HPSeKS and Se-enriched yeast were higher (p < 0.05) than that of quails fed the control diet. Breast muscle Se concentrations in quails fed Se from HPSeKS were higher (p < 0.05) than that of quails fed Se from sodium selenite and Se-enriched yeast. Heart tissue Se concentrations of quails fed Se from Se-enriched yeast and HPSeKS were similar (p > 0.05), but higher (p < 0.05) than that of quails fed Se from sodium selenite. The results reveal that Se from HPSeKS did not change the performance and egg quality of quails. The effectiveness of Se from HPSeKS was comparable to that of Se-enriched yeast, which was higher than that of Se from sodium selenite.

The effect of enriched milk with selenium and vitamin E on growth rate, hematology, some blood biochemical factors, and immunoglobulins of newborn goat kids

Thirty male and female (n = 15 for each one) Markhoz newborn goat kids (aged 7 ± 3 days) were distributed in a randomized block design in a 2 × 2 + 1 factorial arrangement: two levels of sodium selenite as a source of selenium (0.2 or 0.3 ppm Se), two levels of α-tocopherol acetate as a source of vitamin E (150 or 200 IU Vit E), and one control treatment with six repetitions per treatment (each replicate included three male and three female kids). Animals were fed daily by Se-Vit E-enriched milk (Se-Vit E treatments) or non-enriched milk (control treatment). Growth rate, hematology, and serum biological parameters were measured. The levels of serum albumin (P < 0.01), serum globulin (P < 0.05), total serum protein levels (P < 0.01), erythrocyte counts (RBC) (P < 0.001), hemoglobin (P < 0.001), hematocrit (P < 0.001), leukocyte counts (WBC) (P < 0.001), IgA (P < 0.05), IgG (P < 0.01), and IgM (P < 0.01) significantly differed among treatments, while no significant differences were observed for calcium, lymphocyte, neutrophil average daily gain and body weight among treatments. Kids feeding by enriched milk with 0.3 ppm Se and 200 IU Vit E had significantly higher serum total protein, globulin, RBC, IgA, IgG, and IgM compared to control and those fed by enriched milk to 0.2 ppm Se and 200 IU Vit E had significantly higher WBC counts.